MSG Toxicity - The Scientific Reports

I was amazed from reading over 1000 article abstracts that MSG (Monosodium Glutamate) is used for studying obesity (and its treatment by other means) by first administering MSG to test animals (often neonatal). Similarly, MSG was used as a 'known neurotoxin' to first induce certain conditions like neural lesions before further tests were carried out! Sentences like:
"Treatment of newborn mice with monosodium glutamate (MSG) is neurotoxic for hypothalamic arcuate nucleus (ARC) and causes obesity..."
"The hyperglycemia-accompanied obese mouse model was developed through an injection of monosodium glutamate (MSG)... "
"Administering monosodium glutamate (MSG) to neonatal rodents induces obesity and type 2 diabetes."
"It is well known that the administration of monosodium glutamate (MSG) in early life will cause disturbances in the reproductive neuroendocrine axis by destroying the neurons in the arcuate nucleus of the hypothalamus..."
"...were determined in adult rats that were treated in the neonatal period with monosodium L-glutamate (MSG) which has previously been shown to reliably produce destruction of arcuate nucleus perikarya. "
I haven't included those abstracts of reports here but they are available on request. (Admin)

Beware - MSG is also in vaccines!!


MSG Use Linked To Obesity - HERE

University of North Carolina at Chapel Hill

Summary:

People who use monosodium glutamate, or MSG, as a flavor enhancer in their food are more likely than people who don't use it to be overweight or obese even though they have the same amount of physical activity and total calorie intake, according to a study in the journal Obesity.

MONOSODIUM GLUTAMATE INCREASES VISCERAL SENSITIVITY IN A
MURINE MODEL OF IRRITABLE BOWEL SYNDROME - HERE (pdf available)

B.J. Brant(5), Y. Yu(4), A.E. Lomax(2), S. Vanner(1), C.J. Tuck(3)
1. queen's , Kignston, ON, Canada; 
2. Queen's University, Kingston, ON, Canada; 
3. Gastrointestinal diseases research unit, Queen's University, Kingston, ON, Canada; 
4. GIDRU, Queen's University, Kingston, ON, Canada; 5. Neuroscience, Queen's
University , Kingston, ON, Canada
Journal of the Canadian Association of Gastroenterology, Volume 3, Issue Supplement_1, February 2020, Pages 118–119.

...Conclusions: Our findings demonstrate that MSG increases visceral sensitivity to distension in our pre-clinical model of IBS. The increased permeability to MSG in WAS tissue and increased distension response in healthy control tissue when MSG is applied directly to the bath rather than intraluminally, suggests that MSG signals to the immune compartment or directly to the afferent nerve terminals. These findings support the rationale for future in vivo studies with this model to further clarify the mechanism.

Brain Lesions, Obesity, and Other Disturbances in Mice 
Treated with Monosodium Glutamate - HERE

John W. Olney (1)
1 Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
Science  09 May 1969: Vol. 164, Issue 3880, pp. 719-721

Abstract
In newborn mice subcutaneous injectionis of monosodium glutamate induced acute neuronal necrosis in several regions of developing brain including the hypothanamus. As adults, treated animals showed stunted skeletal development, marked obesity, and female sterility. Pathological changes were also found in several organs associated with endocrine function. Studies of food consumption failed to demonstrate hyperphagia to explain the obesity. It is postulated that the aduls syndrome represents a multifacted nueroendocrine disturbance arising from the disruption of developing nueral centers concered in the mediation of endocrine function.

Brain Lesions in an Infant Rhesus Monkey Treated with Monosodium Glutamate - HERE

John W. Olney (1), Lawrence G. Sharpe (1)
1 Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110
Science 17 Oct 1969, Vol. 166, Issue 3903, pp. 386-388

Abstract
In an infant rhesus monkey brain damage resulted from subcutaneously administered monosodium glutamate. Although a relatively high dose of monosodium glutamate was used, the infant was asymptomatic for a 3-hour observation period during which time hypothalamic neurons were undergoing a process of acute cell death. With the electron microscope it was observed that dendrites and cell bodies of neurons are the tissue components primarily affected in brain damage induced by monosodium glutamate.

Effect of monosodium glutamate on hematological parameters in Wistar rats- HERE 

Ashaolu J. O.1*, Ukwenya V. O.1, Okonoboh A. B.2, Ghazal O. K.2, Jimoh A. A. G.3
1 Department of Anatomy, College of Health Sciences, Bowen University, Iwo, Osun State, Nigeria.
2 Department of Anatomy, College of Health Sciences, University of Ilorin, Ilorin, Kwara State, Nigeria.
3 Department of Obstetrics and Gynaecology, College of Health Sciences, University of Ilorin, Ilorin, Kwara State, Nigeria.
International Journal of Medicine and Medical Sciences Vol. 3(6), pp. 219-222, June 2011  
(Full Length Research Paper)

Monosodium glutamate (MSG) is a food additive commonly consumed as a flavor enhancer. However, both animal models and human clinical reports have established its harmful effects.
...These findings support that MSG despite its flavoring functions, is detrimental to health. 


Obesity, Voracity, and Short Stature: The Impact 
of Glutamate on the Regulation of Appetite - HERE

M Hermanussen 1, A P García, M Sunder, M Voigt, V Salazar, J A F Tresguerres
1 Aschauhof Altenhof Germany.
Eur J Clin Nutr | 2006 Jan;60(1):25-31

Interpretation:

GLU is a widely used nutritional substance that potentially exhibits significant neuronal toxicity. Voracity, and impaired GH secretion are the two major characteristics of parenterally administered GLU-induced neuronal damage. GLU maintains its toxicity in animals even when administered orally. Males appear to be more sensitive than females. The present study for the first time demonstrates, that a widely used nutritional monosubstance--the flavouring agent MSG--at concentrations that only slightly surpass those found in everyday human food, exhibits significant potential for damaging the hypothalamic regulation of appetite, and thereby determines the propensity of world-wide obesity. We suggest to reconsider the recommended daily allowances of amino acids and nutritional protein, and to abstain from the popular protein-rich diets, and particularly from adding the flavouring agents MSG.


Evidence of alterations in brain structure and antioxidant status 
following ‘low-dose’ monosodium glutamate ingestion - HERE

Olakunle James Onaolapo(a,c), Adejoke Yetunde Onaolapo(b), M.A.Akanmu(c), OlayiwolaGbola(d)
a Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Osogbo, Osun State, Nigeria
b Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria
c Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
d Department of Clinical Pharmacy, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
Pathophysiology | Volume 23, Issue 3, September 2016, Pages 147-156

...Conclusion

The study showed morphological alterations consistent with neuronal injury, biochemical changes of oxidative stress and a rise in plasma glutamate and glutamine. These data therefore still support the need for cautious consideration in the indiscriminate use of MSG as a dietary flavor enhancer.


Monosodium glutamate induces cardiac toxicity via oxidative stress, 
fibrosis, and P53 proapoptotic protein expression in rats - HERE

Suzan M Hazzaa, Eman S El-Roghy, Mabrouk A Abd Eldaim & Ghada E Elgarawany
Enviornmental Science and Pollution Research | 31 March 2020


...Monosodium glutamate significantly reduced body weight, force of cardiac muscle contractility, serum level of high-density lipoprotein, and superoxide dismutase activity in cardiac muscle, while it significantly elevated heart rate, serum levels of total cholesterol, low-density lipoprotein, triacylglycerides, atherogenic index and troponin T, activities of serum lactate dehydrogenase and creatine kinase-MB, malondialdehyde concentration, and P53 protein expression in cardiac muscle. In addition, it induced myocardial degeneration, cellular infiltration, deposition of collagen in cardiac muscle, and periodic acid–Schiff staining reaction. This study indicated that MSG exerted long-lasting functional and structural alterations in the heart of male albino rats through induction of oxidative stress, atherogenesis, and apoptosis.


Monosodium glutamate induced testicular lesions in 
rats (histological study) HERE (pdf available)

Danlami Aisha
Federal University of Technology Minna
Middle East Fertility Society Journal 19(4) · October 2013

...Results
The body weight of rats was significantly increased and mainly histological alterations which included of hyaline material in the lumina of the seminiferous tubules and interstitial tissues and exfoliation of spermatocytes and spermatids in treated group. Many cells of the different types of spermatogenesis appeared necrotic with pyknotic nuclei. Dilated congested blood vessels and vacuolar degeneration were also been observed in the cells of seminiferous tubules in the treated group B. Conclusions MSG may have some deleterious effects on the testes of Wistar rats and by extension may contribute to the causes of male infertility. Thus, it is important to reconsider the usage of MSG as a flavor enhancer.


Additive-Induced Urticaria: Experience with Monosodium Glutamate (MSG) - HERE (pdf)

Ronald A. Simon - Department of Allergy and Immunology, Scripps Clinic, La Jolla, CA
The Journal of Nutrition | Volume 130, Issue 4, April 2000, Pages 1063S–1066S

...We conclude, with 95% confidence, that MSG is an unusual (,3% at most) exacerbant of chronic idiopathic urticaria.


Oral Monosodium Glutamate Administration Causes Early Onset of 
Alzheimer’s Disease-Like Pathophysiology in APP/PS1 Mice - HERE

Tanja Fuchsberger, Raquel Yuste, Sergio Martínez-Bellver, Jose Viña, M.Carmen Blanco-Gandia, Isabel Torres-Cuevas, Arantxa Blasco-Serra, Roman Arango, Jose Minarro, Marta Rodriguez-Arias, Vicent Teruel Marti & Ana Lloret
October 2019 Journal of Alzheimer's disease: JAD 72(3):1-19
Project: CHARACTERIZATION OF THE ACTIVITY OF PREFRONTAL CORTEX, HIPPOCAMPUS AND AMYGDALA IN A MODEL OF DEPRESSION. ANALYSIS OF EXPRESSION OF LEARNING PROTEINS.

Abstract

Glutamate excitotoxicity has long been related to Alzheimer's disease (AD) pathophysiology, and it has been shown to affect the major AD-related hallmarks, amyloid-β peptide (Aβ) accumulation and tau phosphorylation (p-tau). We investigated whether oral administration of monosodium glutamate (MSG) has effects in a murine model of AD, the double transgenic mice APP/PS1. We found that AD pathogenic factors appear earlier in APP/PS1 when supplemented with MSG, while wildtype mice were essentially not affected. Aβ and p-tau levels were increased in the hippocampus in young APP/PS1 animals upon MSG administration. This was correlated with increased Cdk5-p25 levels. Furthermore, in these mice, we observed a decrease in the AMPA receptor subunit GluA1 and they had impaired long-term potentiation. The Hebb-Williams maze revealed that they had memory deficits. We show here for the first time that oral MSG supplementation can accelerate AD-like pathophysiology in a mouse model of AD.

Monosodium glutamate affects cognitive functions in male albino rats - HERE (pdf available)

Wafaa M. Abdel Moneim, Heba A. Yassa, Rania A. Makboul & Nada A. Mohamed
Egyptian Journal of Forensic Sciences volume 8, Article number: 9 (2018)

Abstract
Background
Monosodium Glutamate is a silent toxin in our food, especially our kids’ food. Some of the products in the market contain MSG in a level exceed the European limit.

Results
MSG affected the cognitive function of treated rats in small and high doses of MSG. The weight of the animals in treated group with a high dose of MSG was significantly increased in comparison with the control group. Also, the cognitive function of the rats administered MSG affected significantly either in low dose and in high dose. Some of the studied commercial food in the market like Kapsa and Indomi contains a higher level of MSG more than the European limit.

Conclusion
MSG has many dangerous effects on health especially kids, so it is so necessary to declare its presence or absence and level on the labels of the products.


Patho-physiological and toxicological aspects of monosodium glutamate. HERE

Chakraborty SP(1).
1 a Department of Physiology , Ramananda College , Bishnupur , West Bengal , India.
Toxicol Mech Methods. 2019 Jul;29(6):389-396. 

Abstract

Nowadays, the life-line of urban population has been formed by commercial foods due to industrialization, urbanization, and rapid increase in working class. Commercial foods are time and energy saving foods but it compromising the nutritional value of foods. The term adulteration refers to the deliberate addition of compound which is usually not present in food. These compounds are known as food additives or food adulterant. Monosodium Glutamate (MSG) is one of the most common food additives. Several studies revealed that MSG has toxic effect on fetal development/fetus, children's, adolescent, and adults. Physiological complication associated with MSG toxicity are hypertension, obesity, gastrointestinal tract troubles, and impairment of function of brain, nervous system, reproductive, and endocrine system. The effect of MSG depends upon its dose, route of administration and exposure time. Public awareness may play a major role in controlling the food adulteration by working in collaboration with National testing facilities to scrutinize each commercial food article from time to time. The aim of this review article is to highlight the deleterious impact of MSG on human health.


Monosodium glutamate (MSG): A villain and promoter of 
liver inflammation and dysplasia - HERE

Yuko Nakanishi(a) Koichi Tsuneyam(a,b) Makoto Fujimoto(c), Thucydides L.Salunga(a,b,d), Kazuhiro Nomoto(a) Jun-Ling An(a),Yasuo Takano (a), Seiichi Iizuka(e), Mitsunobu Nagata(e) Wataru Suzuk(e), Tsutomu Shimada(e), Masaki Aburada(e), Masayuki Nakano(f) CarloSelmi(g,h) M. Eric Gershwin(h)
a Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
b 21st Century COE Program, University of Toyama, Toyama, Japan
c Department of Japanese Oriental Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
d Institute of Biology, University of the Philippines, Diliman, Quezon City, Philippines
e Research Institute of Pharmaceutical Sciences, Musashino University, Tokyo, Japan
f Division of Clinical Investigation, National Hospital Organization Chiba Medical Center, Chiba, Japan
g San Paolo Hospital School of Medicine, University of Milan, Italy
h Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, CA, USA
Journal of Autoimmunity | Volume 30, Issues 1–2, February–March 2008, Pages 42-50

...In particular, the murine steatohepatitis at 12 months was virtually undistinguishable from human NASH. Further, dysplastic nodular lesions were detected in some cases within the fibrotic liver parenchyma. We submit that MSG treatment of mice induces obesity and diabetes with steatosis and steatohepatitis resembling human NAFLD and NASH with pre-neoplastic lesions. These results take on considerable significance in light of the widespread usage of dietary MSG and we suggest that MSG should have its safety profile re-examined and be potentially withdrawn from the food chain...


Excitotoxic food additives--relevance of animal studies to human safety. - HERE

Olney JW.
Neurobehav Toxicol Teratol. 1984 Nov-Dec

Abstract
Evidence is reviewed supporting the view that excitotoxic food additives pose a significant hazard to the developing nervous system of young children. The following points are stressed: (1) although blood-brain barriers protect most central neurons from excitotoxins, certain brain regions lack such protection (a characteristic common to all vertebrate species); (2) regardless of species, it requires only a transient increase in blood excitotoxin levels for neurons in unprotected brain regions to be "silently" destroyed; (3) humans may be at particularly high risk for this kind of brain damage, since ingestion of a given amount of excitotoxin causes much higher blood excitotoxin levels in humans than in other species; (4) in addition to the heightened risk on a species basis, risk may be further increased for certain consumer sub-populations due to youth, disease or genetic factors; (5) despite these reasons for maintaining a wide margin of safety in the use of excitotoxins in foods, no safety margin is currently being observed, i.e., a comparative evaluation of animal (extensive) and human (limited) data supports the conclusion that excitotoxins, as used in foods today, may produce blood elevations high enough to cause damage to the nervous system of young children, damage which is not detectable at the time of occurrence but which may give rise to subtle disturbances in neuroendocrine function in adolescence and/or adulthood.


Effect of long-term monosodium glutamate administration on structure and 
functional state of the stomach and body weight in rats - HERE (Ukraine pdf)

Falalieieva TM, Kukhars'kyĭ VM, Berehova TV
Kyiv National Taras Shevchenko University, Ukraine
Bogomoletz Institute of Physiology
National Academy of Sciences of Ukraine

Abstract...It is concluded that the stimulating effect of MSG on the basal secretion of hydro­chloric acid in the stomach may be implicated in the pathogen­esis of a number of acid-dependent diseases. An excessive consumption of MSG can cause a «Chinese Restaurant Syn­drome» and gastritis, gastric and duodenal ulcers. Therefore, the maximum dose of MSG should be reconsidered taking into account its influence on the secretory capacity of the stomach. We also conclude that prolonged, excessive and systemic consumption of MSG causes obesity.


To study the effect of monosodium glutamate on histomorphometry 
of cortex of kidney in adult albino rats. HERE

Dixit SG(1), Rani P, Anand A, Khatri K, Chauhan R, Bharihoke V.
1 Department of Anatomy, All India Institute of Medical Sciences (AIIMS) , Jodhpur, Rajasthan , India and.
Ren Fail. 2014 Mar;36(2):266-70.

...Since MSG, as a food additive, was found to be toxic on various organs of the body by various researchers, it should perhaps be stopped from being used as a food additive. This may be a suggestion which needs validation in human studies.

Chronic toxicity of low dose monosodium glutamate in albino Wistar rats - HERE

Josiah Okwudili Nnadozie(1), Udunma Olive Chijioke(2), Okechukwu Charles Okafor(3), Daniel Bankole Olusina(3), Angus Nnamdi Oli(4), Patience Chiebonam Nwonu(5), Herbert Orji Mbagwu(6), and Chioli Pascal Chijioke(7)

1 Department of Chemical Pathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria
2 Department of Medical Laboratory Sciences, College Of Medicine, University Of Nigeria Enugu Campus, Enugu, Nigeria
3 Department of Morbid Anatomy, College Of Medicine, University Of Nigeria Enugu Campus, Enugu, Nigeria
4 Department of Pharmaceutical Microbiology And Biotechnology, Faculty Of Pharmaceutical Sciences, Nnamdi Azikiwe University, Agulu, Anambra State, Nigeria
5 Department of Pharmacology & Toxicology, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Enugu State Nigeria
6 Department of Pharmacology & Toxicology, College of Medicine, University of Uyo, Uyo, Akwa Ibom State Nigeria
7 Department of Pharmacology and Therapeutics, College of Medicine, University of Nigeria Enugu Campus, Enugu, Nigeria
BMC Res Notes. 2019; 12: 593.

...Chronic dosing with monosodium glutamate in albino Wistar rats (at a dose consistent with the human ADI) led to increased mortality, fertility impairment, and significant changes in major organ function tests and histology. 23 deaths were recorded in the rats fed with MSG additive, while mortality was zero in the control animals. Fertility was lower in rats on MSG (48 births) than in controls (117 births). The weight gain of the MSG rats was higher than in controls. Biochemical parameters and organ histology remained normal in control animals. In MSG-treated rats however, liver/renal function tests, fasting serum cholesterol and triglyceride, serum uric acid showed a significant rise at trimestrial time-points. Histology showed mild portal inflammation in MSG rats, with periglomerular fibrosis and interstitial nephritis in two rats, at 6–12 months.


‘Lone’ atrial fibrillation precipitated by monosodium glutamate and aspartame - HERE 

Craig G. Burkhart ⁎
University of Toledo College of Medicine, 5600 Monroe Street, Suite 106B, Sylvania, Ohio 43560, United States 2009

‘Lone’ atrial fibrillation infers absence of hypertension, heart failure, and coronary artery disease as the cause of this tachycardia. Korantzopoulos et al. [1] recently reviewed underlying causes and links associated with this entity, but failed to mention two epidemiological causes that receive considerable press, namely a flavor enhancer, monosodium glutamate (MSG) and an artificial sweetener, aspartame as the culprit of lone atrial fibrillation...

Possible Psychiatric Reactions to Monosodium Glutamate - HERE

N Engl J Med 1978; 299:902

This article has no abstract; the first 100 words appear below.

To the Editor: Two family members have demonstrated adverse reactions to monosodium glutamate that include psychiatric symptoms not previously described in this syndrome.My wife is a 38-year-old woman in good health with no previous history of psychiatric disorder. She had the typical acute five-hour to 12-hour monosodium glutamate reaction (including face and neck tightness, pressure behind the eyes, flushing, burning sensations in the chest and abdominal discomfort) after meals in restaurants and at home that included monosodium glutamate as a food additive.1 , 2 In addition to the acute symptoms, she and her friends and family noted a longer-term psychologic effect...

Combined Administration of Monosodium Glutamate and High Sucrose Diet Accelerates the Induction of Type 2 Diabetes, Vascular Dysfunction, and Memory Impairment in Rats. HERE

Saikrishna K(1), Kumari R(1), Chaitanya K(1), Biswas S(1), Nayak PG(1), Mudgal J(1), Kishore A(1), Nandakumar K(1).
1 Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal - 576104, Karnataka, India.
J Environ Pathol Toxicol Oncol. 2018;37(1):63-80.

...Feeding MSG in combination with HSD in rats significantly increased body weight, and produced hyperglycemia, dyslipidemia, and hyperinsulinemia. Animals developed frank diabetic complications, which included insulin resistance in skeletal muscle, hypertension, vascular dysfunction, nephropathy, and dementia. Histological studies revealed neuronal loss with necrotic bodies in the brain, reduction in glomerular count in kidney, and severe hypertrophy and hyperplasia in the islets of Langerhans. These results indicate the successful induction of type-2 diabetes along with several diabetic complications by combining MSG with HSD.

Neonatal treatment with monosodium glutamate lastingly facilitates 
spreading depression in the rat cortex - HERE (pdf)

Cássia Borges Lima(a), Geórgia de Sousa Ferreira Soares(a), Suênia Marcele Vitor(a), Bernardo Castellano(b), Belmira Lara da Silveira Andrade da Costa(c), Rubem Carlos Araújo Guedes(a)
a Department of Nutrition, Universidade Federal de Pernambuco, 50670901, Recife, Pernambuco, Brazil
b Unit of Medical Histology, Autonomous University of Barcelona, Spain
c Department of Physiology and Pharmacology, Universidade Federal de Pernambuco, 50670901, Recife, Brazil
Life Sciences | Volume 93, Issues 9–11, 17 September 2013, Pages 388-392

..Significance
The results demonstrate a novel, dose-dependent action of MSG in the developing brain, characterized by acceleration of CSD and significant microglial reaction in the cerebral cortex. The CSD effect indicates that MSG can influence cortical excitability, during brain development, as evaluated by CSD acceleration. Data suggest caution when consuming MSG, especially in developing organisms.


Investigation of the behavioral and neurochemical effects 
of monosodium glutamate on neonatal rats - HERE (pdf)

Ayşen ÇETİN KARDEŞLER(1), Eyüp BAŞKALE(2)
1 Department of Medical Biochemistry, Faculty of Medicine, Pamukkale University, Denizli, Turkey
2 Department of Biology, Faculty of Science and Letters, Pamukkale University, Denizli, Turkey
Turkish Journal of Medical Sciences | (2017) 47: 1002-1011

...Results: Considering the results of the behavioral test, when we compared the test values of the control group with the values of the MSG-injected groups we noted that there were significant differences in the statistical figures obtained. Additionally, we found that the statistical figures of some neurochemical parameters were also significantly different when we compared the values of the MSG group with the control values.

Conclusion: MSG injection has a clear effect on the neurochemical parameters, learning memory, and locomotor activities of rats.

Effect of monosodium L-glutamate (umami substance) on cognitive 
function in people with dementia - HERE (pdf available)

Minoru Kouzuki (1), Miyako Taniguchi (2), Tetsuya Suzuki1, Masaya Nagano (1), Syouta Nakamura (1), Yuto Katsumata (1), Hideki Matsumoto (3), Katsuya Urakami (1)
European journal of clinical nutrition 73(2):1 · October 2018

...Conclusions
Our results suggest that continued ingestion of MSG has an effect on cognitive function. Furthermore, the patients with improved questionnaires about palatability survey showed greater improvement in cognitive function.

A cross-sectional study on understanding and attitude of peri-urban 
Malaysians towards monosodium glutamate use - HERE

Kingston Rajiah(a), Shazia Qasim Jamshed(b), JeleineTee(a), Kar MunYong(a), Yusra Ahmad Zahdi(a), Wong Ia Ling(a)
a Department of Pharmacy Practice, School of Pharmacy, International Medical University, 57000, Kuala Lumpur, Malaysia
b Department of Pharmacy Practice, Kulliyyah of Pharmacy, International Islamic University Malaysia, Kuatan Campus, Pahang, Malaysia
Kasetsart Journal of Social Sciences | 24 May 2018

...This study revealed a relatively high percentage of respondents who were using or had previously used MSG. Significant associations were found between respondent's income and their understanding of MSG, with the higher income respondents having a better understanding.

Consumer perceptions and other influencing factors about 
monosodium glutamate in the United States - HERE

Shangci Wang & Koushik Adhikari
Article in Journal of Sensory Studies · July 2018

Monosodium glutamate (MSG) is a flavor enhancer commonly used in processed food products. However, its usage is controversial in the United States. This work aimed to understand the U.S. consumers’ perception about MSG and the factors influencing their attitudes. A survey questionnaire was developed based on a focus group study and then distributed in three geographical areas in the United States. Our results showed that U.S. consumers in general had a somewhat negative attitude toward MSG. Consumer's concern level about MSG was correlated with their risk and benefit perception about this ingredient. Information and natural food preference had a significant (p ≤ .05) positive contributions to risk perception. Consumers who had less negative feelings about chemicals tended to perceive more benefits from MSG. It was noticed that many respondents were confused about the differences between MSG and sodium chloride. Extracts from natural sources could be promising choices of MSG substitutes. Practical applications The survey created in this study threw light on understanding the U.S. consumers’ perception about monosodium glutamate (MSG). Findings from this work could be applied by food industry to better educate and communicate with consumers in terms of the issues related with MSG. In addition, with the knowledge of the factors driving consumer's perception, the food industry could use MSG substitutes and alternatives that meet the demands and satisfaction of today's consumer.

Monosodium glutamate (MSG) intake is associated with the 
prevalence of metabolic syndrome in a rural Thai population - HERE (pdf available)

Tonkla Insawang1, Carlo Selmi2,3, Ubon Cha’on1*, Supattra Pethlert1, Puangrat Yongvanit1, Premjai Areejitranusorn1,Patcharee Boonsiri1, Tueanjit Khampitak1, Roongpet Tangrassameeprasert1, Chadamas Pinitsoontorn1,Vitoon Prasongwattana1, M Eric Gershwin2and Bruce D Hammock4
Nutrition & Metabolism 2012, 9-50

Background: Epidemiology and animal models suggest that dietary monosodium glutamate (MSG) may contribute to the onset of obesity and the metabolic syndrome.

Results: The prevalence of the metabolic syndrome was significantly higher in the tertile with the highest MSG intake. Further, every 1 g increase in MSG intake significantly increased the risk of having the metabolic syndrome(odds ratio 1.14, 95% confidence interval-CI- 1.12 - 1.28) or being overweight (odds ratio 1.16, 95% CI 1.04 - 1.29),independent of the total energy intake and the level of physical activity.

Conclusion: Higher amounts of individual MSG consumption are associated with the risk of having the metabolic syndrome and being overweight independent of other major determinants.

(note the Competing interests in the rebuttal.

M.D.R is the Chairman of the International Glutamate Technical Committee (IGTC), a worldwide research organization having NGO status and carrying out or sponsoring extensive research on the efficacy, application and safety of glutamic acid and its salts especially as used in food. IGTC receives financial support from glutamate producers and users. Read the rebuttal by Dr Rogers HERE.

(rebuttal against Dr Rogers) January 2013 Nutrition & Metabolism 10(1):10
Project: The association of MSG and metabolic syndrome in human - HERE (pdf available)

Background & discussion
We appreciate the helpful comments by Dr. Rogers but with all due respect there are a number of problematic issues with his remarks on our most recent publication[1]. Firstly, while we agree that nutritional epidemiology is extremely challenging, particularly on the scale and population herein, we must emphasize that the data speak by themselves. Indeed, the rigorous statistical approach argues for the potentially detrimental effects of monosodium glutamate (MSG) on this target population. Second, our observation is supported by recent ani-mal data which, albeit with differences related to experimental models and dosage proportions, suggest a contribution of MSG to the worldwide epidemics of obesity, metabolic syndrome, diabetes and non-alcoholic steatohepatitis (NASH) [2-7]. It is well-established that obesity can be induced by an injection of MSG to newborn rodents. Third, we note that data from one of the studies considered as negative by Dr. Rogers [8] reported a larger waist circumference, a crucial parameter of the metabolic syndrome, and an elevated prevalence of central obesity associated with the highest quartile of MSG intake, in an analysis similar to our approach. Moreover,results of a cohort study from the same group also suggested the potentially negative impact of MSG on human health; MSG intake was associated with a significant increase in systolic and diastolic blood pressure [9].High blood pressure is one of the five criteria of ATPIII for the diagnosis of metabolic syndrome. Fourth, we agreed that there is inconsistency of the results of epidemiological studies on MSG intake and overweight which is always observed in epidemiological research field. So far, there are 3 studies showed the positive association and one study showed negative association of MSG intake and overweight... Finally, we note that none of the investigators in our paper has any industrial or personal disclosure...

Commentary on: "Further studies are necessary in order to conclude a causal association between the consumption of monosodium L-glutamate (MSG) and the prevalence of the metabolic syndrome in the rural Thai population" - HERE

Nutrition & Metabolism 10(1):13 · January 2013

Abstract
Sir, I read with considerable interest the epidemiological study by Insawang et al., which demonstrates an association between monosodium glutamate (MSG) intake and the prevalence of the Metabolic Syndrome in a rural Thai population (1). It is important to point out that Insawang et al. did not claim that MSG causes the Metabolic Syndrome, they did however concluded that "elevated dietary MSG consumption is significantly associated with having the Metabolic Syndrome and being overweight in a Thai rural population". The present commentary by Dr Rogers (2) concerning the research by Insawang et al. stresses throughout that there is no supporting evidence for a direct causal relationship between MSG intake and the prevalence of Metabolic Syndrome and overweight. The relevance of this oft-repeated statement is questionable since Insawang et al. never proposed a direct causal relationship between MSG intake and the Metabolic Syndrome. Although the authors of this epidemiological study are under no obligation to provide evidence for a causal relationship, a number of issues were raised which make interesting points for discussion.

Consumption of monosodium glutamate in relation to incidence of overweight in Chinese adults: China Health and Nutrition Survey (CHNS) HERE (full report)

Ka He, Shufa Du, Pengcheng Xun, Sangita Sharma, Huijun Wang, Fengying Zhai, Barry Popkin
The American Journal of Clinical Nutrition, Volume 93, Issue 6, June 2011, Pages 1328–1336

ABSTRACT
Background: It has been hypothesized that monosodium glutamate (MSG), a flavor enhancer, is positively associated with weight gain, which influences energy balance through the disruption of the hypothalamic signaling cascade of leptin action...

Conclusions: MSG consumption was positively, longitudinally associated with overweight development among apparently healthy Chinese adults. Additional studies are needed to elucidate mechanisms of action and to establish causal inference.

Rebuttal HERE (note: Authors: RGB and MS are employed by Ajinomoto USA Inc, a producer of MSG. LW is the executive director of The Glutamate Association.)!!

Monosodium glutamate is not associated with obesity or a greater prevalence of weight gain over 5 years: findings from the Jiangsu Nutrition Study of Chinese adults – comments by Samuels 

British Journal of Nutrition (2010), 104, 1729 - Letter to the Editor:

Important rebuttal by Adrienne Samuels - HERE (Original article she refers to - HERE)

Association of monosodium glutamate intake with overweight in Chinese adults: the INTERMAP Study - HERE (full report)

Ka He(1), Liancheng Zhao(2), Martha L Daviglus(3), Alan R Dyer(3), Linda Van Horn(3), Daniel Garside(3), Liguang Zhu(4), Dongshuang Guo(5), Yangfeng Wu(2), Beifan Zhou(2), Jeremiah Stamler(3), and for the INTERMAP Cooperative
1 Departments of Nutrition and Epidemiology, Schools of Public Health and Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
2 Department of Epidemiology, Fu Wai Hospital and Cardiovascular Institute, Chinese Academy of Medical Sciences, Beijing, China
3 Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
4 Guangxi Medical University, Nanning, China
5 Yu County Hospital, Shanxi, China
Obesity (Silver Spring). 2008 Aug; 16(8): 1875–1880.

In this study, our ability to examine the relation of MSG intake and obesity was limited by small number of persons (3%) with BMI ≥30.0. However, the partial correlation between MSG intake and BMI approached significance. Hence it is reasonable to infer that MSG intake is also associated with higher prevalence of obesity. This study is also limited by lack of data on leptin and adipsin concentrations. In addition, the INTERMAP findings are cross-sectional, but nevertheless unique; this topic has not been previously pursued in human population samples.

In conclusion, we found a positive relation of MSG intake to BMI that persisted with controlling for physical activity and total energy intake among apparently healthy Chinese adults. MSG intake was significantly related to prevalence of overweight. This study is of public health interest because MSG is increasingly used worldwide. This study also provides the first human data on this issue and raises a concern about MSG use and body weight in addition to allergenic effects. Further studies are needed to determine reproducibility of these findings, elucidate their etiopathogenetic pathway, and amass the evidence needed to assess whether the relation between MSG intake and body weight is causal.


Monosodium Glutamate Intolerance in Children - HERE

The New England Journal of Medicine 1975; 293:1204-1205 | December 4, 1975

This article has no abstract; the first 100 words appear below.

...To the Editor: It is established that some adults react adversely to monosodium glutamate and get "Chinese-restaurant syndrome."1 2 3 4 5 We have found that children seem to describe similar symptoms with almost the same degree of prevalence. The three children described below had symptoms that led them to be subjected to a variety of neurologic tests and were subsequently relieved of the symptoms when exogenous monosodium glutamate was removed from their diets.Case 1. A normal child who was begun on adult foods at six months of age began to have "shudder attacks" at about the same time. Attacks continued despite treatment...

Increased pain and muscle glutamate concentration after single ingestion of monosodium glutamate by myofascial temporomandibular disorders patients. HERE

Shimada A(1,2), Castrillon EE(3,4), Baad-Hansen L(3,4), Ghafouri B(5), Gerdle B(5), Wåhlén K(5), Ernberg M(4,6), Cairns BE(7), Svensson P(3,4).
1 Section of Orofacial Pain and Jaw Function, Department of Dentistry, Faculty of Health Sciences, Aarhus University, Denmark. akiko.shimada@odont.au.dk.
2 Scandinavian Center for Orofacial Neurosciences (SCON), Aarhus, Denmark. akiko.shimada@odont.au.dk.
3 Section of Orofacial Pain and Jaw Function, Department of Dentistry, Faculty of Health Sciences, Aarhus University, Denmark.
4 Scandinavian Center for Orofacial Neurosciences (SCON), Aarhus, Denmark.
5 Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, County Council of Östergötland, Linköping University, Sweden.
6 Section of Orofacial Pain and Jaw Function, Department of Dental Medicine, Karolinska Institute, Huddinge, Sweden.
7 Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, Canada.
Eur J Pain. 2016 Oct;20(9):1502-12.

BACKGROUND:
A randomized, double-blinded, placebo-controlled study was conducted to investigate if single monosodium glutamate (MSG) administration would elevate muscle/serum glutamate concentrations and affect muscle pain sensitivity in myofascial temporomandibular disorders (TMD) patients more than in healthy individuals.

...RESULTS:
In TMD, interstitial glutamate concentration was significantly greater after the MSG ingestion when compared with healthy controls. TMD reported a mean pain intensity of 2.8/10 at baseline, which significantly increased by 40% 30 min post MSG ingestion. At baseline, TMD showed lower PPTols in the masseter and trapezius, and higher diastolic blood pressure and heart rate than healthy controls. The MSG ingestion resulted in reports of headache by half of the TMD and healthy controls, respectively.

CONCLUSION:
These findings suggest that myofascial TMD patients may be particularly sensitive to the effects of ingested MSG. WHAT DOES THIS STUDY ADD?': Elevation of interstitial glutamate concentration in the masseter muscle caused by monosodium glutamate (MSG) ingestion was significantly greater in myofascial myofascial temporomandibular disorders (TMD) patients than healthy individuals. This elevation of interstitial glutamate concentration in the masseter muscle significantly increased the intensity of spontaneous pain in myofascial TMD patients.

Body Mass Index, Neighborhood Fast Food and Restaurant 
Concentration, and Car Ownership. HERE (pdf)

Sanae Inagami, Deborah A. Cohen, Arleen F. Brown, and Steven M. Asch
Journal of Urban Health: Bulletin of the New York Academy of Medicine, Vol. 86, No. 5

...A high concentration of local restaurants is associated with BMI. Car owners have higher BMIs than non-car owners; however, individuals who do not own cars and reside in areas with a high concentration of fast food outlets have higher BMIs than non-car owners who live in areas with no fast food outlets, approximately 12 lb more (p = 0.02) for an individual with a height of 5 ft. 5 in. Higher restaurant density is associated with higher BMI among local residents. The local fast food environment has a stronger association with BMI for local residents who do not have access to cars.

Monosodium l-glutamate-induced asthma - HERE

David H.Allen, M.B., Ph.D., John Delohery M.B., Gary Baker M.B., B.Sc.
From the Department of Thoracic Medicine, Royal North Shore Hospital, Sydney, Australia
Journal of Allergy and Clinical Immunology | Volume 80, Issue 4, October 1987, Pages 530-537

...Thirteen subjects reacted. Seven subjects (group 1) developed asthma and symptoms of the Chinese restaurant syndrome 1 to 2 hours after ingestion of MSG. Six subjects (group 2) did not develop symptoms of Chinese restaurant syndrome, and their asthma developed 6 to 12 hours after ingestion of MSG. These challenge studies confirm that MSG can provoke asthma. The reaction to MSG is dose dependent and may be delayed up to 12 hours, making recognition difficult for both patient and physician.

(as compared to another study HERE (Monosodium Glutamate Intake, Dietary Patterns and Asthma in Chinese Adults) "The data analysis was supported a research grant from International Glutamate Technical Committee." !!

Headache and mechanical sensitization of human pericranial muscles 
after repeated intake of monosodium glutamate (MSG) - HERE

Akiko Shimada(1), Brian E Cairns(2), Nynne Vad(1), Kathrine Ulriksen(1), Anne Marie Lynge Pedersen(3) Peter Svensson(1,4) and Lene Baad-Hansen(1)
1 Section of Clinical Oral Physiology, Department of Dentistry, Faculty of Health Sciences, Aarhus University, Vennelyst Boulevard 9, Aarhus C 8000, Denmark
2 Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
3 Section of Oral Medicine, Clinical Oral Physiology, Oral Pathology & Anatomy, Department of Odontology, Faculty of Health Sciences, University of Copenhagen, Nørre Allé 20, Copenhagen, 2200 København N, Denmark
4 MindLab, Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade 44, Aarhus C 8000, Denmark
The Journal of Headache and Pain. 2013; 14(1)

...Results
Headache occurred in 8/14 subjects during MSG and 2/14 during placebo (P = 0.041). Salivary glutamate concentrations on Day 5 were elevated significantly (P < 0.05). Pressure pain thresholds in masseter muscle were reduced by MSG on Day 2 and 5 (P < 0.05). Blood pressure was significantly elevated after MSG (P < 0.040).

Conclusion
In conclusion, MSG induced mechanical sensitization in masseter muscle and adverse effects such as headache and short-lasting blood pressure elevation for which tolerance did not develop over 5 days of MSG intake.

The sensitivity of male rat reproductive organs 
to monosodium glutamate. HERE (pdf available)

Sitthichai Iamsaard, Wannisa Sukhorum, Rarinthorn Samrid, Yimdee J, Kondo H., Pipatphong Kania, Chaisiwamongkol K, Wiphawi Hipkaeo, Duriya Fongmoon

...CONCLUSION: Testicular morphological changes, testosterone level, and sperm concentration were sensitive to high doses of MSG while the rate of AR was not affected. Therefore, the consumption of high dose MSG must be avoided because it may cause partial infertility in male. Copyright © 2014 by Academy of Sciences and Arts of Bosnia and Herzegovina.

Foreign body granuloma caused by monosodium glutamate after BCG vaccination - HERE

Yao-KunChiu MD(a) Chao-Cheng Huang MD(b), Jingyueh Jeng PhD(c), Jentaie Shiea PhD(c) Wei-Jen Chen MD(b)
a From the Department of Dermatology, Mennonite Christian Hospital, Hualien
b Department of Pathology, Chang-Gung Memorial Hospital, Kaohsiung, and Chang Gung University College of Medicine, Tao-Yuan
c Department of Chemistry, National Sun Yat-Sen University, Kaohsiung
Journal of the American Academy of Dermatology | Volume 55, Issue 2, Supplement, August 2006, Pages S1-S5

... Hence, MSG, the only composite of BCG vaccine except the bacillus, was believed to be responsible for the granulomatous foreign body reaction. ...

Brain Damage in Infant Mice following Oral Intake of 
Glutamate, Aspartate or Cysteine - HERE

JOHN W. OLNEY & OI-LAN HO
Nature volume 227, pages 609–611(1970)

Abstract
STRIKING degenerative changes in the infant mouse retina after subcutaneous treatment with monosodium glutamate (MSG) were reported by Lucas and Newhouse in 19571. Other studies (2–6) established that the process of retinal degeneration induced by MSG treatment is a remarkably acute and irreversible form of neuronal pathology. Recently it was found that a similar process of acute neuronal necrosis occurs in several regions of the infant mouse brain after subcutaneous treatment with MSG, and that animals treated with high doses in infancy tend to manifest obesity and neuroendocrine disturbances as adults (7,8). The arcuate nucleus of the hypothalamus is an area particularly vulnerable to glutamate induced damage in infant animals of several species (mice and rats (7), rabbits and chicks and the rhesus monkey (9). In mice, which have been studied more extensively for MSG induced disturbances than other species, the infant animal suffered hypothalamic damage from a relatively low subcutaneous dose (0.5 g/kg of body weight) (7).

Monosodium glutamate exposure during the neonatal period leads 
to cognitive deficits in adult Sprague-Dawley rats - HERE

Li Jin(a, j), 1, Lin, Li(b,c) 1, Guo-Yong Li(b,d) 1, Sha Liu(b,e) 1, Dan-Ju Luo(f), Qiong Feng(g), Dong-Sheng Sun(b), WeiWang(b), Jian-Jun Liu(h),QunWang(b), Dan Ke(b) Xi-FeiYang(h), Gong-Ping Liu(b,i)
a Department of Pathophysiology, Henan Medical College, Zhengzhou 451191, China
b Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, No. 13 Hangkong Road, Wuhan 430030, China
c Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jie-Fang Avenue, Wuhan 430030, China
d Department of Cardiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang,Chengdu 610041, China
e Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
f Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
g Department of Pathology, Wuhan Children's Hospital, Wuhan, 430016, China
h Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, No. 8 Longyuan Road, Nanshan District, Shenzhen 518055, China
i Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
j Henan Medical Key Laboratory of Cerebrodegenerative Disease, Henan Medical College, Zhengzhou 451191, China
Neuroscience Letters | Volume 682, 24 August 2018, Pages 39-44

...We found that neonatal MSG exposure induced hyperglycemia as well as Alzheimer-like learning and memory deficits with decreased dendritic spine density and hippocampal synaptic-related protein expression and increased phosphorylated tau levels in ∼3-month-old SD rats. Our results suggested that hyperglycemia probably causes cognitive impairment and Alzheimer-like neuropathological changes, which provide the experimental data connecting T2DM and AD.

NEPHROTOXIC EFFECT OF MSG (MONOSODIUM 
GLUTAMATE) IN THE CHICKEN - HERE (pdf)

TSUTOMU SHIMIZU, RITSUKO HIROHATA, YASUKO NOMURA, KAGEAKI AIBARA AND KOMEI MIYAKI
Department of Food Research, National Institute of Health, Shinagawa-ku, Tokyo 141, Japan
Japan. J. Med. Sci. Biol., 24, 271-279, 1971

...Two-day old chickens given MSG died of gout within a few days and showed higher mortality and
lesions severer than those given physiological saline, while none died nor was weakened among those receiving monopotassium glutamate. Very rapid development of kidney lesions and a large amount of urate deposits were the two main features resulting from MSG ingestion, and primary histological changes were tubular degeneration and tophi obstruction in collecting ducts. Even at half
concentration, MSG ingestion caused lobar atrophy in the kidney and some died of gout. Besides sodium toxicity, glutamate counterpart is suspected of contributing to uric acid synthesis.

Neurotoxic effects of glutamate on mouse area postrema - HERE

John W.Olney Vesela Rhee, Taisija De Gubareff
Department of Psychiatry, Washington University School of Medicine, St. Louis, Mo. U.S.A.
Brain Research | Volume 120, Issue 1, 14 January 1977, Pages 151-157

It is well established that glutamate (GLU), administered either orally or subcutaneously, rapidly destroys neurons in the inner retina and in several regions of brain. GLU neurotoxicity has been demonstrated in a number of species, including mice s,1°-12 , rats 2,5 , chicks 22, guinea pigs 16, hamsters 7,23 and monkeys 19 . GLU-induced damage to brain, studied most extensively in mice, was initially described 11 as involving certain mid-line structures bordering on the roof and floor of the third ventricle, viz., the medial preoptic and arcuate (ARH) nuclei of the hypothalamus and several neuronal populations lying in or near the subfornical and subcommissural organs...

Excitotoxic food additives: functional teratological aspects - HERE

John W.Olney
Departments of Psychiatry and Pathology, Washington University School of Medicine, St. Louis, Missouri, USA
Progress in Brain Research | Volume 73, 1988, Pages 283-294

Publisher Summary
This chapter reviews the information pertaining to the potential teratological consequences of excitotoxin exposure in early life. The chapter uses the term “teratological” in its broad sense to include adverse effects on the organism at any preadult stage of development. The putative excitatory neurotransmitters, glutamate (Glu) and aspartate (Asp), and several of their structural analogues, comprise a family of excitotoxic compounds, which are so called because of their potential for destroying central neurons by excessive stimulation of postsynaptic excitatory membrane receptors. Despite evidence from animal studies that the immature nervous system is much more vulnerable than the adult to excitotoxin-induced damage, Glu and other excitotoxins are used quite heavily worldwide as additives to foods ingested by infants and children. In molecular specificity studies, it was found that specific structural analogues of Glu known to share the neuroexcitatory properties of Glu reproduce its neurotoxic effects, that these analogues have a parallel order of potencies for their excitatory and toxic actions and that analogues lacking excitatory activity also lack neurotoxicity.

Components of hypothalamic obesity: bipiperidyl-mustard lesions add hyperphagia to monosodium glutamate-induced hyperinsulinemia - HERE

Andrew C.Scallet, John W.Olney
Department of Psychiatry, Washington University, School of Medicine, St. Louis, MO 63110 U.S.A.
Brain Research | Volume 374, Issue 2, 28 May 1986, Pages 380-384

...The combined treatment approach also represents the first rat model of hyperinsulinemic, hyperphagic obesity that can be entirely produced by systemic administration of neurotoxins.

Hypothalamic lesion induced by injection of monosodium glutamate 
in suckling period and subsequent development of obesity - HERE

Kazuhiko Tanaka, Morimi Shimada, Koji Nakao, Tomoichi Kusunoki
Department of Pediatrics, Kyoto Prefectural University of Medicine, Kyoto, Japan
Experimental Neurology | Volume 62, Issue 1, October 1978, Pages 191-199

...It is suggested that the development of overt obesity in mice treated with MSG is intimately related to damage in the ventromedial nucleus in addition to that in the arcuate nucleus...

Effects of Monosodium Glutamate in Ovaries of Female Sprague-Dawley Rats - HERE (pdf)

I. C. Oladipo(1), E. A. Adebayo(2) and O. M. Kuye(3)
1 Science Laboratory Technology Department, Ladoke Akintola University of Technology, P.M.B 4000, Ogbomoso, Oyo State, Nigeria
2 Department of Science Laboratory Technology, Ladoke Akintola University of Technology, Ogbomoso 210214, Oyo State, Nigeria
3 Department of Microbiology, University of Ibadan, Ibadan 200284, Oyo State, Nigeria
International Journal of Current Microbiology and Applied Sciences (2015) 4(5): 737-745

...These findings indicate that MSG induced considerable structural changes, including degenerated follicles, oocytes and medulla with vacuoles having congested blood vessels in the ovaries of Sprague-dawley rats; these changes are more severe at higher doses which may contribute to the causes of female infertility.

Monosodium glutamate induced histomorphometric changes 
in thyroid gland of adult wistar ratc- HERE (pdf)

Pooja Rani(1), Kamlesh Khatri(2), Renu Chauhan(1)
1 University College of Medical Sciences and GTB Hospital, Delhi-110095, India.
2 School of Medical Sciences and Research, Sharda Medical University, Greater Noida, U.P., India.
Journal of Medical & Allied Sciences 2013; 3(2): 67-71

...The results of the present study showed a significant increase in the body weight of the MSG treated animals, although these animals consumed less food than the controls. A significant increase in the size of the follicles accompanied by an increase in the mean height and area of the follicular cells and decreased colloid in some of the follicles was observed, pointing towards an increase in thyroid gland activity.

Association of monosodium glutamate intake with overweight
 in Chinese adults: the INTERMAP Study - HERE


Ka He(1), Liancheng Zhao(2), Martha L Daviglus(3), Alan R Dyer(3), Linda Van Horn(3), Daniel Garside(3), Liguang Zhu(4), Dongshuang Guo(5), Yangfeng Wu(2), Beifan Zhou(2), Jeremiah Stamler(3) and for the INTERMAP Cooperative Research Group
Obesity (Silver Spring). 2008 Aug; 16(8): 1875–1880.

...This research provides human data that MSG intake may be associated with increased risk of overweight independent of physical activity and total energy intake...

Obese Women Have Lower Monosodium Glutamate Taste Sensitivity and Prefer Higher Concentrations Than Do Normal-weight Women - HERE

M. Yanina Pepino, Susana Finkbeiner, Gary K. Beauchamp and Julie A. Mennella
Obesity (Silver Spring). 2010 May; 18(5): 959–965.

... Taken together, these data suggest that body weight is related to some components of umami taste and that different mechanisms are involved in the perception of threshold and suprathreshold MSG concentrations.

Effects of monosodium glutamate on somatic development, 
obesity and activity in the mouse - HERE

William J.Pizzi, June E.Barnhart
Department of Psychology, Northeastern Illinois University, Chicago, IL 60625, USA
Pharmacology Biochemistry and Behavior | Volume 5, Issue 5, November 1976, Pages 551-557

Abstract
Neonatal mice 1 and 5 days of age and older mice 25 days of age were injected with an increasing dose of monosodium glutamate (MSG) for a ten-day period and observed for at least 150 days. Both male and female animals in the 1- and 5-day age group treated with MSG showed large increases in weight over controls along with a shortened body length. The MSG group also showed decreases in locomotor and explaratory behavior. The 25-day animals took much longer to show effects or failed to show any effects, indicating that the MSG-induced changes studied are age dependent. Possible methodological considerations accounting for conflicting reports in the MSG literature are discussed in light of the present findings.

Toxicity of hypercaloric diet and monosodium glutamate: 
oxidative stress and metabolic shifting in hepatic tissue - HERE

Yeda S.Diniz(a), Ana A.H.Fernandes(b) Kleber E.Campos(b) Fernanda Mani(b), Bartolomé O.Ribas(c) Ethel L.B.Novelli(b)
a Post Graduation Course Department of Clinical and Cardiology, Faculty of Medicine, UNESP, Botucatu, São Paulo, Brazil
b Department of Chemistry and Biochemistry, Institute of Biological Sciences, University of São Paulo State, UNESP, Botucatu, São Paulo, Brazil
c Department of Toxicology, Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Madrid, Spain
Food and Chemical Toxicology | Volume 42, Issue 2, February 2004, Pages 313-319

... Therefore, the hepatic glucose metabolic shifting induced by HD intake and MSG administration were associated with oxidative stress in hepatic tissue. ...

Vasospasm Contributes to Monosodium Glutamate‐lnduced Headache - HERE

James E Merritt & Patricia Bell Williams
Article in Headache The Journal of Head and Face Pain 30(9):575 - 580 · May 2005

...These results demonstrate a direct effect of glutamate on peripheral arterial tone. Dietary consumption of large quantities of MSG may represent a serious health hazard to certain individuals with pre-existing vascular disease...

Sensory and autonomic nerve changes in the monosodium 
glutamate‐treated rat: a model of type II diabetes - HERE

John F. B. Morrison, Safa Shehab, Rajan Sheen, Subramanian Dhanasekaran, Mohammed Shaffiullah, Eric Mensah‐Brown
Experimental Physiology, Volume 93, Issue 2 -14 November 2007

Abstract
Rats that had been injected with monosodium glutamate (MSG) neonatally were studied for up to 70 weeks and compared with age‐matched control rats to study changes in glucose tolerance and in sympathetic and sensory nerves. At 61 and 65 weeks of age, there were significant differences in glucose tolerance between the MSG and control groups, and the MSG group had raised fasting blood glucose. These changes were not associated with changes in the number of β‐cells in the islets of Langerhans. In addition, the diabetic MSG‐treated rats had central obesity and cataracts. Hypoalgesia to thermal stimuli was present in MSG‐treated rats as early as 6 weeks and persisted at 70 weeks. However, no differences were observed in the distribution of substance P, the neurokinin‐1 receptor or calcitonin gene‐related peptide in the dorsal horn of L3–L5 at this age (70 weeks). Diabetic MSG‐treated animals at 65 and 70 weeks of age had significantly reduced noradrenaline concentrations in the heart, tail artery and ileum, while concentrations in the adrenal gland and corpus cavernosum were significantly increased. There was also a significant increase in adrenal adrenaline, dopamine and serotonin, largely attributable to changes in weight of the adrenal gland in the MSG‐treated animals. The results indicate that MSG‐treated animals develop a form of type II diabetes by about 60 weeks of age, and that there are significant changes in amine levels in various tissues associated with these developments.

Monosodium glutamate (MSG) alters protein, vasopressin, and 
oxytocin in microdissected hypothalamic areas in newborn and adult rats - HERE

Franz Schubert, Jack M.George, M.Bhaskar Rao
Department of Medicine, Ohio State University Hospital 410 West Tenth Avenue, Columbus, Ohio 43210, USA
Life Sciences | Volume 26, Issue 8, 25 February 1980, Pages 651-656

Abstract
Monosodium glutamate (MSG) was removed from baby food products in 1969 following reports that MSG produced destructive lesions in the hypothalamus of newborn animals. We have given MSG to 10-day old and adult rats in doses previously used in histological studies and have found effects on protein, vasopressin, and oxytocin content of microdissected hypothalamic areas. Protein was significantly reduced in arcuate and median eminence areas of 10-day old rats and in arcuate and suprachiasmatic nuclei of adults. Hormone content was increased or decreased in various hypothalamic nuclei in both 10-day old and adult rats. Our results demonstrate a biochemical counterpart to previously described histologic lesions and indicate that adults are not immune to brain effects of MSG.

Locomotor and learning deficits in adult rats exposed to 
monosodium-l-glutamate during early life - HERE

M.Mohd Ali(a), M Bawari(b), U.KMisra(b), G.N Babu(b)
a Neurotoxicology Section, Industrial Toxicology Research Centre, P.O. Box 80, M.G. Marg, Lucknow 226 001, India
b Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Rae Bareilly Road, Lucknow 226 014, India
Neuroscience Letters | Volume 284, Issues 1–2, 21 April 2000, Pages 57-60

Neonatal administration of neurotoxic doses of monosodium-l-glutamate (MSG) to rats causes neuronal necrosis of the hypothalamus along with behavioral abnormalities. In the present study the behavioral effects in rats treated with subneurotoxic doses of MSG (2 mg/g, p.o., for 10 days) at the weaned stage were investigated at day 90 post-dosing. The MSG-treated rats did not show significant changes in any of the components of spontaneous locomotor activity but, after apomorphine challenge, marked decreases in the distance travelled, ambulatory and stereotypic times, and the number of stereotypic movements with an increase in the resting time were observed. Significant decrease in the active avoidance learning performance was observed in the MSG-treated rats in the learning (acquisition) phase without any changes in the extinction and relearning phases. The results indicate that exposure to MSG in early life in rats could lead to subtle behavioral aberrations in late adulthood.

Dose dependent development of diabetes mellitus and non-alcoholic steatohepatitis in monosodium glutamate-induced obese mice. HERE

Sasaki Y1, Suzuki W, Shimada T, Iizuka S, Nakamura S, Nagata M, Fujimoto M, Tsuneyama K, Hokao R, Miyamoto K, Aburada M.
1 Department of Clinical Pharmacy, Graduate School of Natural Science and Technology, and Department of Hospital Pharmacy, School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Japan.
Life Sci. 2009 Sep 23;85(13-14):490-8.

Abstract...KEY FINDINGS:
In all the MSG treatment groups, severe obesity developed by 29 weeks of age. The onset of diabetes mellitus and liver lesions (resembling those of human NAFLD/NASH) were observed before 54 weeks of age. The obesity, diabetes mellitus and liver lesions were most severe in the 4 mg/g x 1 group. In the 4 mg/g x 5 group, increases in body weight and body length were inhibited by MSG's severe toxicity.

SIGNIFICANCE:
A single 4 mg/g dose of MSG is the most suitable as the obese model and induces not only severe obesity and diabetes mellitus, but also liver changes resembling human NAFLD/NASH. A small amount of MSG in the newborn develops obesity and the other complications without hyperphagia after a long term.

Monosodium glutamate induced convulsions in rats: Influence 
of route of administration, temperature and age - HERE

R. Peñafiel(1) A. Cremades(2) F. Monserrat, L. Puelles(3)
1.Departments of Biochemistry and Molecular BiologyFaculty of Medicine, University of MurciaMurciaSpain
2.Departments of PharmacologyFaculty of Medicine, University of MurciaMurciaSpain
3.Departments of AnatomyFaculty of Medicine, University of MurciaMurciaSpain
Amino Acids | February 1991, Volume 1, Issue 1, pp 81–89

Summary
Treatment of developing rats with monosodium glutamate (MSG) produces an increase of glutamate levels in the brain, being this elevation dependent on both route of administration and animal's age. The capacity of exogenous MSG to induce convulsions seems to be related to the rate of glutamate elevation in the brain, rather than to the absolute value of glutamate concentration reached. Short exposure of MSG-treated rats to moderate hyperthermia potentiated the convulsive incidence and extended the brain damage to areas not affected by treatment with MSG alone, suggesting that the synergic effect of hyperthermia on glutamate neurotoxicity may be related to an increase in the permeability of the blood-brain barrier in the hyperthermic developing rats.

Monosodium glutamate-related orofacial granulomatosis: Review and case report - HERE

Anthony J.Oliver BDS, MDSc(Registrar) (a)
Alison M.Rich BDS, MDSc(FRACDS, Senior Lecturer in Oral Medicine) (b)
Peter C.Reade MDS, PhD, MDSc(FDSRCS, FRCPath, Professor and Head)(c)
George A.Varigos MB, BS, PhD(FACD, Head) (d,e)
Bryan G.Radden BDSc, PhD, MDSc (FDSRCS, FRCPath, Reader in Oral Pathology) (f)

a Section of Oral Medicine and Oral Surgery, School of Dental Science, University of Melbourne. Melbourne, Victoria, Australia
b Section of Oral Medicine and Oral Surgery, School of Dental Science, University of Melbourne. Melbourne, Victoria, Australia
c Section of Oral Medicine and Oral Surgery, School of Dental Science, University of Melbourne. Melbourne, Victoria, Australia
d Department of Dermatology, The Royal Melbourne Hospital Melbourne, Victoria, Australia
e The Royal Children's Hospital. Melbourne, Victoria, Australia
f Section of Oral Medicine and Oral Surgery, School of Dental Science, University of Melbourne. Melbourne, Victoria, Australia
Oral Surgery, Oral Medicine, Oral Pathology | Volume 71, Issue 5, May 1991, Pages 560-564

Abstract
A case is reported in a 15-year-old white girl who had a swollen lower fa̧ce and lips; a diagnosis of orofacial granulomatosis was made. It was suspected that her condition had an allergic basis because an increase in clinical signs and symptoms was shown to be related to the food additive monosodium glutamate. Treatment with a restricted diet resulted in resolution of the facial swelling.

Neonatal exposure to monosodium l-glutamate induces loss of neurons and cytoarchitectural alterations in hippocampal CA1 pyramidal neurons of adult rats - HERE

CarlosBeas-Zárate(a), Marı́a Isabel Pérez-Vega(b) Ignacio González-Burgos(b)
a Laboratorio de Neurobiologı́a Celular y Molecular, CIBO, IMSS/Departamento de Biologı́a Celular y Molecular, CUCBA, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
b Laboratorio de Psicobiologı́a, División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social (IMSS), A.P. 7-70, C.P. 58261, Morelia, Michoacán, Mexico
Brain Research | Volume 952, Issue 2, 18 October 2002, Pages 275-281

... These results strongly suggest the occurrence of cell death and also show some cytoarchitectural modifications in the surviving neurons. These could lead to functional alterations in the hippocampal integrative activity, due to an early cytoexcitotoxic effect of monosodium glutamate...

The toxic effects of glutamate and related compounds in the retina and the brain. - HERE

Olney JW (1).
1 Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110.
Retina. 1982;2(4):341-59.

Abstract
This paper has reviewed information pertaining to an interesting group of amino acids--glutamate, aspartate, and certain of their structural analogs, some of which are neurotransmitter candidates, and all of which have both neuroexcitatory and neurotoxic activities. Evidence for the excitotoxic concept, which holds that an excitatory and possibly synapse-related mechanism underlies the neurotoxicity of these compounds, is presented. Unlike a number of environmental neurotoxicants which induce toxic changes primarily in axons, these agents attack the dendrosomal portions of the neuron, which has led to their use as "axon-sparing" lesioning agents. When administered either systemically or by direct microinjection into the CNS, they delete intrinsic neurons from infiltrated regions without disturbing axons that are passing through or terminating therein. They are potentially useful tools, therefore, for studying anatomical pathways and structure-function relations in the CNS. The basis for their use as systemic investigational tools--that they have access from blood to the retina and specialized regions of brain, the circumventricular organs--is also the basis for considering them potentially hazardous for use as food additives or drugs. Ways in which the consumer may be exposed to these agents are considered and relevant mechanisms of risk are discussed.

Behavioral suppression induced by oral administration 
of monosodium L-glutamate in rats - HERE

Sakutaro Tadokoro,Yoichiro Higuchi, Hisashi Kuribara, Kiyoko Okuizumi
Behavior Research Institute, School of Medicine, Gunma University, Maebashi 371, Japan
Pharmacology Biochemistry and Behavior | Volume 2, Issue 5, September–October 1974, Pages 619-625

...The exact nature of the toxic hazards of MSG remain obscure, but nevertheless present indications are that one should refrain from adding a large dose of MSG to food...

Locomotor and learning deficits in adult rats exposed to 
monosodium-l-glutamate during early life - HERE

M.Mohd Ali(a), M Bawari(b), U.KMisra(b), G.N Babu(b)
a Neurotoxicology Section, Industrial Toxicology Research Centre, P.O. Box 80, M.G. Marg, Lucknow 226 001, India
b Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Rae Bareilly Road, Lucknow 226 014, India
Neuroscience Letters | Volume 284, Issues 1–2, 21 April 2000, Pages 57-60

Neonatal administration of neurotoxic doses of monosodium-l-glutamate (MSG) to rats causes neuronal necrosis of the hypothalamus along with behavioral abnormalities. In the present study the behavioral effects in rats treated with subneurotoxic doses of MSG (2 mg/g, p.o., for 10 days) at the weaned stage were investigated at day 90 post-dosing. The MSG-treated rats did not show significant changes in any of the components of spontaneous locomotor activity but, after apomorphine challenge, marked decreases in the distance travelled, ambulatory and stereotypic times, and the number of stereotypic movements with an increase in the resting time were observed. Significant decrease in the active avoidance learning performance was observed in the MSG-treated rats in the learning (acquisition) phase without any changes in the extinction and relearning phases. The results indicate that exposure to MSG in early life in rats could lead to subtle behavioral aberrations in late adulthood.

Deficit in hippocampal long-term potentiation in monosodium glutamate-treated rats. HERE

Sanabria ER(1), Pereira MF, Dolnikoff MS, Andrade IS, Ferreira AT, Cavalheiro EA, Fernandes MJ.
1 Departamento de Neurologia e Neurocirurgia, Disciplina de Neurologia Experimental, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, SP, Brazil.
Brain Res Bull. 2002 Oct 15;59(1):47-51.

Abstract
Rats subjected to monosodium glutamate (MSG) administration during the neonatal period present chronic neuroendocrine dysfunction associated with marked cognitive deficits...
...These findings indicate that MSG-treated rats display a chronic impairment of CA1 synaptic plasticity.

Learned taste aversions induced by high doses of monosodium L-glutamate - HERE

John R.Vogel, Beth A.Nathan
Central Nervous System Section, Wm. H. Rorer, Inc., Fort Washington, PA 19034, USA
Pharmacology Biochemistry and Behavior | Volume 3, Issue 5, September–October 1975, Pages 935-937

Abstract
Learned taste aversions, as measured by increased time to complete 100 licks of a sweetened condensed milk solution, were demonstrated by laboratory rats 4 days after consumption of the milk solution paired with high oral doses of monosodium l-glutamate (MSG). The hesitancy of the rats to consume milk on the test session cannot be simply attributed to direct action of the drug on motivation (e.g., hunger) or to drug debilitation. MSG has been reported to occasionally cause aversive effects in humans (Chinese restaurant syndrome), and the present experiments demonstrate that the effects of MSG are aversive to laboratory rats as well.

Differential effects of repetitive oral administration of monosodium glutamate 
on interstitial glutamate concentration and muscle pain sensitivity - HERE

Akiko ShimadaD.D.S., Ph.D.(a,b) LeneBaad-Hansen Ph.D.(a,b), Eduardo Castrillon Ph.D(a,b), Bijar Ghafouri Ph.D(c,d), Niclas Stensson M.Sc.(c), Björn GerdlePh.D.(c), Malin Ernberg Ph.D.(b,e), Brian Cairns Ph.D.(f), Peter Svensson Ph.D.(a,b)

a  Section of Clinical Oral Physiology, Department of Dentistry, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
b  Scandinavian Center for Orofacial Neurosciences (SCON)
c  Department of Medical and Health Sciences, Rehabilitation Medicine, Faculty of Health Sciences, Linköping University & Pain and Rehabilitation Centre, County Council of Östergötland, Linköping, Sweden
d  Department of Clinical and Experimental Medicine, Occupational and Environmental Medicine, Faculty of Health Sciences, Linköping University and Centre of Occupational and Environmental Medicine, County Council of Östergötland, Linköping, Sweden
e  Section of Orofacial Pain and Jaw Function, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
f  Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
Nutrition | Volume 31, Issue 2, February 2015, Pages 315-323

...Results... A statistically significant increase in systolic and diastolic blood pressures after MSG administration was observed, as well as a significantly higher frequency of reports of nausea and headache in the MSG group.

Monosodium glutamate is related to a higher increase in blood pressure over 
5 years: findings from the Jiangsu Nutrition Study of Chinese adults. HERE

Shi Z(1), Yuan B, Taylor AW, Dai Y, Pan X, Gill TK, Wittert GA.

1 Department of Nutrition and Foodborne isease Prevention, Jiangsu Provincial Centre for Disease Control and Prevention, 172 Jiangsu Road, Nanjing 210009, China.
J Hypertens. 2011 May;29(5):846-53.

...RESULTS:
MSG intake was associated with a significant increase in SBP and DBP. A strong sex interaction was observed in relation to SBP change. Women with high MSG intake were more likely to have increased SBP and DBP. Total glutamate intake was also positively associated with an increase in SBP. In those chronically taking antihypertensive medications, there was a strong association between MSG intake and an increase in DBP.

CONCLUSION:
MSG intake may have independent BP-increasing effects, especially among women and those taking hypertension medications at baseline and follow-up.

Alterations in immunoreactive somatostatin levels in hypothalamic and gastroenteropancreatic tissue as a consequence of neonatal treatment with monosodium glutamate. HERE

DePaolo LV, Steger RW.
Proc Soc Exp Biol Med. 1985 Mar;178(3):419-25.

Abstract
... These results show that neonatal MSG treatment not only affects IRS levels in the hypothalamus and blood as previously reported, but in parts of the GEP system as well. Further, effects on hypothalamic IRS levels are opposite to those on GEP IRS levels. The significance of these findings may relate to the altered metabolic state of these animals as a consequence of perturbations in the secretion of other hormones from the hypothalamus, anterior pituitary gland, and possibly the GEP system.
Prenatal monosodium glutamate causes long-lasting 
cholinergic and adrenergic changes in various brain regions. - HERE

Frieder B, Grimm VE.
J Neurochem. 1987 May;48(5):1359-65.

Abstract
Prenatal monosodium glutamate (MSG) given through the mother's diet was found previously to cause behavioral changes in the offspring, including learning disabilities. In the present study, neurochemical parameters were measured in the brains of prenatally exposed rats at various ages throughout development up to adulthood. At 15 days of age, choline uptake and choline acetyltransferase (ChAT) activity in the frontal cortex were significantly reduced (by 80 and 25%, respectively) in MSG-exposed animals, whereas the same cholinergic parameters in hippocampus were not changed. During later development, choline uptake gradually increased, until in adulthood it became significantly higher in MSG-exposed animals than in the controls. This enhancement was found in both males and females. Our previous study showed that only the male offspring were learning disabled. Choline uptake and ChAT activity were enhanced in the hippocampus of adult male animals. Norepinephrine (NE) uptake was reduced (by 25%) in the frontal cortex of males only. There was no change in NE uptake in the hypothalamus.

Changes in open-field activity and novelty-seeking behavior in 
periadolescent rats neonatally treated with monosodium glutamate - HERE

P. Kiss, D. Hauser, A. Tamas, A. Lubics, B. Racz, Z. Horvath, J. Farkas, F. Zimmermann, A. Stepien, I. Lengvari, D. Reglodi
Neurotoxicity Research | June 2007

Astract
Monosodium glutamate (MSG) treatment of neonatal rodents leads to degeneration of the neurons in the arcuate nucleus, inner retinal layers and various other brain areas. It also causes various changes in the motor activity, sensory performance and learning abilities. We have previously shown that MSG treatment delays the appearance of some reflexes during neurobehavioral development and leads to temporary changes in reflex performance and motor coordination. Investigation of novelty-seeking behavior is of growing importance for its relationship with sensitivity to psychomotor stimulants. Perinatal administration of numerous toxic agents has been shown to influence novelty-seeking behavior in rats, but little is known about the influence of neonatal MSG treatment on the novelty-seeking behavior. The aim of the present study was to compare changes in locomotor, spontaneous exploratory and novelty-seeking behavior in periadolescent rats neonatally treated with MSG...

... We found that the behavioral pattern of MSG-treated rats was the opposite in all tested signs in the novelty exploration test compared to control pups. In summary, our present study shows that neonatal MSG treatment leads to early temporary changes in the locomotor activity followed by hypoactivity at 2 months of age. Furthermore, MSG-treated rats show a markedly disturbed novelty-seeking behavior represented by altered activity when subjected to a novel object. ...

Interactive effects of neonatal exposure to monosodium glutamate 
and aspartame on glucose homeostasis - HERE

Kate S Collison, Nadine J Makhoul, Marya Z Zaidi, Rana Al-Rabiah, Angela Inglis, Bernard L Andres, Rosario Ubungen, Mohammed Shoukri, and Futwan A Al-Mohanna
Nutrition & Metabolism (Lond). 2012; 9: 58.

...Conclusions
Aspartame exposure may promote hyperglycemia and insulin intolerance. MSG may interact with aspartame to further impair glucose homeostasis. This is the first study to ascertain the hyperglycemic effects of chronic exposure to a combination of these commonly consumed food additives; however these observations are limited to a C57BL/6 J mouse model. Caution should be applied in extrapolating these findings to other species.

Study of lysosomal changes in rat pancreas after ingesting monosodium L-glutamate. HERE

Lee KT(1), Sheen PC
1. Department of Surgery, Kaohsiung Medical College Hospital, Taiwan, R.O.C.
Pancreas, 01 May 1994, 9(3):304-308

... The ultrastructural changes in pancreatic acinar cells revealed an increase in the number and size of autophagic vacuoles and various sizes of myelin figures in the cytoplasm and interstitial space. Dilatation of rough endoplasmic reticulum, swollen mitochondria, and altered zymogen granules were occasionally found. These changes occurred most often in Group I rats, which ingested 1% MSG for 1 month. The changes became less prominent as the dose of MSG administered was lessened. A reaction product of ACPase could also be seen in autophagic vacuoles in Group I rats. Regarding quantitative measurement, the serum level of ACPase for Group I rats was markedly higher than that of the controls and was statistically significant (20.52 +/- 4.92 vs. 12.62 +/- 4.13 U/L; p < 0.05)

Effects of pituitary adenylate cyclase activating polypeptide and its fragments on retinal degeneration induced by neonatal monosodium glutamate treatment. - HERE

Atlasz T(1), Szabadfi K, Reglodi D, Kiss P, Tamás A, Tóth G, Molnár A, Szabó K, Gábriel R.
1 Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.
Ann N Y
Acad Sci. 2009 Apr;1163:348-52.

Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a member of the growing family of neurotrophic and neuroprotective factors playing important roles during neuronal development and protection against different types of injuries, such as Parkinson's disease, excitotoxicity, and ischemia. As shown with other neuronal tissues, we provide evidence that PACAP is protective in the retina against toxic injury induced by monosodium glutamate (MSG) in vivo. The need for characterization of its fragments and analogues has recently been emphasized. The aim of the present study was to compare the effects of the physiologically occurring fragments PACAP1-38 and 1-27 and the widely used antagonists (PACAP6-38 and 6-27) in retinal degeneration induced by MSG in neonatal pups. Histological analysis showed that MSG treatment caused the degeneration of the entire inner plexiform layer and the inner nuclear and ganglion cell layers seemed fused. The total thickness of the retina was significantly reduced. Similar and substantial protective effects could be observed after three treatments with PACAP1-38 and 1-27, while MSG toxicity was further aggravated by the PACAP antagonists PACAP6-38 and 6-27. Glutamate-induced toxicity is known to play a role in several retinal pathologies. Our results provide further evidence for the effectiveness of the endogenously present PACAP forms in counteracting retinotoxicity and call for further studies leading to the discovery of potent analogues that could be used in human ophthalmic diseases.

Monosodium glutamate neonatal intoxication associated with obesity in adult stage is characterized by chronic inflammation and increased mRNA expression of peroxisome proliferator-activated receptors in mice. - HERE

Roman-Ramos R(1), Almanza-Perez JC, Garcia-Macedo R, Blancas-Flores G, Fortis-Barrera A, Jasso EI, Garcia-Lorenzana M, Campos-Sepulveda AE, Cruz M, Alarcon-Aguilar FJ.

1 Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University of Iztapalapa, DF, Mexico.
Basic Clin Pharmacol Toxicol. 2011 Jun;108(6):406-13.

Abstract
The monosodium glutamate (MSG) neonatal administration in mice provides a model of obesity with impaired glucose tolerance (IGT) and insulin resistance. However, the inflammatory profile of cytokines produced from fat tissue and its relationship to the metabolic dysfunction induced by MSG have not yet been revealed. The aim of this study was to establish the inflammatory profile attributed to MSG by measuring the expression of adipokines in visceral fat and serum of 19-week-old mice as well as the peroxisome proliferator-activated receptors alpha and gamma (PPARα and γ). Some metabolic and biochemical parameters were also quantified. The MSG increased mRNA expression of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNFα), resistin and leptin, but adiponectin did not exhibit any changes. In addition, impaired glucose tolerance, increased levels of insulin, resistin and leptin were observed in serum. Both PPARα and PPARγ were activated in MSG-induced obese mice, which might explain its inflammatory profile. However, liver transaminases were severely depressed, indicating that MSG may also induce liver injury, contributing to inflammation. The MSG neonatal neuro-intoxication in mice may thus provide a model of obesity and inflammation characterized by the dual activation of PPARα and PPARγ, which might offer new insights into the mechanism of inflammatory diabetes in obesity leading to steatohepatitis, as well as a suitable model to study the role of new therapeutic agents to prevent or reduce insulin resistance, the inflammatory state and liver steatosis.

© 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.
Prenatal monosodium glutamate (MSG) treatment given through
 the mother's diet causes behavioral deficits in rat offspring. HERE

Frieder B, Grimm VE.
Int J Neurosci. 1984 Apr;23(2):117-26.

The present study reports various developmental and behavioral changes in the offspring of rat dams that received monosodium glutamate (MSG) in the drinking water all through the second and third trimesters of pregnancy. Three main effects were observed in the MSG exposed offspring: (1) juvenile obesity; (2) reduced general activity levels; (3) a specific type of learning disability in discrimination learning involving choice between simultaneously present positive and negative stimuli.

Neurotoxicity of monosodium-l-glutamate in pregnant and fetal rats - HERE

L. Tóth 1.Department of AnatomyUniversity Medical SchoolSzegedHungary
S. Karcsu 2.Endocrine Unit, First Department of MedicineUniversity Medical SchoolSzegedHungary
J. Feledi 3.Department of Anaesthesiology and Intensive TherapyUniversity Medical SchoolSzegedHungary
G.W. Kreutzberg 4.Department of NeuromorphologyMax-Planck-Institute for PsychiatryMartinsried bei MünchenFederal Republic of Germany
Acta Neuropathologica | January 1987, Volume 75, Issue 1, pp 16–22

Summary

Monosodium-l-glutamate given subcutaneously to pregnant rats caused acute necrosis of the acetylcholinesterase-positive neurons in the area postrema. The same effect has been observed in the area postrema of fetal rats. The process of neuronal cell death and the elimination of debris by microglia cells proved to be similar in pregnant animals and in their fetuses. However, embryonal neurons were more sensitive to glutamate as judged by the rapidity of the process and the dose-response relationship. These observations raise the possibility of transplacental poisoning in human fetuses after the consumption of glutamate-rich food by the mother.

Excitotoxicity Triggered by Neonatal Monosodium Glutamate Treatment 
and Blood–Brain Barrier Function - HERE

Graciela Gudiño-Cabrera (a), Monica E.Ureña-Guerrero (a), Martha C.Rivera-Cervantes(a), Alfredo I.Feria-Velasco (a) CarlosBeas-Záratea (b)
a Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, Jalisco, México
b División de Neurociencias, CIBO, IMSS, Guadalajara, Jalisco, México
Received 10 November 2014,

It is likely that monosodium glutamate (MSG) is the excitotoxin that has been most commonly employed to characterize the process of excitotoxicity and to improve understanding of the ways that this process is related to several pathological conditions of the central nervous system. Excitotoxicity triggered by neonatal MSG treatment produces a significant pathophysiological impact on adulthood, which could be due to modifications in the blood–brain barrier (BBB) permeability and vice versa. This mini-review analyzes this topic through brief descriptions about excitotoxicity, BBB structure and function, role of the BBB in the regulation of Glu extracellular levels, conditions that promote breakdown of the BBB, and modifications induced by neonatal MSG treatment that could alter the behavior of the BBB. In conclusion, additional studies to better characterize the effects of neonatal MSG treatment on excitatory amino acids transporters, ionic exchangers, and efflux transporters, as well as the role of the signaling pathways mediated by erythropoietin and vascular endothelial growth factor in the cellular elements of the BBB, should be performed to identify the mechanisms underlying the increase in neurovascular permeability associated with excitotoxicity observed in several diseases and studied using neonatal MSG treatment.

Effect of systemic monosodium glutamate (MSG) on headache 
and pericranial muscle sensitivity. HERE

Baad-Hansen L (1), Cairns B, Ernberg M, Svensson P.
1. Department of Clinical Oral Physiology, School of Dentistry, University of Aarhus, Aarhus, Denmark.
Cephalalgia. 2010 Jan;30(1):68-76.

Abstract
We conducted a double-blinded, placebo-controlled, crossover study to investigate the occurrence of adverse effects such as headache as well as pain and mechanical sensitivity in pericranial muscles after oral administration of monosodium glutamate (MSG). In three sessions, 14 healthy men drank sugar-free soda that contained either MSG (75 or 150 mg/kg) or NaCl (24 mg/kg, placebo). Plasma glutamate level, pain, pressure pain thresholds and tolerance levels, blood pressure (BP), heart rate and reported adverse effects were assessed for 2 h. No muscle pain or robust changes in mechanical sensitivity were detected, but there was a significant increase in reports of headache and subjectively reported pericranial muscle tenderness after MSG. Systolic BP was elevated in the high MSG session compared with low MSG and placebo. These findings add new information to the concept of MSG headache and craniofacial pain sensitivity.

Testicular protective and antioxidant effects of selenium nanoparticles on Monosodium glutamate-induced testicular structure alterations in male mice. HERE

Hamza RZ(1,2), Diab AEA(2).
1 Biology Department, Faculty of Science, Taif University, Taif, Saudi Arabia.2 Zoology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
Toxicol Rep. 2020 Jan 27;7:254-260.

BACKGROUND:
Selenium has a protective antioxidant effect on several tissues. Monosodium glutamate (MSG), MSG has been known as flavor enhancer that influences reversely on male reproductive systems and having a number of side effects, including reproductive toxicity. 

OBJECTIVES:
The current study aims to evaluate the possible ameliorative functions of selenium nanoparticles (SeNPs) on MSG-induced reproductive toxicity.

Protective effects of alpha stone on monosodium glutamate-induced 
uterine hyperplasia in female wistar rats - HERE (pdf available)

Olubukola T.Oyebode, Martin E.Obiekwe, Olufunso O.Olorunsogo
Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Nigeria
Journal of Ayurveda and Integrative Medicine | 22 November 2019

...Results
Administration of MSG for 14 days resulted heavy deposits of collagen connective tissue within the myometrium layers of the uteri. ASD significantly (p < 0.05) reduced fibroblast cell count in MSG-treated animals and also protected against MSG-induced damage observed in the myometrium of the uteri and ovaries of the animals. Significant increases (p < 0.05) in levels of total protein; triglycerides, progesterone, cholesterol and estrogen in the MSG-treated animals were ameliorated following administration of ASD.

Conclusion
These findings suggest that ASD contains bioactive agents which reversed MSG-induced uterine hyperplasia. It may therefore be useful in reducing the proliferation of fibroblast cells and managing other symptoms associated with uterine myoma.

Effect of Emblica officinalis (Amla) on Monosodium Glutamate (MSG) 
Induced Uterine Fibroids in Wistar Rats - HERE

Inshah Ahmed, Nishat Ahmed, Saleha Ahmed, Fazil Ahmad, Abeer Mohammed Al-Subaie
Research Journal of Pharmacy and Technology | Volume - 13, Issue - 6, 2020

...Result: Results demonstrated that the level of estradiol, cholesterol and total serum protein level was ameliorated indicating anti-fibrotic effect of Emblica officinalis. Interpretation and Conclusion: Emblica officinalis contains uterine fibroid protective phytochemicals and may be useful in preventing uterine fibroids induced by MSG. This activity can be attributed to phenolic and other constituents and one of the mechanisms could be by balancing of oxidative stress, acting as anti-oxidant. (emblica officinalis is Chinese Goosberry) admin emphasis

Study on attenuation of neurotoxic effect of Mono Sodium Glutamate by Hydro alcoholic extract of roots of Glycyrrhiza glabra in rats - HERE (pdf available)

Upashana Banerjee, Binayaka Sethi, Bimalendu Chowdhury
Department of Pharmacology, Roland Institute of Pharmaceutical Sciences, Berhampur, Orissa, India
Conference Paper (PDF Available) · January 2013 | Conference: IPSCON 2012, Volume: ABSTRACT

... Background:
Monosodium glutamate (MSG) is a widely used additive used as a flavor enhancer for packaged food products. Glutamate in high doses produces neuroendocrine abnormalities, neurodegeneration and neurotoxicity due to oxidative stress.

Conclusion:
HAEGG established effective neuroprotective property by showing significant protection against oxidative stress. The data obtained reveals the ability of HAEGG to curb the toxic effects induced by consumption of MSG. ...

Comparison of the effects of perinatal and neonatal administration of sodium ferulate on repair following excitotoxic neuronal damages induced by maternal oral administration of monosodium glutamate at a late stage of pregnancy - HERE

Yongping Zhang(1), Lijian Yu(1), Rundi Ma(1), Xiaoyu Zhang(1,2), Tingxi Yu(1,3)
1 Key Laboratory of Mrine Materia Medica, Guangdong Ocean University, Zhanjiang, China
2 Department of Otorhinolaryngology—Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, USA
3 Shanghai Pediatric Medical Research Institute, Xinhua Hospital, Shanghai Jiao Tong University, Shanghai, China
World Journal of Neuroscience, 2012, 2, 159-165 WJNS

...Both maternal and newborn administration of SF is conducive to the filial neuronal repair following excitotoxic damages induced by glutamate.

Neuroprotective evaluation of standardized extract of 
Centella asciatica in monosodium glutamate treated rats HERE 
(pdf available - Cetella asciatica is commonly known as 'Pennywort')

M Ramanathan, S Sivakumar, P R Anandvijayakumar, C Saravanababu†, P Rathinavel Pandian†
Neuropharmacology Laboratory, Department of Pharmacology,
†Department of Phytochemistry & Phytomedicine, J. S. S. College of Pharmacy, Ootacamund, 643 001, India
Indian journal of experimental biology 45(5):425-31, June 2007

The effect of chloroform: methanolic (80:20) extract of C. asiatica (CA; 100 and 200 mg/kg), was evaluated on the course of free radical generation and excitotoxicity in monosodiumglutamate (MSG) treated female Sprague Dawley rats. The extract showed significant improvement in catalase, super oxide desmutase and lipid peroxides levels in hippocampus and striatum regions. Glutathione level was not altered with CA treatment. Similar observation was made with dextromethorphan. The general behavior, locomotor activity and CAl a region of the hippocampus was significantly protected by CA indicating neuroprotective effect of CA in MSG induced excitotoxic condition. Hence it can be concluded that CA protected MSG induced neurodegeneration attributed to its antioxidant and behavioural properties. This activity of CA can be explored in epilepsy, stroke and other degenerative conditions in which the role of glutamate is known to play vital role in the pathogenesis.

The Effect of Aqueous Extract of Ocimum gratissimum On 
Monosodium Glutamate Induced Biochemical Changes in Albino Rats - HERE

Dayo Adedoyin(1), Abiola  S. Ojokuku(1), Florence A. Bamidele(2)
1  Department. of Chemical Sciences, Yaba College of Technology, PMB 2011, Yaba, Lagos, Nigeria.
2 Department of Biological Science, Yaba College of Technology, PMB 2011, Yaba, Lagos, Nigeria.
Trop Journal of Natural Product Research | 2020; 4(2):27-30.  Published Date: 29 February 2020

...Occimum gratissimum aqueous extract affected some biochemical parameters induced by monosodium glutamate.

The Neuroprotective Effect of Dark Chocolate in Monosodium 
Glutamate-Induced Nontransgenic Alzheimer Disease Model Rats: Biochemical, 
Behavioral, and Histological Studies - HERE (pdf available)

Sowmya Madhavadas, Vijaya Kumar, Bindu Kutty, Sarada Subramanian
December 2015 Journal of Dietary Supplements 13(4):1-12

...The results demonstrated that DC reduced the hyperglycemia, inhibited the cholinesterase activity in the hippocampal tissue homogenates, and improved the cognitive performance in spatial memory related Barnes maze task. Histological studies revealed an increase in cell volume in the DC treated rats in the CA3 region of the hippocampus. These findings demonstrated the benefits of DC in enhancing cognitive function and cholinergic activity in the hippocampus of the aged NTAD rats while correcting their metabolic disturbances.

Effect of Monosodium Glutamate on Mice ovaries and 
the possible protective role of Vitamin C - HERE (2015 full report)

Snoor J. Mustaf (1), Tan Azad Salih (1), Hadeel A. Yasseen
(2), Bushra Hassan Marouf (3), Ali Ibrahim Mohammed (2)

Department of Anatomy, School of Medicine/University of Sulaimani, Iraq
Department of Histopathology, School of Medicine/University of Sulaimani, Iraq
Department of Pharmacology and Toxicology, School of Pharmacy/University of Sulaimani, Iraq

Background: Monosodium Glutamate, commonly used food additives that produce oxidative stress causing pathogenesis in several tissues and play a role in anovulatory infertility. ...

Conclusion:
MSG causes oxidative stress affecting ovarian tissue particularly the growingf ollicles, maturation of follicles, and decreased ovulation. Vitamin C is an effective antioxi-dant agent reducing the oxidative stress effect of MSG.

The possible protective effect of piperine versus vitamin C on monosodium glutamate-induced cerebellar toxicity in adult male rats a histological and immunohistochemical study - HERE

Omar, Abeer I.; Farag, Eman A.; Yousry, Marwa M.Author Information
Histology Department, Faculty of Medicine, Cairo, University, Cairo, Egypt
Egyptian Journal of Histology: December 2016 - Volume 39 - Issue 4 - p 362-371

...Both vitamin C and black pepper could preserve the cerebellum histologically in the MSG rat model. However, black pepper was more protective.

Combination of vitamin C and E modulated monosodium  glutamate-induced 
endometrial toxicily in female Wistar rats - HERE (pdf available)

Elly Dwi Wahyuni1, Cory Chorajon Situmorang1, Yuyun Yueniwati(2), Wisnu Barlianto(3), Pande Made Dwijayasa(4)

1 Midwifery Master Study Programme, Faculty of Medicine, Brawijaya University, Malang, East Java, Indonesia
2 Radiology Laboratory, Saiful Anwar General Hospital, Faculty of Medicine, Brawijaya University, Malang, East Java, Indonesia
3 Pediatric Laboratory, Saiful Anwar General Hospital, Faculty of Medicine, Brawijaya University, Malang, East Java, Indonesia
4 Obstetric and Ginaecology Laboratory, Saiful Anwar General Hospital, Faculty of Medicine, Brawijaya University, Malang, East Java, Indonesia
Asian Pacific Journal of Reproduction | June 2014

...Conclusions: The present data suggesting that combined vitamin C and E able to inhibit endometrial toxicity caused by orally MSG treatment via modulating angiogenesis, increase endometrial thickness and expression of -estrogen receptor.

Effect of monosodium glutamate on the fallopian tubes of adult albino rats and the possible protective role of vitamin C: A histological and immunohistochemical study - HERE

Rania A.Wahdan, Zeinab M. Alazouny
Egyptian Journal of Histology 38(1):68-76 · March 2015

...There was a significant increase in the area percentage of collagen fibers and a significant increase in the optical density of inducible nitric oxide synthase reaction in the treated group compared with the control group. In the vitamin C-supplemented group, there was improvement in the histological and immunohistochemical changes. Conclusion: Administration of MSG induces a degenerative effect on the fallopian tubes of adult rats, confirmed through the histological and immunohistochemical changes. However, vitamin C can improve these induced changes through its antioxidant effects.

Adverse Effects of Monosodium Glutamate on Liver and Kidney Functions in 
Adult Rats and Potential Protective Effect of Vitamins C and E - HERE (pdf)

Manal Said Tawfik(1)*, Nawal Al-Badr(2)
1 Department of Food Science and Technology, Faculty of Agriculture-El-Shatby, Alexandria University, Alexandria, Egypt;
2 Department of Food Nutrition, King Saud University, Riyadh, Saudi Arabia.
Food and Nutrition Sciences, 2012, 3, 651-659, Published Online May 2012

...The results showed that MSG at doses of 0.6 and 1.6 mg/g of body weight may cause an adverse effect on the hepatic and renal functions which might be due to oxidative stress induced by MSG on the liver and renal tissue. Supplementation of vitamin C and vitamin E was capable of ameliorating MSG-induced oxidative stress on hepatic and renal functions.

The effect of vitamin C administration on monosodium glutamate 
induced liver injury. An experimental study - HERE

Ayman EL-Meghawry, EL-Kenawy(a,c) Hosam Eldin Hussein, Osman(b,c) Maha Hasan, Daghestani(d)
a Molecular Biology Department, Genetic Engineering and Biotechnology Research Institute, Minufiya University, Egypt
b Department of Anatomy, Al Azhar University, Egypt
c College of Medicine, Taif University, Saudi Arabia
d Department of Zoology, King Saud University, Women Students-Medical Studies and Sciences Section, Saudi Arabia
Experimental and Toxicologic Pathology | Volume 65, Issue 5, July 2013, Pages 513-521

Severe alterations were recorded including dilatations of the central veins; severe cyto-architectural distortions of the hepatocytes; marked reduction in both carbohydrates and proteins; vacuolated cytoplasm, swollen mitochondria and vesiculated rough endoplasmic reticulum with picknotic nuclei; in addition to significant variation in the expression of ki-67 and p53 proteins. The data obtained from this study showed the improvements in the pathological architecture of the liver after treatment with vitamin C. The present data point to the ameliorative effect of vitamin C against MSG induced liver injury.

Protective Role of Co-administration of Vitamin D in 
Monosodium Glutamate Induced Obesity in Female Rats - HERE

Padmanabha Nandan(a), Arun Kumar NayanataraPh.D.(a) Roopesh Poojary M.Sc.(a), K.Bhagyalakshmi M.D.(a), M.NirupamaM.D.(b), Rekha D.Kini Ph.D.(a)
a Department of Physiology, Kasturba Medical College, Mangalore, Affiliated to Manipal University, Karnataka, India
b Department of Pathology, Kasturba Medical College, Mangalore, Affiliated to Manipal University, Karnataka, India
Journal of the National Medical Association | Volume 110, Issue 1, February 2018, Pages 98-102

...Conclusion
Ingestion of Vitamin D suppresses body weight gain in MSG-induced obese rats. Active agents in Vitamin D are useful for the prevention and treatment of obesity. Foods tested with high glutamate levels can be fortified with minute quantities of calcitriol to combat the adverse effects without compromising on the taste of the food processed. The fortification of junk foods might also combat largely prevalent Vitamin D deficiency in India.

Evidence of the protective effect of L-arginine and vitamin D against monosodium glutamate-induced liver and kidney dysfunction in rats - HERE full text  pdf available - HERE

Eman A.Elbassuoni(a1), Merhan M.Ragy(a1), Sabreen M.Ahmed(b1)
a Physiology Department, Minia University Faculty of Medicine, Minia University Faculty of Medicine, Minia, 61111, Egypt
b Human Anatomy Department, Minia University Faculty of Medicine, Minia University Faculty of Medicine, Minia, 61111, Egypt

...Results: MSG increased body weight and produced liver and kidney dysfunctions. The MSG-induced oxidative liver and kidney damage was proved. Vitamin D and l- Arginine have been shown to protect and restore the liver and the kidney capabilities in MSG models injury via inhibiting oxidative damage, vitamin D or l- Arginine suppresses the increased food intake and body weight gain induced by MSG. Conclusions: due to injurious effect of MSG, it should be avoided especially in liver or kidney disorders, foods containing excess MSG can be fortified with vitamin D or l- Arginine to overcome its adverse effects.

Effectivity of tomato (Solanum lycopersicum) and zinc combination to sperms of 
male white rats (Rattus norvegicus) exposed to monosodium glutamate - HERE (pdf)

I H Wirandoko(1), C Apriyani(1) and D R Apriyanto(1)

1. Faculty of Medicine, Swadaya Gunung Jati University, Jl. Terusan Pemuda, No.1A, Cirebon,
West Java, Indonesia 45132
Journal of Physics: Conference Series, Volume 1146

Abstract
Factors causing infertility include unhealthy lifestyle, such as excessive use of MSG which can produce free radicals and can affect morphology and motility of spermatozoa. Antioxidant is needed to prevent free radicals, which can be obtained from various sources such as tomatoes and zinc...Tomatoes or zinc and the combination of tomatoes and zinc were effective to improve the morphology and motility of male white rats Rattus norvegicus spermatozoa which were exposed to MSG. The combination of tomatoes and zinc were the most effective in improving morphology and motility of spermatozoa exposed to MSG.

Monosodium glutamate influences depressive behavior of two age groups of 
mice in forced swimming test: Vitamin B6 could remedy the situation - HERE

Azadeh Mesripour(a,b1), Masoud Kadivar(b), Valiollah Hajhashemi(b)
a Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
b Department of Pharmacology and Toxicology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
Personalized Medicine in Psychiatry | Volumes 15–16, July–August 2019, Pages 28-32

...In conclusion, MSG effects on depressive behavior depend on age and duration of exposure. Vitamin B6 as a cofactor of various neurotransmitter enzymes is promising in preventing the possible harmful effects of MSG on mood.

Evaluation of the alleviative role of Chlorella vulgaris and Spirulina platensis extract against ovarian dysfunctions induced by monosodium glutamate in mice - HERE (pdf available)

Sekena H Abdel-Aziem (a), Heba A.M. Abd El-Kader (a), Faten M. Ibrahim (b), Hafiza A Sharaf (c),
Aida I. El makawy (a)
a  Cell Biology Dept., 33 El Bohouth St., Dokki, Giza, Egypt
b  Medicinal and Aromatic Plants Research Dept., 33 El Bohouth St., Dokki, Giza, Egypt
c  Pathology Dept., National Research Centre, 33 El Bohouth St., Dokki, Giza, Egypt
Journal of Genetic Engineering and Biotechnology 16 (2018) 653-660

...Chlorella vulgaris and Spirulina platensis improved the monosodium glutamate ovarian tissue histological alteration, sex hormones content and raised the ovarian enzymatic antioxidants level. In addition, monosodium glutamate markedly diminished the Glutathione peroxidase, superoxide dismutase and catalase mRNA expressions, However, Chlorella vulgaris or Spirulina platensis upregulated the expression of genes close to control. In conclusion, Chlorella vulgaris and Spirulina platensis showed potential alleviative role against the monosodium glutamate ovarian dysfunction.

Neuroprotective Effect of Aqueous Extract of Garcinia kola on Monosodium Glutamate - Induced Cerebellar Cortical Damage in Adult Wistar Rats - HERE (pdf)

Ajibade Adeshina John(1), Fakunle Ponle Bamidele(1) and Shittu Oluwaseyi Ridwan(1)
1 Department of Anatomy, Ladoke Akintola University of Technology Ogbomoso, Oyo State, Nigeria.
European Journal of Medicinal Plants 5(1): 13-22, 2015

Conclusion: This study concluded that Garcinia kola has protective effects on monosodium glutamate-induced cerebellar damage in adult Wistar rats.

Curcumin Protects against Monosodium Glutamate Neurotoxicity and Decreasing 
NMDA2B and mGluR5 Expression in Rat Hippocampus - HERE (pdf available)

Rania M Khalil, Naglaa Khedr
Neurosignals 24(1):81-87 · August 2016

...The anti-inflammatory properties of CUR may be responsible for this observed neuroprotective action. A possible role of CUR to attenuate both glutamate level and gene expression of NMDA2B and mGLUR5 in brain hippocampus was established when compared to MSG group. Conclusion: We concluded that CUR as flavor enhancer protects against MSG-induced neurotoxicity in rats.

Fenugreek Seed Extract Prevents Fat Deposition in 
Monosodium Glutamate (MSG)-Obese Rats - HERE

P. Kumar - Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi, India
U. Bhandari  - Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi, India

...Results: Treatment with AqE-TFG produced significant (P < 0.05 or P < 0.01) reduction in body weight gain, Lee’s index, white adipose tissue (WAT) weights, adiposity index, blood glucose, serum insulin, leptin, lipids (low density lipoprotein cholesterol and very low density lipoprotein cholesterol), cardiac risk indexes (atherogenic index and coronary risk index), and homeostatic model assessment index. AqE-TFG treatment restored the activities of liver and epididymal WAT lipogenic enzymes (fatty acid synthetase and glucose-6-phosphate dehydrogenase) towards normal levels. Histological studies of liver also supported the experimental findings.

Conclusion: These findings demonstrated the preventive effect of AqE-TFG on fat deposition and dyslipidemia possibly by improvement in glucose and lipid metabolism, enhancement of insulin sensitivity and down regulation of lipogenic enzymes.

Effect of monosodium glutamate on the ovaries of adult female 
albino rats and the possible protective role of green tea - HERE

Ahmed Abozaid Ali, Ghada Hassan El-Seify, Hala Mohammed El Haroun, Mona Abd El Mawla Mohammed Soliman MSc
Department of Histology, Faculty of Medicine, Menofyia University, Menoufiya, Egypt
Year : 2014  |  Volume : 27  |  Issue : 4  |  Page : 793-800

...Conclusion
It has been concluded that GTE improves the histological changes caused by MSG in the ovary.

Neuroprotective Potential of Allium sativum against Monosodium Glutamate-Induced Excitotoxicity: Impact on Short-Term Memory, Gliosis, and
Oxidative Stress - HERE (pdf) available

Suzan M Hazzaa (1), Seham Ahmed Mohamed Abdelaziz (2), Mabrouk A Abd Eldaim (3), Mohamed M. Abdel-Daim (4,5), and Ghada E Elgarawany (1)
1 Department of Medical Physiology, Faculty of Medicine, Menoufia University, Shebeen Elkom 32511, Egypt
2 Department of Histology, Faculty of Medicine, Menoufia University, Shebeen Elkom 32511, Egypt
3 Department of Biochemistry and Chemistry of Nutrition, Faculty of Veterinary, Menoufia University,
Shebeen Elkom 32511, Egypt
4 Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
5 Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt
Nutrients | Published: 9 April 2020

...5. Conclusions
Monosodium glutamate severely affected the short-term spatial memory of rats through oxidative stress-induced degenerative changes and apoptosis of brain tissue. However, Allium sativum ameliorated MSG-induced degenerative and apoptotic changes in brain tissue through reducing the oxidative stress and gliosis-induced structural damage of the hippocampus and by increasing the protein expression of Ki-67 in brain tissue. This study suggested that Allium sativum is a potent neuroprotective agent against pollutant-induced nervous tissue damage.

Qing brick tea (QBT) aqueous extract protects monosodium glutamate-induced obese mice against metabolic syndrome and involves up-regulation Transcription Factor Nuclear Factor-Erythroid 2-Related Factor 2 (Nrf2) antioxidant pathway - HERE

Wenqi Ga(a), Changyi Xia(a), Jun Hu(a), Biaoxin Che(a), Chunyan Wang(c), Bangping Cui(d), Pengyi Deng(d), JianYang(a), Zhifang Deng(b)
a Department of Central Experimental Laboratory& Yichang Key Laboratory of ischemic cardiovascular and cerebrovascular disease translational medicine, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People’s Hospital, Yichang, 443003, China
b Department of Pharmacy, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People’s Hospital, Yichang, 443000, China
c Chang-sheng-chuan Hubei Qingzhuan Brick Tea Institute, Yichang, 443002, China
d Department of Nuclear Medicine, The First College of Clinical Medical Science, China Three Gorges University & Yichang Central People’s Hospital, Yichang, 443000, China
Biomedicine & Pharmacotherapy | Volume 103, July 2018, Pages 637-644

...Conclusion
Our results showed that QBT intake was effective in protecting monosodium glutamate-induced obese mice against metabolic syndrome and involved in the Nrf2 signaling pathway in the skeletal muscle.

Extract of Coelatura aegyptiaca, a freshwater clam, ameliorates 
hepatic oxidative stress induced by monosodium glutamate in rats - HERE

Amel M Soliman
African journal of pharmacy and pharmacology 5(3):398-408 · April 2011

...The results of the present study elucidate that CE could ameliorate the liver oxidative stress induced by MSG administration, since CE was strongly scavenged DPPH radicals and showed antioxidant activity.

Effect of Hibiscus sabdariffa on obesity in MSG mice - HERE

Francisco Alarcon, Alejandro Zamilpa, Ma Dolores Perez-Garcia, Julio César Almanza-Pérez
Article in Journal of Ethnopharmacology 114(1):66-71 · November 2007

...Our data confirm the anti-obesity effect of Hibiscus sabdariffa reported by the Mexican population.

CoQ10 ameliorates monosodium glutamate-induced alteration in detrusor activity and responsiveness in rats via anti-inflammatory, anti-oxidant and channel 
inhibiting mechanisms - HERE (full text) pdf available

Dalia F. El Agamy & Yahya M Naguib
BMC Urology | December 2019

...Olive oil had no effect on MSG induced alterations of different parameters. Treatment with CoQ10 has resulted in a significant restoration of all the altered parameters. Conclusion: Taken together, our results suggest that CoQ10 antagonizes the deleterious effects of MSG on detrusor activity. We propose that CoQ10 could be a therapeutic strategy targeting urinary bladder dysfunction.

Impact of coenzyme Q10 on the histological structure and immunohistochemical localization of leptin in the ampulla of rat oviduct after monosodium glutamate administration - HERE

Samar A. Asker
Article · June 2011

Background: The female reproductive system is very sensitive to different environmental chemicals and food additives such as monosodium glutamate. Coenzyme Q10 (CoQ10) is a naturally occurring compound and a potent antioxidant....

Conclusion: Administration of monosodium glutamate alters the histological structure and expression of leptin in the oviduct. The coadministration of CoQ10 with monosodium glutamate partially prevented these changes, suggesting a protective effect of CoQ10.

The effects of black garlic on the working memory and pyramidal cell number of 
medial prefrontal cortex of rats exposed to monosodium glutamate - HERE

Titis Nurmasitoh, Dwi Cahyani Ratna Sari & Ginus Partadiredja
Drug and Chemical Toxicology | Volume 41, 2018 - Issue 3, pages 324-329

...Black garlic may play a role as an antioxidant agent that prevents the prefrontal cortex from glutamate-induced oxidative stress. It is concluded that the ethanolic fermented garlic extract prevented the working memory impairment following MSG administration.

The effects of black garlic ethanol extract on the spatial memory and estimated total number of pyramidal cells of the hippocampus of monosodium glutamate-exposed adolescent male Wistar rats - HERE

Ery Hermawati, Dwi Cahyani Ratna Sari, Ginus Partadiredja
Anatomical Science International | September 2015, Volume 90, Issue 4, pp 275–286

Abstract
Monosodium glutamate (MSG) is believed to exert deleterious effects on various organs, including the hippocampus, likely via the oxidative stress pathway. Garlic (Alium sativum L.), which is considered to possess potent antioxidant activity, has been used as traditional remedy for various ailments since ancient times. ...
The spatial memory test was carried out using the Morris water maze (MWM) procedure, and the total number of pyramidal cells of the hippocampus was estimated using the physical disector design. The groups treated with black garlic extract were found to have a shorter path length than the C− and C+ groups in the escape acquisition phase of the MWM test...

STUDIES ON THE EFFECT OF MONOSODIUM GLUTAMATE (MSG) ADMINISTRATION ON THE ACTIVITY OF XANTHINE OXIDASE, SUPEROXIDE DISMUTASE AND CATALASE IN HEPATIC TISSUE OF ADULT MALE MICE - HERE (pdf)

Kuldip Singh and P. Ahluwalia
Department of Biochemistry, Pan jab University, Chandigarh
Indian Journal of Clinical Biochemistry, 2002, 17 (1) 29-33

ABSTRACT
Subcutaneous administration of monosodium glutamate (MSG), to normal adult male mice, for six consecutive days at dose levels of 4 and 8 mg/g body weight, significantly
increased the level of free radical initiating enzyme, xanthine oxidase, whereas the activity of free radical scavenging enzymes, like catalase and superoxide dismutase was significantly decreased in hepatic tissue. These observations suggested that ingestion of MSG at dose level of 4 mg/g body weight and above, induced oxidative stress in the hepatic tissue of adult male mice.

Ginger and Propolis Exert Neuroprotective Effects against 
Monosodium Glutamate-Induced Neurotoxicity in Rats - HERE

Usama K. Hussein,1,2 Nour El-Houda Y. Hassan,3 Manal E.A. Elhalwagy,4 Amr R. Zaki,5 Huda O. Abubakr,6 Kalyan C. Nagulapalli Venkata,7 Kyu Yun Jang,2, and Anupam Bishayee7,
Molecules | 2017 Nov; 22(11): 1928.

...The study clearly indicates a neuroprotective effect of ginger and propolis against MSG-induced neurodegenerative disorders and these beneficial effects could be attributed to the polyphenolic compounds present in these natural products.

Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats - HERE full text (and pdf here)

Jonas R. Sanches(1), Lucas M. França(1), Vinicyus T. Chagas(1), Renato S. Gaspar(1), Kayque A. dos Santos(1), Luciana M. Gonçalves(2), Deborah M. Sloboda(3), Alison C. Holloway(4), Richard P. Dutra(5), Everardo M. Carneiro(2), Ana Paula G. Cappelli(1) and Antonio Marcus de A. Paes(1)
1 Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão, São Luís, Brazil
2 Laboratory of Endocrine Pancreas and Metabolism, Department of Estructural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, Brazil
3 Departments of Biochemistry, Pediatrics and Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada
4 Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada
5Social, Health and Technological Sciences Center, Federal University of Maranhão, Imperatriz, Brazil
Front. Pharmacol., 10 March 2016 

...These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated with improvements in metabolic outcomes in MSG-induced obese rats.

Syzygium cumini Leaf Extract Reverts Hypertriglyceridemia 
via Downregulation of the Hepatic XBP-1s/PDI/MTP 
Axis in Monosodium L-Glutamate-Induced Obese Rats - HERE (pdf)

Lucas Martins França(1), Caio Fernando Ferreira Coêlho(1), Larissa Nara Costa Freitas(1), Ivana Letícia Santos Souza(1), Vinicyus Teles Chagas(1), Victor Debbas(2), Thais Martins de Lima(3), Heraldo Possolo de Souza(3), Francisco Rafael Martins Laurindo(2) and Antonio Marcus de Andrade Paes (1).
1 Laboratory of Experimental Physiology (LeFisio), Department of Physiological Sciences, Federal University of Maranhão, Av. dos Portugueses, 1966–Cidade Universitária Dom Delgado, São Luís, MA 65080-805, Brazil
2 Laboratory of Vascular Biology (LBV), Heart Institute, School of Medicine, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 44–Cerqueira César, São Paulo, SP 05403-900, Brazil
3 Laboratory of Medical Investigation (LIM-51), Emergency Medicine Department, School of Medicine, University of São Paulo, Av. Dr. Arnaldo, 455-Cerqueira César, São Paulo, SP 01246-903, Brazil
Oxid Med Cell Longev. 2019; 2019: 9417498.

Abstract
Syzygium cumini is used worldwide for the treatment of metabolic syndrome-associated outcomes... HESc restored fasting serum glucose, triglycerides, total cholesterol, and free fatty acids, as well as insulin sensitivity, to levels similar to lean rats. Additionally, HESc halved the triglyceride content into very low-density lipoprotein particles, as well as healed liver steatosis, in obese rats. Hepatic protein expression of the endoplasmic reticulum chaperone GRP94 was decreased by HESc, which also downregulated the hepatic triglyceride secretion pathway by reducing the splicing of X-box binding protein 1 (XBP-1s), as well as protein disulfide isomerase (PDI) and microsomal triglyceride transfer protein (MTP) translational levels. This action was further corroborated by the acute inhibitory effect of HESc on triglyceride accumulation on Triton WR1339-treated rats. Our data support the downregulation of the XBP-1s/PDI/MTP axis in the liver of MSG-obese rats as a novel feasible mechanism for the antihypertriglyceridemic effect promoted by the polyphenolic phytocomplex present in S. cumini leaf.

Study of the Protective Effects of Quince (Cydonia Oblonga) 
Leaf Extract on Fertility Alterations and Gonadal Dysfunction Induced by 
Monosodium Glutamate in Adult Male Wistar Rats HERE (pdf)

Davoud Kianifard (1), Gholamereza Vafaei Saiah (2), Farhad Rexaee(3)
1. Division of Histology & Microscopic Anatomy, Department of Basic Sciences
Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
2. Division of Physiology & Laboratory Animals Sciences, Department of Basic Sciences
Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
3. Department of Gastroenterology and Hepatology, Erasmus MC, University of Rotterdam, Rotterdam, the Netherlands
Rom J Diabetes Nutr Metab Dis. 22 (4): 375-384

...Conclusions:
The quince leaf extract can be effective in reduction of functional alterations of the reproductive system induced by monosodium glutamate.

HPLC analysis and role of the Saudi Arabian propolis in improving the 
pathological changes of kidney treated with monosodium glutamate - HERE (pdf)

Ahmed M. A. Abd El-Mawla(1,2), Husam Eldien H. Osman(3)
1 Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt.
2 Department of
Pharmacognosy, Faculty of Pharmacy, Taif University, Taif 21974, Saudi Arabia.
3 Department of Anatomy and Histology, Faculty of Medicine and Medical Sciences, Taif University, Taif 21974, Saudi Arabia

...CONCLUSION: The presence of phenolic compounds in the Saudi Arabian propolis is coincided with its role in improving the
histological and ultrastructural pictures of kidney treated with monosodium glutamate.

Effects of Dietary Vitamin B6 on the Utilization of Monosodium Glutamate by Rats - HERE

Chi-Pang Wen, Stanley N. Gershoff
The Journal of Nutrition, Volume 102, Issue 7, July 1972, Pages 835–840

... Vitamin B6 deficiency resulted in a delayed clearance from plasma of intravenously administered glutamate...These studies point up the need in MSG toxicity studies to especially consider the age and state of vitamin B6 nutriture of the animals used and the routes of MSG administration.

Vitamin E protects against monosodium glutamate-induced acute liver injury 
and hepatocyte ultrastructural alterations in rats - HERE

Refaat Eid, Mubarak Al-Shraim, Mohamed Sa. Zaki, Samaa Kamar, Noha S.Abdel Latif, Sally Negm, Bahjat Al-Ani & Mohamed Haidara
Ultrastructural Pathology 43(1):1-10 · October 2019

...Thus, vitamin E at 300 mg/kg effectively protects against MSG-induced acute liver injury in rats, possibly via the inhibition of inflammation, and up-regulation of endogenous antioxidants.

Alteration in some antioxidant enzymes in cardiac tissue upon 
monosodium glutamate [MSG] administration to adult male mice - HERE

Kuldip Singh (1), Ahluwalia Pushpa (2)
1. Department of Biochemistry, Govt. Medical College, Amritsar, India
2. Department of Biochemistry, Panjab University, Chandigarh, India
Indian Journal of Clinical Biochemistry | January 2005, Volume 20, Issue 1, pp 43–46

... A significant dose dependent increase in lipid peroxidation and xanthine oxidase level was observed, whereas the activity of free radical scavenging enzymes such as superoxide dismutase and catalase was decreased in both monosodium glutamate treated groups (Group-2 and Group-3). So, the present work suggested that monosodium glutamate at dose level of 4mg/g body weight and above induced oxidative stress in the cardiac tissue by changing the activity of free radical initiating enzyme such as xanthine oxidase and scavenging enzymes like superoxide dismutase and catalase.


Immune Functions and Role of Recovery (Biochemical 
and Histological study) HERE (pdf)

Zeinab A. Hassan(1,2), Manar Hamed Arafa(3), Wafaa Ibrahim Soliman(3), Hebatallah Husseini Atteia(4) and Hanan Fathy Al-Saeed(5)
1 Department of Histology and Cell Biology, Faculty of Medicine, Zagazig University, Egypt
2 Department of Anatomy, Faculty of medicine, Tibah university, Madina, Saudi Arabia
3 Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Zagazig University, Egypt
4 Department of Biochemistry, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
5 Department of Physiology, Faculty of Medicine for Girls, Al-Azhar University, Cairo, Egyp


...Taken together, the data showed that MSG consumption may have immunotoxic effects on the thymus and spleen of adult rats which is reversible but the normal structure of the spleen would need time to be regained. It is recommended that further studies aimed at corroborating these findings be carried out.

Effects of ascorbate on monosodium glutamate-associated 
toxicities that may impact upon immunocompetence - HERE

G.O. Obochi, S.P.Malu, V.S.Ekam, F.U.Uboh & M. Obi-Abang
Journal -Toxicological & Environmental Chemistry | Volume 91, 2009 - Issue 3 - Pages 547-557

...Data suggest that co-ingestion of ascorbate may help reduce the risk from some toxicities attributable to selective dietary constituents/additives.

Effects of monosodium glutamate administration in the neonatal 
period on the diabetic syndrome in KK mice. - HERE

Cameron DP, Poon TK, Smith GC.
Diabetologia. 1976 Dec;12(6):621-6.

Abstract
Administration of monosodium glutamate (MSG) to KK mice during the neonatal period resulted in a syndrome of obesity, stunting and hypogonadism. In some animals the genetic predisposition to diabetes was unmasked with the development of marked hyperglycaemia and or hyperinsulinaemia. Food intake was not increased compared to controls. The elevated plasma glucose and insulin in fed MSG treated mice fell rapidly with food deprivation. Glucose disposal was comparable in MSG treated and control mice after IP glucose, but after oral glucose MSG treated mice showed impaired glucose tolerance. Insulin secretion was defective in MSG treated mice after IP but not after oral glucose.
The modifying influence of aging on behavior in mice neonatally
 injected with monosodium glutamate - HERE

Max Goldman (1), George E. Stowe (1)
(1) Department of Biology University of South Dakota Vermillion USA
Psychopharmacology | June 1985, Volume 86, Issue 3, pp 359–364

Abstract
Newborn mice were injected with monosodium glutamate (MSG), and behavioral testing and physical development in neonatal, juvenile, adult, and aged mice were observed by means of a battery of appropriate tests. Early exposure to MSG resulted in altered behavioral performances postnatally, which were transitory and reflected the neurotoxicity of the chemical. Although behavioral deficits were not observed in mice neonatally treated with MSG at 1 month of age, a definite decline was manifested at 12 months and 34 months of age.

Neonatal Stress Alters Habituation of Exploratory Behavior 
in Adult Male but not Female Rats - HERE

M Dubovický* I Škultétyová†, D Ježová†
*Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovakia
†Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia

Pharmacolgy Biochemistry and Behaviour | Volume 64, Issue 4, December 1999, Pages 681-686

... Males proved to be more sensitive to neonatal stress associated with injections of MSG or hypertonic saline than females, and showed feminine-like habituation in the new environment. ...

Monosodium L-glutamate-induced obesity impaired the adrenal medullae activity - HERE

ACP Martins, HE Borges, RMG Garcia, SR Carniatto, PCF Mathias
Neuroscience Research Communications 28(1):49-58 · January 2001

Impairment of sympathoadrenomedullar system has been suggested to have a role in obesity. The activity of adrenal medullae (AM) isolated from 90-day-old obese-induced L-monosodium glutamate (MSG) male mice was studied. MSG treatment induced obesity without hyperphagia, while MSG-animals were shorter and lighter than the controls. Catecholamines (CA) gland content decreased in MSG-mice, while secretory response to carbachol was similar in isolated AM of both groups. However, high extracellular potassium did not stimulate CA secretion on AM isolated from obese animals as occurred in controls. Cholinesterase activity of adrenal glands homogenate was impaired in MSG-mice. Results suggest that MSG-hypothalamus lesions could cause impairment of sympathetic transmission in AM, which impose less CA accumulation and alter secretion response in AM. These defects might be involved at the onset of MSG obesity.

Effects of monosodium glutamate on the isolated retina of the 
chick embryo as a function of age: A morphological study - HERE (pdf available)

Janet C.Blanks(ab)
a Department of Ophthalmology, U.S.C. School of Medicine, Los Angeles, Ca. 90033, U.S.A.
b Estelle Doheny Eye Foundation, Los Angeles, Ca. 90033, U.S.A.

Liane Reif-Lehrer(cd)
c Department of Retina Research, Eye Research Institute of Retina Foundation Harvard Medical School, Boston, Ma. 02114, U.S.A.
d Department of Ophthalmology, Harvard Medical School, Boston, Ma. 02114, U.S.A.

Daniel Casper(ef)
e Department of Anatomy, Tufts University School of Medicine Boston, Ma. 02114, U.S.A.
f Department of Retina Research, Eye Institute of Retina Foundation, Boston, Ma. 02114, U.S.A.

Received 9 April 1980, Available online 7 September 2006.

... The adverse effects of monosodium glutamate (MSG) in embryonic chick retinas in culture were examined, as a function of embryonic age, by light and electron microscopy. From embryonic day 7 (E7) through E14, the presence of a low threshold concentration of glutamate in the incubating medium causes damage in the inner layers of the retina. Retinas from older embryos appear to be more susceptible to the destructive effects of MSG. As reported earlier for E12 retinas (Reif-Lehrer, Bergenthal and Hanninen, 1975), the lesion appears to be in the vitreal half of the inner nuclear layer with primarily amacrine and Müller cells being affected; with longer incubation periods ganglion cells also sustain damage. While damage from MSG has been documented in retina and other areas of the CNS in rodents treated with MSG in vivo, this is the first in-depth electron microscopic study of MSG damage to the isolated embryonic chick retina. ...

Monosodium glutamate induced convulsions in rats: Influence 
of route of administration, temperature and age - HERE

R. PeñafielA (1) CremadesF (2) Monserrat L.Puelles (3)

1. Departments of Biochemistry and Molecular Biology, Faculty of Medicine, University of Murcia, Murcia, Spain
2. Departments of Pharmacology, Faculty of Medicine, University of Murcia, Murcia, Spain
3. Departments of AnatomyFaculty of Medicine, University of Murcia, Murcia, Spain
Amino Acids | February 1991, Volume 1, Issue 1, pp 81–89

Summary
Treatment of developing rats with monosodium glutamate (MSG) produces an increase of glutamate levels in the brain, being this elevation dependent on both route of administration and animal's age. The capacity of exogenous MSG to induce convulsions seems to be related to the rate of glutamate elevation in the brain, rather than to the absolute value of glutamate concentration reached. Short exposure of MSG-treated rats to moderate hyperthermia potentiated the convulsive incidence and extended the brain damage to areas not affected by treatment with MSG alone, suggesting that the synergic effect of hyperthermia on glutamate neurotoxicity may be related to an increase in the permeability of the blood-brain barrier in the hyperthermic developing rats.

Effect of neonatal monosodium glutamate on the activities of glutamate dehydrogenase and aminotransferases in the circumventricular organs of rat brain. - HERE

Bawari M1, Nagesh Babu G, Ali MM, Misra UK.
1 Department of Neurology, SGPG Institute of Medical Sciences, P.O. Box 375, 226014, Lucknow, UP, India.
Amino Acids. 1995 Dec;8(4):393-5.

Abstract
Glutamate (Glu) the major amino acid in mammalian brain and most dietary proteins possesses neurotransmitter as well as neurotoxic properties. We administered monosodium glutamate (MSG) 4 mg/g bwt, sc on postnatal day (PND) 1 through 10 to rats on alternate days or daily and sacrificed them on PND 45 or PND 90 respectively. The activities of glutamate dehydrogenase and aminotransferases were evaluated in the circumventricular organs of brain. Results show that neonatal MSG produces alterations in glutamate metabolism in blood-brain-barrier deficient regions.

Monosodium L-Glutamate: Its Pharmacology and Role in the 
Chinese Restaurant Syndrome - HERE

Herbert H. Schaumburg, Robert Byck, Robert Gerstl, Jan H. Mashman.
Science  21 Feb 1969: | Vol. 163, Issue 3869, pp. 826-828

Abstract
Monosodium L-glutamate is the cause of the Chinese restaurant syndrome and can precipitate headaches. In appropriate doses it causes burning sensations, facial pressure, and chest pain. These are pharmacological effects obeying a dose-effect relationship. There is considerable variation in oral threshold does among individuals.

Monosodium glutamate induced lesions of the arcuate nucleus. 
I. Endocrine deficiency and ultrastructure of the median eminence. - HERE

Holzwarth-McBride MA, Hurst EM, Knigge KM.
Anat Rec. 1976 Oct;186(2):185-205.

Abstract
Monosodium glutamate was administered daily on days 5 through 10 postnatally at a dose of 2.5 mg/gm body weight. Counts of remaining perikarya in the arcuate nucleus of adult mice indicated approximately an 80% decrease in the number of perikarya. The arcuate lesion resulted in endocrine deficits; reporductive capacity was reduced, animals were smaller in stature and obese, and the weights of the anterior pituitary, ovaries and testes were significantly decreased while adrenals were unaffected. Light microscopic studies revealed no significant changes in thickness or general histological appearance of the median eminence. At the electron microscope level, there were no alterations in the number of nerve terminals or dense core vesicles per unit area in the contact zone. These observations suggest that afferents to the median eminence from the arcuate nucleus may form a relatively small portion of its total nerve terminal population.

Monosodium glutamate induced lesions of the arcurate nucleus. 
II. Fluorescence histochemistry of catecholamines. - HERE

Holzwarth-McBride MA, Sladek JR Jr, Knigge KM.
Anat Rec. 1976 Oct;186(2):197-205.

Abstract
The effect of the monosodium glutamate (MSG) induced lesion of the arcuate nucleus on catecholamines in the arcuate nucleus and median eminence of the mouse hypothalamus was determined using the Falck-Hillarp histofluorescence technique. The number of fluorescent perikarya in the arcuate nucleus of treated animals was decreased approximately 60%; the fluorescence intensity of surviving neurons was notably reduced. These changes were accompanied by a reduction in the intensity of fluorescence in the median eminence. Pretreatment of control and MSG-lesioned animals with a monoamine oxidase inhibitor (pargyline) greatly increased fluroescence in the median eminence and arcuate nucleus of both groups. However, the number of fluorescing perikarya of the arcuate nucleus of the normal pargyline treated group far exceeded that of the pargyline MSG animals. It is concluded that neonatally administered MSG caused destruction of a large number of dopaminergic arcuate perikarya.


Neurotoxic effects of neonatal injections of monosodium L‐glutamate (L‐MSG) 
on the retinal ganglion cell layer of the golden hamster: Anatomical and 
functional consequences on the circadian system - HERE

Dr. I. Chambille  J. Serviere
The Journal of Comparative Neurology | December 1993

Abstract
In rodents, daily injection of neurotoxic monosodium L‐glutamate (MSG) during the postnatal period induces retinal lesions, optic nerve degeneration with an alteration of visual pathway and an absence of the b‐wave in the electroretinogram. ...

Effects of monosodium glutamate on the development of intraventricular 
axons in the rat hypothalamus. - HERE
Mestres P, Rascher K.
Anat Embryol (Berl). 1983;168(3):433-44.

Abstract
The development of intraventricular axons in the infundibular recess of the young rat was investigated by correlative scanning and transmission electron microscopy (SEM-TEM). From the fourth through the fifteenth day of life such axons increase steadily in number. During subsequent weeks their number gradually decreases. In animals given monosodium glutamate on the fourth postnatal day there is widespread neuronal necrosis in the arcuate nucleus, and the development of intraventricular axons is greatly reduced. These findings suggest that the axons originate from the neurons of the arcuate nucleus.

Monosodium glutamate accelerates migration 
of hypothalamic perikarya at puberty - HERE

E. MaraniW. (1,2) J. Rietveld (1,2) M. E. Boon (1,2)
1.Laboratory Anatomy and Embryology, Department of Physiology, University of LeidenLeiden, The Netherlands
2.SSZD, Delft,The Netherlands
Histochemistry | June 1982, Volume 75, Issue 2, pp 145–150

Summary
The administration of monosodium glutamate (MSG) to newborn rats accelerates by two weeks the migration of fluorescent dopaminergic perikarya from the median eminence towards the arcuate nucleus at the time of puberty, which normally occurs from day 22 till 55 after birth. It is hypothesized that MSG affects the trigger mechanism for this migration. The disappearance of fluorescent dopaminergic cells that occurs after MSG administration is considered as a secondary effect.

Effect of age and monosodium-L-glutamate (MSG) treatment on neurotransmitter content in brain regions from male Fischer-344 rats - HERE (pdf available)

David Wallace - Oklahoma State University - Tulsa & R Dawson
Neurochemical Research 15(9):889-98 · October 1990 

...These data indicate that an acute, subconvulsive, dose of MSG may elicit neurochemical changes in both adult and aged male Fisher-344 rats, and that there are inherent age-related deficits in particular neurotransmitters in aged male Fisher-344 rats as indicated by the reductions in both monoamines and amino acids.

Lactate dehydrogenase and glutamate dehydrogenase activities in the circumventricular organs of rat brain following neonatal monosodium glutamate - HERE (pdf available)

M. Bawari, G. N. Babu*, M. M. Ali ~, U. K. Misra and S. V. Chandra 
~Department of Neurology, SGPG Institute of Medical Sciences, P.O. Box 375, Lucknow, 226 001 (India) and *Division of Neurotoxicology, Industrial Toxicology Research Centre, Lucknow (India)
Experientia 49(12):1092-4 · December 1993

... Evidence now exists for the neurotoxic actions of glutamate (glu), an excitatory transmitter and the most abundant amino acid in the mammalian brain (l, 2, 3) as well as in most dietary proteins (4). It has also been shown that several structural analogs of glu possess both neuroexcitatory and neurotoxic properties, and these have therefore been called excitotoxins .(5,6,7) Moreover, recent reports including our own indicate a generalized defect in glu metabolism in patients with motor neuron diseases a,9. Monosodium glutamate (MSG), the sodium salt of glu, has been shown to cause lesions in the developing brain of several animal species following its oral or systemic application in excessive amounts during the neonatal period (6, 7). 

Diabetic syndrome in the Chinese hamster induced with monosodium glutamate. - HERE

Komeda K, Yokote M, Oki Y.
Experientia. 1980 Feb 15;36(2):232-4.

Abstract
Neuronal necrosis in the arcuate and ventromedial hypothalamus regions is easily induced in 1-day-old Chinese hamsters by the administration of monosodium glutamate (MSG). New-born Chinese hamsters injected with MSG showed no sign of obesity, even when grown up, but apparently developed a diabetic syndrome.

Degree of damage compensation by various pacap 
treatments in monosodium glutamate-induced retinal degeneration - HERE

Norbert Babai (1), Tamás Atlasz (1), Andrea Tamás (2) Dóra Reglodi (2,3), Gábor Tóth (4), Péter Kiss (2) Róbert Gábriel(1,5)
1. Department of General Zoology and Neurobiology, Pécs University, Hungary
2. Department of Anatomy, Pécs, University Medical Faculty, Hungary
3. Neurohumoral Regulations Research Group of the Hungarian Academy of Sciences, Hungary
4. Department of Medical Chemistry, University of Szeged, Hungary
5. Adaptational Biology Research Group of the Hungarian Academy of Sciences, Hungary
Neurotoxicity Research | September 2005, Volume 8, Issue 3–4, pp 227–233

... Here we describe how different MSG treatments (1x and 3x application) cause retinal damage and finally lead to the destruction of the entire inner retina and how PACAP attenuates this effect...
... We conclude that (i) 2 or 3 times PACAP treatment attenuates retinal degeneration; (ii) one PACAP treatment does not provide protection against repeated excitotoxic insults, and (iii) repeated application of PACAP under these experimental conditions may lead to a primed state in which further neurotoxic insults are ineffective...

Effects of Monosodium Glutamate Wastewater on the Fish
 Ctenopharyngodon idellus and the Cabbage Brassica capestris - HERE

S. P. Cheng,(1) Y. B. Liu,(1) Y. B. Cui,(1) S. R. Ding,(1) Y. Z. Shi(2)
1 Department of Environmental Sciences and Engineering and the State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210093, People’s Republic of China
2 College of Basic Medicine, Nanjing University of Traditional Chinese Medicine and Pharmacology, Nanjing 210029, People’s Republic of China
Bull. Environ. Contam. Toxicol. (1996) 57:972-978
© 1996 Springer-Verlag New York Inc.

... Fifteen of these papers were from China, and the other was by Isik (1984) from the UK. So many publications indicate that the problems of MSG wastewater has not yet been solved and still has a great attraction for researchers... It was proven by this test that the untreated MSG wastewater had acute toxicity, which was demonstrated by the bioassay with the fish Ctenopharyngodon idellus (Sprague, 1970)...

Effect of monosodium glutamate on oxidative stress and apoptosis in rat thymus - HERE (pdf available)

Voja Pavlovic, Dusica Pavlovic, Gordana Kocic, Dusan Sokolovic, Tatjana Jevtovic-Stoimenov, Snezana Cekic, Dragana Velickovic
Mol Cell Biochem (2007) 303:161–166

Abstract 
It has been demonstrated that administration of high concentrations of monosodium glutamate (MSG), induce oxidative stress in different organs, but not in thymus... Obtained results showed that MSG treatment induced oxidative stress in thymus, which may have an important role in thymocyte apoptosis induced by MSG ...

Monosodium glutamate-induced oxidative kidney damage 
and possible mechanisms: a mini-review - HERE

Amod Sharma
Department of Physiology, Siriraj Hospital, Mahidol University, Bangkok, 10700 Thailand
Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002 Thailand
J Biomed Sci. 2015; 22: 93.

...Conclusions
During the last decade it became apparent that the chronic intake of MSG has potential effects on the peripheral organs such as the kidneys. Reduced antioxidant enzymes, increased lipid peroxidation, and tubulo-interstitial fibrosis brought on by high MSG intake strongly support the theory that oxidative stress is central to MSG-induced renal toxicity, with α-KGDH as a key player. Also, there is now evidence that excessive NMDA receptor activation is toxic for renal cells. However, a more clear association has to be established between α-KGDH, glutamate receptors, cystine-glutamate antiporter, and chronic MSG intake in order to provide a more comprehensive mechanism of renal oxidative stress. Approaches utilizing high throughput in vitro methods are crucial.

Toxic effects of wastewater from various phases of monosodium glutamate
 production on seed germination and root elongation of crops - HERE (pdf)

LIU Rui1,(3) ZHOU Qixing (2,4), ZHANG Lanying (1), GUO Hao(3)
1 College of Environment and Resources, Jilin University, Changchun 130026, China
2 Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
3 Liaoning Province Academy of Analytic Sciences, Shenyang 110015, China
4 College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
Front. Environ. Sci. Engin. China 2007, 1(1): 114–119

... 3 Results and discussion
3.1 Toxic effects of MSG wastewater on seed germination. 
The results showed that there were visible inhibitory effects of MSG wastewater on seed germination of wheat, Chinese cabbage, and tomato under the experimental conditions. ...

The Neonatal Treatment of Rats with Monosodium Glutamate Induces 
Morphological Changes in the Subfornical Organ - HERE

P Pesini,J L Rois, L Menéndez, S Vidal
Anatomia Histologia Embryologia 33(5):273-7 · November 2004

Abstract
The parenteral administration of monosodium glutamate (MSG) to neonatal rats induces specific lesions in the central nervous system that lead to a well characterized neuroendocrinological dysfunction. Additionally, it has been shown that MSG-treated rats present a blunted blood pressure response to the injection of nitric oxide synthase inhibitors. Recently, a similar cardiovascular alteration has been reported after the electrolytic lesion of the anteroventral region of the third ventricle affecting the connections of the subfornical organ (SFO). We hypothesized that the treatment of neonatal rats with MSG could affect the nitrergic cells of the SFO. In the present work, we have looked for alterations in the NADPH-diaphorase activity (a commonly used marker for nitrergic neurons) in the SFO of MSG-treated rats of either sex and at two different ages. Our results shown that the treatment of neonatal rats with MSG induced a substantial reduction in the volume of the SFO and in the number of its nitrergic cells with regard to control animals. These findings suggest that the SFO could be implicated in some of the cardiovascular alterations observed in MSG-treated rats.

Specific depletion of immunoreactive growth hormone-releasing 
factor by monosodium glutamate in rat median eminence - HERE

B. Bloch, N. Ling, R. Benoit, W. B. Wehrenberg & R. Guillemin
Nature volume 307, pages272–273 1984

Abstract
A potent and specific growth hormone-releasing factor (GRF) was recently isolated and characterized from a human islet cell tumour of the pancreas that caused acromegaly1–3. Antibodies raised against the synthetic replicate of this peptide have allowed the immunohistochemical identification of GRF-producing neurones within the primate central nervous system4. Such neurones are found mainly in the arcuate nucleus4–6 in human and monkey hypothalamus, suggesting that this nucleus is a primary source of GRF. We have further investigated this hypothesis by studying the anatomical organization of GRF neurones in rat hypothalamus, using an antibody raised against the recently characterized rat hypothalamic GRF7 in normal animals and in animals neonatally treated with monosodium glutamate (MSG), a treatment which results in the selective destruction of arcuate nucleus neurones8–10. We present here the results which show that GRF-producing neurones are located mainly in the arcuate nucleus of rats. MSG treatment results in the complete loss of GRF- immunoreactive cell bodies within this nucleus and provokes a selective disappearance of GRF-immunoreactive fibres in the median eminence. These results show that the arcuate nucleus is the origin of the GRF-containing fibres that project to the median eminence and establish the MSG-treated rat as an in vivo model for studying growth hormone secretion in the absence of neurohumoral GRF.

Neonatal monosodium glutamate administration alters 
noradrenergic measures in the brainstem of the mouse - HERE

Ralph DawsonJr.(1), ZoltanAnnau
1 Neurotoxicology Program, Department of Environmental Health Sciences The Johns Hopkins University, Baltimore, MD 21205 USA
Brain Research Bulletin Volume 15, Issue 2, August 1985, Pages 117-121

Abstract...The results suggest that MSG-induced damage to the arcuate nucleus produces selective alterations in brainstem NE systems. These alterations may reflect the toxic action of MSG on the opiomelanocortin neurons of the arcuate nucleus or other descending systems that are damaged by MSG. The loss of the descending opiomelanocortin input to the brainstem could result in these types of neurochemical consequences since the pharmacologie action of opiate drugs results in a selective enhancement of brainstem NE turnover in rodents.

Depression of delayed-type hypersensitivity in mice with hypothalamic lesion induced by monosodium glutamate: involvement of neuroendocrine system in immunomodulation - HERE

K. KATO, N. HAMADA, N. MIZUKOSHI, K.-I. YAMAMOTO, T. KIMURA, C. ISHIHARA, Y. FUJIOKA, T. KATO, K. FUJIEDAt & N. MATSUURAJ
Immunology 1986 58 389-395

... The results showed that DTH response was depressed in MSG-treated mice and that their plasma levels of adrenocorticotrophic (ACTH) were higher than those of their control mice. We also showed that the low DTH response in MSG-treated mice was due to dysfunction of DTH effector T cells and that DTH responses might be regulated by the neuroendocrine system in the hypothalamic-pituitary-adrenal axis. ...

Effect of Dietary Monosodium Glutamate on HFCS-Induced Hepatic Steatosis:
 Expression Profiles in the Liver and Visceral Fat - HERE (pdf)

Kate S. Collison, Zakia M. Maqbool, Angela L. Inglis, Nadine J. Makhoul, Soad M. Saleh, Razan H. Bakheet, Mohammed A. Al-Johi, Rana K. Al-Rabiah, Marya Z. Zaidi and Futwan A. Al-Mohanna1
Obesity (2010) 18, 1122–1134.(Obesity Society)

... MSG increased the expression of several genes implicated in adipocytes differentiation. We hypothesize that HFCS may promote hepatic steatosis, whereas dietary MSG induces dyslipidemia and markers of insulin resistance...
(Dyslipidemia is an abnormal amount of lipids in the blood).


Monosodium glutamate-induced lesions in the rat cingulate cortex - HERE

K. Rascher(1)
1.Lehrstuhl für Anatomie I, Ruhr-Universität Bochum, Bochum, Bundesrepublik Deutschland
Cell and Tissue Research | October 1981, Volume 220, Issue 2, pp 239–250

The brains of neonate albino rats were examined with the light and electron microscope following subcutaneous administration of monosodium glutamate (MSG). In addition to lesions in areas known to be vulnerable to glutamate, such as the arcuate nucleus of the hypothalamus, distinct areas of necrotic tissue were detected in the granular portion of the retrosplenial cingulate cortex. The affected cells display the cytological features characteristic of MSG-lesioned brain tissue, including vacuolization of the endoplasmic reticulum and clumping of chromatin. Numerous pyknotic nuclei can be detected as early as 3 h following treatment. The possible causes of the lesion, particularly the role that may be played by astrocytes, are discussed.

Effect of monosodium glutamate on the neural complex of Ciona intestinalis (Tunicata) - HERE

D. Georges(1)
1. Université Scientifique, Technologique et Médicale de Grenoble, Laboratoire de Biologie animale, France
Cell and Tissue Research | April 1988, Volume 252, Issue 1, pp 49–55

Short-term treatment of the ascidian (tunicate) Ciona intestinalis with monosodium glutamate produces a transient decrease in methionine-enkephalin-like immunoreactivity of neurones in the nervous ganglion. Moreover, it causes vacuolisation of the cells in the neural complex, particularly in the neural gland. Similar damages occur after ovariectomy. These results suggest that the ovary exerts an indirect influence on the neural gland via the nervous ganglion, and that the methionine-enkephalin-like substance could be the responsible “neuromediator”.

Regional effect of monosodium-L-glutamate on the superficial 
layers of superior colliculus in rat - HERE (pdf available)

László Seress, Gyula Lázár, Béla Kosaras, Richard Robertson
Cell and Tissue Research 235(2):453-457 · February 1984 

Systemic administration of monosodium-1-gluta-mate by single injections of 4 mg/g body weight in infant rats (2–10 days of age) results in acute swelling of cytoplasm and nuclear pyknosis of neurons in the stratum zonale and stratum griseum superficiale of the superior colliculus. Multiple daily doses of 4 mg/g body weight monosodium-1-glutamate result in an almost complete loss of neurons in these two superficial layers. The deeper layers appear not to be affected. No pathological effects were observed in the lateral geniculate body or pretectal complex. Light-and electron-microscopic studies reveal that the optic nerves are remarkably shrunken and many myelinated as well as unmyelinated axons are lost. Injection of 3Hproline into the vitreous body of one eye results in limited transport to the suprachiasmatic nucleus, lateral geniculate body and to lateral portions of the superior colliculus. The small percentage of intact axons in the optic nerve, as well as the limited proline transport from the eye, suggest that administration of monosodium-1-glutamate leaves intact some optic fibers, a portion of which belongs to the retinohypothalamic tract.

Brain lesions and short-term endocrine effects of monosodium L-glutamate 
in goldfish, Carassius auratus - HERE

Richard E. Peter, Olivier Kah, Christine R. Paulencu, Harry Cook, Ann L. Kyle
Cell and Tissue Research November 1980, Volume 212, Issue 3, pp 429–442

... At five and eight days post-injection only necrotic cells were found in the affected NLT region, but only a small band of necrotic cells was evident in the anterior-ventral preoptic region. No other brain lesions were evident. Serum levels of gonadotropin (GtH) were increased at 6 h, 24 h, and two days after treatment with MSG, but were similar to control values at five, seven and eight days after MSG in male and female goldfish. Exocytosis of small dark secretory granules in gonadotrophs was evident at 24 h after MSG in a fish with a somewhat greater increase in serum GtH than usually found. The time course of increased serum GtH levels postinjection of MSG is consistent with the observed time course of hypertrophy and atrophy of NLT neurons; the increase in serum levels of GtH is interpreted to reflect a stimulation of release of GtH-releasing factor from neurons in the NLT. Electron microscope investigation indicates that prolactin cells have increased secretory and synthetic activity from 24 h through to seven days post-injection of MSG. The mechanism for stimulation of the prolactin cells by MSG is not known...

Effects of monosodium l-glutamate on pituitary innervation 
in goldfish, Carassius auratus - HERE

Olivier Kah*, Richard E.Peter†, Pierrette Dubourg∗, HarryCook‡
∗Centre de Morphologie Expérimentale du CNRS, Avenue des Facultés, 33405 Talence, France
†Department of Zoology, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
‡The King's College, Edmonton, Alberta T5H 2M1, Canada
General and Comparative Endocrinology | Volume 51, Issue 3, September 1983, Pages 338-346

Abstract
Monosodium l-glutamate was injected intraperitoneally into goldfish at a dosage of 2.5 mg/g body wt. The first noticeable effect in the pituitary, 30 min postinjection, was a marked swelling of pituicytes in the neurohypophysis (NH). Eighteen hours postinjection a large number of degenerating type B fibers were found in the NH of the proximal pars distalis (PPD), while all type A fibers, and type B fibers in other parts of the pituitary, remained unaffected. Because glutamate causes a lesion in the nucleus lateral tuberis (NLT), from the anterior margin of the pituitary stalk through to the posterior end of the nucleus, and a minor lesion in the nucleus preopticus periventricularis, it is likely that the NLT is the origin of the degenerative type B fibers in the proximal NH. The significance of these results is discussed in relation to the neuroendocrine regulation of the pituitary functions in goldfish.

Nutrigenomics of hepatic steatosis in a feline model: effect of 
monosodium glutamate, fructose, and Trans-fat feeding. HERE

Collison KS(1), Zaidi MZ, Saleh SM, Makhoul NJ, Inglis A, Burrows J, Araujo JA, Al-Mohanna FA.
1 Cell Biology and Diabetes Research Unit, Department of Biological and Medical Research, MBC 03, King Faisal Specialist Hospital and Research Centre, P. O. Box 3354, Riyadh, 11211, Saudi Arabia
Genes Nutr. 2012 Apr;7(2):265-80

... Our feline model examining gene-diet interactions (nutrigenomics) demonstrates how dietary MSG, Trans-fat, and HFCS may contribute to the development of hepatic steatosis.
(hepatic steatosis - fatty liver)

The response of the hypothalamus to high doses of monosodium glutamate in mice and monkeys: Cytochemistry and ultrastructural study of lysosomal changes - HERE

R. Abraham, W. Dougherty, L. Golberg, F. Coulston
Institute of Experimental Pathology and Toxicology, Albany Medical College, Albany, New York 12208 USA
Experimental and Molecular Pathology Volume 15, Issue 1, August 1971, Pages 43-60

... Cytochemical and ultrastructural studies on the hypothalamus of the affected mice demonstrated a significant increase in the number of lysosomes, with appearance of numerous myeloid bodies. The presumptive intermediate stage of autophagic vacuole formation was not seen. The lysosomal effects observed have served to delineate hitherto unsuspected changes in the cell cytoplasm in affected animals. ...

The postweaning housing environment determines expression of learning deficit 
associated with neonatal monosodium glutamate (M.S.G.) HERE

Kim N.Fisher, Ruth A.Turner, Gaby Pineault, Jeff Kleim Matti, J.Saari
Neuroscience Research Unit, Nipissing University College, 100 College Drive, North Bay, Ontario, Canada, P1B 8L7
Neurotoxicology and Teratology | Volume 13, Issue 5, September–October 1991, Pages 507-513

Abstract
Perinatal M.S.G. treatment causes a syndrome characterized by damage to the hypothalamic arcuate nucleus, other circumventricular areas, parts of the visual system and the dentate gyrus of the hippocampus. The resulting hormonal dysfunction may be responsible for developmental anomalies of organ systems, obesity, and alterations in sensory/motor performance. We have shown that some behavioral indicators of M.S.G. toxicity in rats can be masked by rearing them in enriched housing conditions. Here, we evaluated the impact of six housing conditions on M.S.G.-induced alterations of organ systems and behavior. Perinatal M.S.G. treatment reduced adrenal, heart and testes weights, as well as total white blood cell (WBC) counts, and increased tail flick latencies. These measures were unaffected by the housing condition. M.S.G.-induced reductions in body weight, grip strength, water maze and dominance task performance varied as a function of housing. Deficits in water maze performance were most evident following social and isolated single-cage housing. We propose that deficits in water maze performance following perinatal M.S.G. may be attributable to hippocampal damage that can be alleviated by rearing the rats in stimulating environments.

Monosodium glutamate neonatal treatment as a 
seizure and excitotoxic model - HERE (pdf available)

Silvia J López-Pérez, Monica Elisa Ureña-Guerrero & Alberto Morales-Villagrán - University of Guadalajara
Brain research 1317:246-56 · March 2010

Monosodium glutamate (MSG) subcutaneously administrated to neonatal rats induces several neurochemical alterations in the brain, which have been associated with an excitotoxic process triggered by an over activation of glutamate receptors; however there are few systematic studies about initial changes in intracerebroventricular (i.c.v.) Glu levels produced by MSG in the brain. Thus, to characterize these changes, rat pups were injected with a MSG solution at 1, 3, 5 and 7 postnatal days (PD), and i.c.v. Glu levels and hippocampal total content of related amino acids (Asp, Glu, Gln, Gly, Tau, Ala and GABA) were estimated before, immediately and after each injection. Behavioral and EEG responses were also monitored after MSG administrations. Significant rise in i.c.v. Glu levels were found, mainly in response to the first and second injection. Moreover, the total content of all amino acids evaluated also increased during the first hour after the first MSG administration but only Glu and GABA remained elevated after 24 h. These biochemical modifications were accompanied with behavioral alterations characterized by: screeching, tail stiffness, head nodding, emprosthotonic flexion episodes and generalized tonic-clonic convulsions, which were associated with electroencephalographic pattern alterations. Altered behavior found in animals treated with MSG suggests an initial seizure situation. Although four MSG administrations were used, the most relevant findings were observed after the first and second administrations at PD1 and PD3, suggesting that only two MSG injections could be sufficient to resemble a seizure and/or excitotoxic model.

Monosodium glutamate in standard and high-fiber diets: 
metabolic syndrome and oxidative stress in rats - HERE

Yeda Sant’Diniz M.D.(ab), Luciane A.Faine M.D.(ab), Cristiano M.Galhardi M.D.(ab), Hosana G.Rodrigues M.D.(ab), Geovana X.Ebaid M.D.(b), Regina C.Burneiko M.D.(ab), Antonio C.Cicogna Ph.D.(ab), Ethel L.B.Novelli Ph.D.(b)

a Department of Clinical Cardiology, Faculty of Medicine, University of São Paulo State, Botucatu, São Paulo, Brazil
b Department of Chemistry and Biochemistry, Institute of Biological Sciences, University of São Paulo State, Botucatu, São Paulo, Brazil
Nutrition | Volume 21, Issue 6, June 2005, Pages 749-755

... Conclusions
MSG added to a standard diet increased food intake. Overfeeding induced metabolic disorders associated with oxidative stress in the absence of obesity. The fiber-enriched diet prevented changes in glucose, insulin, leptin, and triacylglycerol levels that were seen in the MSG group. Because the deleterious effects of MSG, i.e., induced overfeeding, were not seen in the animals fed the fiber-enriched diets, it can be concluded that fiber supplementation is beneficial by discouraging overfeeding and improving oxidative stress that is induced by an MSG diet.

Effects of maternal oral administration of monosodium glutamate at a 
late stage of pregnancy on developing mouse fetal brain. HERE

Yu T1, Zhao Y, Shi W, Ma R, Yu L.
1 Department of Neurophysiology, Xian Medical University, People's Republic of China.
Brain Res. 1997 Feb 7;747(2):195-206.

Abstract
Monosodium glutamate (MSG) was shown to penetrate placental barrier and to distribute to embryonic tissues using [3H]glutamic acid ([3H]Glu) as a tracer. However, the distribution is not even; the uptake of MSG in the fetal brain was twice as great as that in the maternal brain in Kunming mice. Other maternal mice were given per os MSG (2.5 mg/g or 4.0 mg/g body weight) at 17-21 days of pregnancy, and their offspring behaviors studied. The results showed that maternal oral administration of MSG at a late stage of pregnancy decreased the threshold of convulsion in the litters at 10 days of age. Y-maze discrimination learning was significantly impaired in the 60-day-old filial mice. On the other hand, no significant difference in spatial learning or tail flick latency was measured between the experimental animals and the controls. The filial mice of MSG-treated mothers could either not grasp a rope tightly, or grasped the rope tightly but could not crawl along the rope at the beginning of the training. However, such mice, after training, could grasp and crawl along the rope as well as controls. Obvious neuronal damage was not detected in the periventricular organs or the hypothalamus under a light microscope. The rate of weight gain for experimental animals was greater than for controls throughout the period from 20 to 90 days. Mating of treated males with treated females resulted in pregnancies and normal offspring, indicating that oral administration of MSG at a late stage of pregnancy did not affected the reproductive capacity of the offspring. The possible differences and relationship between MSG-induced damage to developing human and rodent brain are discussed.

The efficacy of probiotics for monosodium glutamate-induced obesity: 
dietology concerns and opportunities for prevention - HERE (full report)

Oleksandr A Savcheniuk(1), Oleksandr V Virchenko(1), Tetyana M Falalyeyeva(1), Tetyana V Beregova(1), Lidia P Babenko(2), Liudmyla M Lazarenko(2), Olga M Demchenko(3), Rostyslav V Bubnov(2,4) and Mykola Ya Spivak(2,3)
EPMA J. 2014; 5(1)

...Conclusions
The introduction of MSG to newborn rats caused the obesity in adulthood. Periodic administration of probiotic mixture to rat injected with MSG neonatally resulted in recovery of lipid metabolism and prevention of the obesity development.

Neonatal monosodium glutamate alters circadian organization of 
feeding, food anticipatory activity and photic masking in the rat - HERE

R.E.Mistlberger, M.C.Antle
Department of Psychology, Simon Fraser University, 888 University Drive, Burnaby, BC, Canada, V5A 1S6
Brain Research | Volume 842, Issue 1, 18 September 1999, Pages 73-83

Abstract
In rodents, parenteral administration of monosodium glutamate (MSG) induces marked degeneration of the retina and arcuate nucleus (AN) and disrupts daily rhythms of food intake. We quantified the effects of neonatal MSG (2 mg/g SC, postnatal days 1, 3, 5, 7, 9) on the expression of feeding and activity rhythms in adult rats under schedules of light–dark (LD), constant dark (DD), restricted daily feeding and total food deprivation. AN lesions were confirmed by neuropeptide Y (NPY) immunocytochemistry and Nissl stain. Compared to age-matched control rats, the amplitude (quantified as LD ratios) of daily food intake and food-bin activity rhythms was significantly attenuated in MSG rats in LD 12:12 and on the first day of DD. Control rats, but not MSG rats, showed lower amplitude rhythms in DD compared to LD. The phase angle of feeding and activity rhythms did not differ between groups in either condition. In a short LD cycle (2:2), control rats, but not MSG rats, showed significant inhibition (masking) of activity during the 2 h light periods. When food access was restricted to a 4 h daily meal, MSG rats showed enhanced expression and persistence of food-entrained anticipatory activity rhythms by comparison with control rats. These results indicate that attenuation of daily feeding rhythms in MSG rats is due in part to loss of direct inhibitory effects of light on behavior, and that the AN likely modulates, but does not mediate entrainment of feeding-related rhythms to daily cycles of LD or food access.

Neonatal monosodium glutamate treatment alters rat intestinal 
muscle reactivity to some agonists - HERE

Sergey N.Sukhanov(a), Iracema S.de Andrade(b) Miriam S.Dolnikoff(b) Alice T.Ferreira(a)
a Department of Biophysics, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Sao Paulo, SP CEP 04023-062, Brazil
b Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Sao Paulo, SP CEP 04023-062, Brazil
European Journal of Pharmacology | Volume 386, Issues 2–3, 15 December 1999, Pages 247-252

Abstract
The following study is an investigation of the changes in the contractile reactivity of visceral muscles in response to agonists and alterations in metabolic parameters after neonatal rat treatment with monosodium-l-glutamate. This treatment markedly sensitizes ileum and colon preparations to adenosine-5′-triphosphate (ATP) stimulation and also increases the colon activity to acetylcholine (p<0.05). Response to bradykinin remained unchanged, while ileum activity to angiotensin II was characterized by a reduction in the maximal tension (Emax) and an increase in the EC50 (p<0.05) value. The responses of nonintestinal muscle preparations from monosodium-glutamate-treated rats to both ATP and bradykinin did not show a significant difference when compared to the controls. This treatment diminished food intake, feces excretion and increased plasma insulin, nonesterified fatty acids and triglyceride concentrations (p<0.001). These results suggest that the changes in intestinal muscle activity, in response to agonists, can be due to metabolic alterations as well as the monosodium glutamate action on enteric neurons and/or smooth muscle receptors.

Deficits in Water Escape Performance and Alterations in Hippocampal Cholinergic Mechanisms Associated With Neonatal Monosodium Glutamate Treatment in Mice - HERE

P.T.-H Wong(a), H Neob W.L Teo(a),H Feng(a),Y.D Xue(a),W.H Loke(b)
a Department of Pharmacology, Faculty of Medicine, National University of Singapore, Kent Ridge, Singapore 119260 USA
b Department of Psychology and Social Work, Faculty of Arts and Social Science, National University of Singapore, Kent Ridge, Singapore 119260 USA
Pharmacology Biochemistry and Behavior | Volume 57, Issues 1–2, May–June 1997, Pages 383-388

Abstract
Mice treated neonatally with monosodium glutamate (MSG) were found to have learning and memory deficits in performing a non-spatial water escape task...

Reduction of 125I-angiotensin II binding sites in rat brain 
following monosodium glutamate treatment HERE

Ivo Rogulja**Joseph W.Harding**Sue Ritter**
Department of Veterinary and Comparative Anatomy, Pharmacology, Physiology, Washington State University, Pullman, WA, U.S.A.
Brain Research | Volume 419, Issues 1–2, 1 September 1987, Pages 333-335

...The results suggest that MSG can destroy angiotensin-sensitive neurons in circumventricular structures, which are located primarily outside the blood-brain barrier...

Effects of neonatally administered monosodium glutamate on the sexually dimorphic profiles of circulating growth hormone regulating murine hepatic monooxygenases - HERE

Nisar A.Pampori, Bernard H.Shapiro
Laboratories of Biochemistry, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104-6048, U.S.A.
Biochemical Pharmacology | Volume 47, Issue 7, 29 March 1994, Pages 1221-1229

...Generally, both doses of MSG produced the same developmental defects. Mice neonatally exposed to the amino acid developed a syndrome characterized by retarded growth, obesity and reduced organ weights...

Changes of Exploratory Behaviour and Its Habituation in Rats 
Neonatally Treated with Monosodium Glutamate - HERE

M Dubovicky(a), D Tokarev(b), I Skultetyova(b), DJezova(b)
a Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovakia
b Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia
Pharmacology Biochemistry and Behavior | Volume 56, Issue 4, April 1997, Pages 565-569

Abstract
...These results suggest a negative effect of neonatal stress and treatment with MSG on habituation to a new environment in male rats...

Neonatal monosodium glutamate treatment abolishes both delta opioid receptor-induced and alpha-2 adrenoceptor-mediated gastroprotection in the lower brainstem in rats - HERE

András Z Róna(a),Klara Gyire(a), István Barna(b), Katalin Müllner(a) Miklós Palkovits(c)
a Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary
b Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony u 43, H-1083 Budapest, Hungary
c Department of Anatomy, Semmelweis University, Tűzoltó u 59, H-1094 Budapest, Hungary
Journal of Physiology-Paris | Volume 95, Issues 1–6, January–December 2001, Pages 215-220

Abstract
Neonatal monosodium glutamate treatment reduced immunoreactive beta-endorphin content in the mediobasal hypothalamus by 50% in adult, male Wistar rats as compared to hypertonic saline-treated littermates; there was also a moderate (approx. 25%) reduction in the rostral part of the nucleus of the solitary tract...

Fasting-induced increases in food hoarding are elevated in 
adult hamsters treated neonatally with monosodium glutamate (MSG). HERE

M. Dailey, C.Vaughn, T.J. Bartness
Department of Biology, Center for Behavioral Neuroscience Georgia State University, Atlanta, GA 30302, USA
Appetite | Volume 49, Issue 1, July 2007, Page 285

... Surprisingly, food hoarding in MSG-treated animals was increased 100% more than controls with refeeding after a 56 h fast, with the greatest increase occurring during the first hour postfast. The underlying cause of this increase could be MSG-induced increased NPY receptors shown to occur in MSG-treated rats that also have an exaggerated NPY-induced increased food intake. These data suggest a similar increase in NPY receptors with MSG treatment in Siberian hamsters...

Monosodium glutamate-induced damage in liver and kidney: 
A morphological and biochemical approach - HERE (pdf available)

Genaro Gabriel Ortiz, Oscar Kurt Bitzer Quintero, Carlos Beas Zarate, S Rodríguez-Reynoso
Biomedicine & Pharmacotherapy 60(2):86-91 · March 2006

Abstract
It has been demonstrated that high concentrations of monosodium glutamate in the central nervous system induce neuronal necrosis and damage in retina and circumventricular organs. In this model, the monosodium glutamate is used to induce an epileptic state; one that requires highly concentrated doses. The purpose of this study was to evaluate the toxic effects of the monosodium glutamate in liver and kidney after an intra-peritoneal injection. For the experiment, we used 192 Wistar rats to carry out the following assessments: a) the quantification of the enzymes alanine aminotransferase and aspartate aminotransferase, b) the quantification of the lipid peroxidation products and c) the morphological evaluation of the liver and kidney. During the experiment, all of these assessments were carried out at 0, 15, 30 and 45 min after the intra-peritoneal injection. In the rats that received monosodium glutamate, we observed increments in the concentration of alanine aminotransferase and aspartate aminotransferase at 30 and 45 min. Also, an increment of the lipid peroxidation products, in kidney, was exhibited at 15, 30 and 45 min while in liver it was observed at 30 and 45 min. Degenerative changes were observed (edema-degeneration-necrosis) at 15, 30 and 45 min.

Excitotoxic neonatal damage induced by monosodium glutamate reduces several GABAergic markers in the cerebral cortex and hippocampus in adulthood - HERE (pdf available)

Monica Elisa Ureña-Guerrero, Sandra Orozco-Suárez, Silvia J López-Pérez, Mario Eduardo Flores Soto
International journal of developmental neuroscience: the official journal of the International Society for Developmental Neuroscience 27(8):845-855 · December 2009

Abstract
Monosodium glutamate (MSG) administered to neonatal rats during the first week of life induces a neurodegenerative process, which is represented by several neurochemical alterations of surviving neurons in the brain, where signalling mediated by GABA is essential for excitation threshold maintenance. GABA-positive cells, [3H]-GABA uptake, expression of mRNA for GABA transporters GAT-1 and GAT-3, and expression of mRNA and protein for two main GABA synthesizing enzymes, GAD65 and GAD67, were measured at postnatal day 60, after MSG neonatal treatment in two critical cerebral regions, cerebral cortex and hippocampus. GABA-positive cells, [3H]-GABA uptake, and mRNA for GAT-1, were significantly diminished in both cerebral regions. In the cerebral cortex, MSG neonatal treatment also decreased the mRNA for GAD67 and protein for GAD65 without significant changes in its corresponding protein and mRNA, respectively. Moreover in the hippocampus, mRNA and protein for GAD65 were increased, whilst GAD67 protein was elevated without significant changes in its mRNA. Clearly these results confirm the GABA cells loss after MSG neonatal treatment in both cerebral regions. As most of the GABAergic markers measured were reduced in the cerebral cortex, this region seems to be more sensitive than hippocampus, where interesting compensatory changes over GAD65 and GAD67 proteins were observed. However, it is possible that others neurotransmission systems are also compensating the GABA-positive cells loss in the cerebral cortex, and that elevations in two main forms of GAD in the hippocampus are not sufficient to maintain the neural excitation threshold for this region.

Cox-2 inhibition attenuates cardiovascular and inflammatory 
aspects in monosodium glutamate-induced obese rats - HERE

N.V.Cunha(a), S.B.de Abreu(a), C.Panis(b), S.Grassiolli(a), F.A.Guarnier(b), R.Cecchini(b) T.L.Mazzuco(b), P.Pinge-Filho(b), M.C.Martins-Pinge(a)
a Department of Physiological Sciences, State University of Londrina, Londrina, Paraná, Brazil
b Department of Pathological Sciences, State University of Londrina, Londrina, Paraná, Brazil
Life Sciences | Volume 87, Issues 11–12, 11 September 2010, Pages 375-381

...Significance
Our data demonstrate an association between increased blood pressure and products of COX-2 in obese rats, suggesting a role for prostaglandins in the hypertensive and inflammatory aspects of MSG-induced obesity...

Central but not peripheral glucoprivation is impaired 
in monosodium glutamate-treated rats. HERE

de Andrade IS(1), Gonzalez JC, Hirata AE, Carneiro G, Amado D, Cavalheiro EA, Dolnikoff MS.
1 Department of Physiology, Division of Neurophysiology and Endocrine Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, SP 04023-060, Brazil.
Neurosci Lett. 2006 May 1;398(1-2):6-11.

... It seems likely that the excitatory neural pathway that controls lipid metabolism and is present in C rats was destroyed by the MSG treatment...

(Developmental neuroscience)
Temporal and spatial expression of preprotachykinin A mRNA in the developing filial mice brain after maternal administration of monosodium glutamate at a late stage of pregnancy - HERE

L.Xu(a), Y.Zhao(a), S.-Q.Zhan(a), X.-D.Tang(b), Y.Guo(a), H.-S.Wang(a), C.Yang(c)
a Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi’an Jiaotong University, Department of Physiology and Pathophysiology, Xi’an Jiaotong University School of Medicine, Xi’an, Shaanxi 710061, China
b Department of Pathology and Anatomy, Eastern Virginia Medical School, Norfolk, VA 23507, USA
c Departments of Neuroscience, Anatomy and Cell Biology, University of Florida, Gainesville, FL 32601, USA
Neuroscience | Volume 145, Issue 3, 30 March 2007, Pages 974-980

...These results show that maternal administration of excessive MSG at a late stage of pregnancy significantly decreases PPT A mRNA expression in most of the brain regions of filial mice. This suggests that glutamate-induced excitotoxicity may affect the metabolism of precursors of substance P in developing brain neurons. The present study provides insights into the plasticity and vulnerability of neuron in different brain regions to glutamate excitotoxicity.

Dietary trans-fat combined with monosodium glutamate 
induces dyslipidemia and impairs spatial memory - HERE

Kate Collison, Nadine J Makhoul, Angela Inglis. Mohammad A Aljohi
Physiology & Behavior 99(3):334-342 · March 2010 

...Conclusion: Dietary trans-fat combined with MSG increased central adiposity, promoted dyslipidemia and impaired spatial learning.

The neuroprotective effects of PACAP in monosodium glutamate-induced 
retinal lesion involve inhibition of proapoptotic signaling pathways - HERE

Boglárka Rácz(a), Ferenc  GallyasJr.(b), Péter Kiss(c) Gábor Tót(d), Orsolya Hegyi(d), Bálazs Gas(a),Bálazs Borsiczky(a) Andrea Ferenc(a), Erzsebét Rőth(a), Andrea Tamás(c)
István Lengvári(c), Andrea Lubics(c), Dóra Reglődi(c)
a Department of Surgical Research and Techniques, University of Pecs, Hungary
b Department of Biochemistry and Medical Chemistry, University of Pecs, Hungary
c Department of Anatomy (Neurohum. Regul. Res. Group of the Hungarian Academy of Sciences), University of Pecs 7624 Pécs, Szigeti u 12, Hungary
d Department of Medical Chemistry, University of Szeged, Hungary
Regulatory Peptides | Volume 137, Issues 1–2, 15 November 2006, Pages 20-26

...In summary, our results show that PACAP treatment attenuated the MSG-induced changes in apoptotic signaling molecules in vivo and suggest that also endogenously present PACAP has neuroprotective effects. These results may have further clinical implications in reducing glutamate-induced excitotoxicity in several ophthalmic diseases...

Monosodium glutamate lesions inhibit the N-methyl-D-aspartate-induced 
growth hormone but not prolactin release in rats - HERE
Dóra Zelena(a), Daniela Jezova(a)∗, Zsuzsanna Ács(a), Gábor B.Makara(a)
aInstitute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, P.O.B. 67, H-1450 Hungary
∗Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Vlarska 3, 833 06 Slovak Republic
Life Sciences | Volume 62, Issue 22, 24 April 1998, Pages 2065-2072

Abstract
Large doses of glutamate administered to newborn rats damage permanently the neurones in the hypothalamic arcuate nucleus containing the growth hormone releasing hormone and the prolactin inhibiting dopamine neuron cell bodies. Since adult animals that underwent neonatal glutamate treatment still have a relatively well functioning growth hormone and prolactin system, we tested whether in the adults the excitatory amino acid sensibility is changed.

Behavioral deficits in monosodium glutamate rats: Specific 
changes in the structure of feeding behavior - HERE

A.Stricker-Krongrad, C.Burlet, B.Beck(1)
INSERM U-308. MRCA. Equipe de Neurobiologie et Physiologie Expérimentales 38, rue Lionnois F-54000 Nancy France
Life Sciences | Volume 62, Issue 23, 1 May 1998, Pages 2127-2132

...These results indicate that neonatal treatment with MSG induces important changes in feeding patterns and feeding rhythms in the adulthood. These changes might be related to the disappearance of neurotransmitters located in the arcuate nucleus. ...

Effect of dietary monosodium glutamate on trans fat-induced 
nonalcoholic fatty liver disease. HERE

Collison KS(1), Maqbool Z, Saleh SM, Inglis A, Makhoul NJ, Bakheet R, Al-Johi M, Al-Rabiah R, Zaidi MZ, Al-Mohanna FA.
1 Cell Biology and Diabetes Research Unit, Department of Biological and Medical Research, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia.
J Lipid Res. 2009 Aug;50(8):1521-37.

... Conversely, dietary MSG at doses similar to human average daily intake caused hepatic microsteatosis and the expression of beta-oxidative genes. Serum triglyceride, FFA, and insulin levels were elevated in MSG-treated animals. The abdominal cavities of TFA- or MSG-treated animals had increased WAT deposition compared with controls...

Neonatal monosodium glutamate treatment modifies glutamic 
acid decarboxylase activity during rat brain postnatal development - HERE

Mónica Elisa Ureña-Guerrero(a), Silvia Josefina López-Pérez(a), CarlosBeas-Zárate(ab)
a Departamento de Biologı́a Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
b División de Neurociencias, Centro de Investigación Biomédica de Occidente, CIBO-IMSS, Apdo. Postal #4-160, 44421 Guadalajara, Jalisco, Mexico
Neurochemistry International | Volume 42, Issue 4, March 2003, Pages 269-276

Abstract
Monosodium glutamate (MSG) produces neurodegeneration in several brain regions when it is administered to neonatal rats. From an early embryonic age to adulthood, GABA neurons appear to have functional glutamatergic receptors, which could convert them in an important target for excitotoxic neurodegeneration. Changes in the activity of the GABA synthesizing enzyme, glutamic acid decarboxylase (GAD), have been shown after different neuronal insults. Therefore, this work evaluates the effect of neonatal MSG treatment on GAD activity and kinetics in the cerebral cortex, striatum, hippocampus and cerebellum of the rat brain during postnatal development...

Monosodium glutamate-induced oxidative kidney damage and 
possible mechanisms: a mini-review - HERE (full report)

Amod Sharma
Department of Physiology, Siriraj Hospital, Mahidol University, Bangkok, 10700 Thailand
Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002 Thailand
Journal of Biomedical Science. 2015; 22: 93. Published online 2015 Oct 22.

Abstract
Animal studies suggest that chronic monosodium glutamate (MSG) intake induces kidney damage by oxidative stress. However, the underlying mechanisms are still unclear, despite the growing evidence and consensus that α-ketoglutarate dehydrogenase, glutamate receptors and cystine-glutamate antiporter play an important role in up-regulation of oxidative stress in MSG-induced renal toxicity. This review summaries evidence from studies into MSG-induced renal oxidative damage, possible mechanisms and their importance from a toxicological viewpoint.

Stress-induced increase in blood-brain barrier permeability 
in control and monosodium glutamate-treated rats. - HERE

Skultétyová I(1), Tokarev D, Jezová D.
1 Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava.
Brain Res Bull. 1998;45(2):175-8.

Abstract
Glutamate administration in neonatal rats causes reversible changes in blood-brain barrier (BBB) permeability and known neurotoxic lesions. This study was aimed to evaluate whether glutamate administered to neonatal rats influences properties of the developing BBB with consequences on adult BBB function. .. BBB vulnerability in glutamate-treated rats during stress exposure was increased in the hypothalamus and decreased in the brain stem.

Monosodium-l-glutamate-induced convulsions—I. Differences in 
seizure pattern and duration of effect as a function of age in rats - HERE

Jorge Arauz-Contreras, AlfredoFeria-Velasco
Division of Neurobiology, Unidad de Investigacion Biomedica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico
General Pharmacology: The Vascular System | Volume 15, Issue 5, 1984, Pages 391-395

Abstract
1. Convulsive activity in 3, 10, 60 and 180-day old Sprague-Dawley rats was studied following the i.p. administration of 4 mg g−1 of commercial MSG.

2. The latency period increased with the age of the animals while the duration of the convulsive period was longer in younger animals and shorter in 60-day old rats.

3. Convulsions were predominantly tonic in 3 and 10-day old rats, tonic-clonic in 60-day old rats, and predominantly clonic in 180-day old animals.

4. The severity of the convulsions and death incidence increased progressively with age.

5. Animals injected either with sodium chloride equimolar to MSG or physiological saline solution showed no convulsive activity.

6. The effects of MSG without trace metals were no different from those produced by commercial MSG.

A delayed LH/FSH rise after gonadectomy and a delayed serum TSH 
rise after thyroidectomy in monosodium-L-glutamate (MSG)-treated rats. HERE

Greeley GH Jr, Nicholson GF, Kizer JS.
Brain Res. 1980 Aug 11;195(1):111-22.

Abstract
The serum LH and FSH rise after gonadectomy and the serum TSH rise after thyroidectomy were examined in rats that received monosodium-L-glutamate (MSG) as neonates. The rise in serum gonadotrophins after gonadectomy was significantly delayed in both adult and peripubertal MSG-treated rats when compared to control castrates. Serum LH and FSH levels, however, eventually achieved levels in MSG-treated rats that were not significantly different than those of controls. The serum TSH rise after thyroidectomy was significantly delayed in adult female MSG-treated rats, but not in prepubertal female MSG-treated rats. Pituitary responsiveness to both exogenous LH-RH and TRH was unaffected by neonatal MSG treatment, with one exception: pituitary responsiveness to HL-RH of orchidectomized peripubertal males was blunted significantly. The results are discussed in terms of the possible neurotoxic effects of neonatal MSG treatment, as well as the altered hypothalamic sensitivity to gonadal steroids.

Neonatal monosodium glutamate differentially alters two models of behavioral
 activity in conjunction with reduced hypothalamic endorphins - HERE

R.J.Katz
Department of Psychology, The Johns Hopkins University, 34th and Charles Sts., Baltimore, MD 21218 USA
Physiology & Behavior | Volume 31, Issue 2, August 1983, Pages 147-151

...These findings indicate that neonatal MSG has long-term behavioral and neurological consequences, that some changes occur within behaviorally discrete systems, and that they may be associated with functional alterations within endogenous opioid systems, inter alia.

Sex-specific impairment in sexual and ingestive behaviors 
of monosodium glutamate-treated rats - HERE

Yuh-Man Sun∗ Hseng-Kuang Hsu∗ Sheng-I Lue∗ Ming-Tsung Peng†
∗ Department of Physiology, Kaohsiung Medical College, Kaohsiung 807, Taiwan, Republic of China
† Department of Physiology College of Medicine, National Taiwan University, Taipei 100, Taiwan, Republic of China
Physiology & Behavior | Volume 50, Issue 5, November 1991, Pages 873-880

Abstract
L-monosodium glutamate (MSG) (4 mg/g b.wt.) was injected subcutaneously to pups on days 1 and 3. At age 3.5 months, sexual and ingestive behaviors were observed. Neonatal MSG treatment resulted in severe and widespread neuron destruction in the basomedial hypothalamus of both sexes, but only superchiasmatic nucleus in male rats. A decline in sexual behavior was also observed. Serum levels of testosterone and dihydrotestosterone in male rats as well as serum level of progesterone in female rats were decreased. Ovariectomized MSG-treated female rats injected with estradiol benzoate followed by progesterone showed a dramatic improvement in sexual behavior, whereas castrated MSG-treated male rats injected with testosterone propionate did not meliorate the decline of sexual behavior. Neonatal MSG treatment also induced reductions of body weight in male rats, higher diurnal percentages of food and water intake in male rats than in female rats, and a decline of water-to-food ratio. These observations suggest that neonatal male rats show higher susceptibility to glutamate-induced dysfunction of sexual and ingestive behaviors than females. Our findings also suggest a sex difference in the mechanism of dysfunction of sexual behavior, i.e., decreased copulatory activity in male rats is mainly due to CNS damage, in contrast to decreased blood progesterone level in female rats.

Neonatal exposure to monosodium glutamate 
disrupts place learning ability in adult rats - HERE

E.Olvera-Cortés(a), M.A.López-Vázquez(b), C.Beas-Zárate(c), I.González-Burgos(b)
a Laboratorio de Neurofisiología Experimental, CIBIMI, IMSS. Morelia, 58000 Mich, Mexico
b Laboratorio de Psicobiología, CIBIMI, IMSS. Morelia, 58000 Mich, P.O. Box 7-70, 58261, México
c Laboratorio de Neurobiología Celular y Molecular, CIBO; IMSS/Departamento de Biología Celular y Molecular, CUCBA; U. de G. Guadalajara, 44340 Jal. México
Pharmacology Biochemistry and Behavior | Volume 82, Issue 2, October 2005, Pages 247-251

Abstract
The activation of glutamatergic NMDA receptors of the hippocampus is closely associated with expression of place learning. Neonatal exposure to monosodium glutamate leads to abnormal expression of NMDA receptor subunits in the hippocampus, but its effect on place learning is unknown...

These results show that both place learning acquisition and retrieval abilities in mature rats are impaired by neonatal treatment with monosodium glutamate. These findings may be related to the abnormal expression of NMDA receptor subunits in the hippocampus...

Monosodium glutamate: Acute and chronic effects on rhythmic growth hormone and prolactin secretion, and somatostatin in the undisturbed male rat - HERE

L.Cass Terry, Jacques Epelbaum, Joseph B.Martin
Department of Experimental Medicine and the Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
Brain Research | Volume 217, Issue 1, 27 July 1981, Pages 129-142

...These results suggest: (1) neonatally administered MSG causes a marked disturbance in episodic GH and PRL secretion in adult rats; (2) MSG induces a decrease in hypothalamic SRIF and possibly GH-releasing factor; and (3) the acute effects of MSG on GH and PRL may be due to the inhibition and/or excitation of a complex neuronal network involving monoaminergic and peptidergic systems.

Monosodium glutamate: increased neurotoxicity after 
removal of neuronal re-uptake sites - HERE

Christer Köhler(a,b) Robert Schwarcz(a,b)
a ASTRA Research Laboratories, ASTRA Läkemedel AB, Södertälje, Sweden
b Maryland Psychiatric Research Center, P.O. Box 3235, Baltimore, Md. 21228, U.S.A.
Brain Research | Volume 211, Issue 2, 4 May 1981, Pages 485-491

Abstract
Microinjections of monosodium glutamate (MSG; 300 μg/0.5 μl) into the hippocampus of the adult rat result in only marginal damage to local neurons. Perforant path transections, removing glutamatergic afferents to hippocampal granule cells, make the latter markedly more vulnerable to a subsequent MSG injection. The principle of modulating toxic effects of MSG by interfering with its neurotransmitter role may have significant impact on our understanding of human neurodegenerative disorders.

Effects of neonatal treatment with monosodium glutamate 
on circadian locomotor rhythm in the rat - HERE

Susumu Miyabo(1), Itaru Yamamura(1), Eiichi Ooya(1), Naoki Aoyagi(1) Yasuhiro Horikawa(1) Shinji Hayashi(2)
1 Department of Internal Medicine, Fukui Medical School, Fukui Prefecture, PC 910-11, Tokyo Metropolitan Institute for Neurosciences, Fuchu City, Tokyo, PC-183 Japan
2 Department of Anatomy and Embryology, Tokyo Metropolitan Institute for Neurosciences, Fuchu City, Tokyo, PC-183 Japan
Brain Research | Volume 339, Issue 2, 29 July 1985, Pages 201-208

Abstract
In order to study the effects of treatment with monosodium glutamate (MSG) during the neonatal period on the intrinsic circadian timekeeping system in rats, the locomotor activity of blinded MSG-treated and control (saline-treated) rats was analyzed with power spectral analysis and cross-correlation. In contrast to a robust free-running circadian rhythm in the control rats, a significant shortening of the circadian period and rapid decomposition into ultradian components were noted in the MSG-treated rats. Computer-assisted stereometry of the hypothalamic nuclei revealed that, in addition to the well-known severe damage in the arcuate nuclei (ARC), the volumes of the suprachiasmatic nuclei (SCN) and ventromedial hypothalamic nuclei (VMH) were also reduced significantly in the MSG-treated rats. Although no gross histological damage was apparent in either the SCN and VMH, neonatal MSG treatment appears to impair the function of SCN to integrate many minor oscillations in the brain into a single, definite and precise circadian period.

Reduced norepinephrine turnover in mice with 
monosodium glutamate-induced obesity - HERE

Toshihide Yoshida, Hitoshi Nishioka, Yoshio Nakamura, Motoharu Kondo
First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kamikyo-ku, Kyoto 602, Japan.

Metabolism | Volume 33, Issue 11, November 1984, Pages 1060-1063

Abstract
The disappearance of norepinephrine from the heart, interscapular brown adipose tissue (BAT), and pancreas has been examined in mice with monosodium glutamate (MSG)-induced obesity and in untreated controls. MSG-treated mice became obese in the absence of increased food intake and their core temperature was significantly lower compared to control mice. The rate of norepinephrine turnover following blockade of norepinephrine synthesis with α-methylpara-tyrosine was significantly slower in heart and interscapular BAT of these mice than in untreated controls, but MSG had no effect on the pancreas. It is suggested that reduced norepinephrine turnover may be a major factor in the development of obesity after neonatal administration of MSG.

Defective thermoregulatory thermogenesis in monosodium 
glutamate-induced obesity in mice. HERE

Moss D, Ma A, Cameron DP.
Metabolism. 1985 Jul;34(7):626-30.

...The following conclusions were reached: (1) MSG-treated mice have defective cold induced thermogenesis, indirect evidence suggests this results from impaired activation of thermogenic mechanisms in BAT; (2) the defect responsible for this lies extrinsic to BAT; and (3) the quantitative significance of defective thermoregulatory thermogenesis for the development of obesity in these mice is uncertain...

Cafeteria feeding promotes diet-induced thermogenesis 
in monosodium glutamate-treated mice - HERE

D.Moss, A.Ma, D.P. Cameron
Department of Diabetes and Endocrinology, Princess Alexandra Hospital, Brisbane, Q.4102 Australia.
Metabolism | Volume 34, Issue 12, December 1985, Pages 1094-1099

...There was a significant weight gain in cafeteria fed MSG-treated mice but not in cafeteria fed saline-treated mice...

Acute and long lasting neurochemical effects of monosodium
 glutamate administration to mice. HERE

Ralph Dawson Jr
Division of Toxicology The Johns Hopkins University Baltimore, Maryland 21205, USA
Neuropharmacology | Volume 22, Issue 12, Part 2, December 1983, Pages 1417-1419

...These findings show that the acute administration of MSG results in alterations in hypothalamic monoamine metabolism which may be related to the neuroendocrine consequences of excitatory amino acid administration.

Obesity in exercising, hypophagic rats treated with monosodium glutamate - HERE

Michael M.Nikoletseas
Department of Psychology, Program of Psychobiology, Rutgers — The State University, New Brunswick, NJ 08903 USA
Physiology & Behavior | Volume 19, Issue 6, December 1977, Pages 767-773

Abstract
Two experiments employing 32 female and 28 male rats, respectively, were performed in order to assess the effects of monosodium glutamate (MSG) on locomotor activity levels, as well as the consequences of such activity on the known obesity that follows MSG injections. In both sexes activity levels of MSG-treated animals were not significantly different from those of controls. Obesity developed in both sexes despite normal activity levels and hypophagia. Vaginal smears and autopsy data indicated that the female reproductive system was severely disturbed while no apparent anomalies were noted in the males. Skeletal growth arrest was evident in both sexes at 130 days of age. The data are interpreted in the context of the hypopituitarism of the MSG animal. A sexual dimorphism in both MSG and intact animals was noted as regards the food intake-activity interaction: spontaneously active females ate significantly more than nonactive females, while there was no such difference in males.

Modulation of intracellular gene expression toward Th2 predominant 
profile by monosodium glutamate in Jurkat cell line - HERE

J.Shin(a), Y.Seo(b), N.Cho(c), G.Noh(d)
a Pediatric Allergy, Joey Children's Hospital, Taejeon, Republic of Korea
b Molecular Immunology, Seoul Allergy Research Institute, Food BioTech Co. Ltd, Seoul, Republic of Korea
c Microarray & Molecular Immunology, Seoul Allergy Research Institute, Food BioTech Co. Ltd, Seoul, Republic of Korea
d Allergy & Clinical Immunology, Seoul Allergy Clinic, Seoul, Republic of Korea
Journal of Allergy and Clinical Immunology | Volume 113, Issue 2, Supplement, February 2004, Page S214

...Conclusions
MSG modulated intracellular gene expression toward Th2 predominant profile and MSG may have immunomodulatory effects of Th2-deviation to be prone to allergic status...

The monosodium glutamate symptom complex: Assessment 
in a double-blind, placebo-controlled, randomized study 1 - HERE

MD, FRCPC William H.Yang(a), MD, FRCPC Michel A.Drouin(a), MSc Margaret Herbert(b) PhD Yang Maob(c) MDCM,FRCPC JacobKarsh(a)
a Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
b Laboratory Center for Disease Control, Health Canada, Ottawa, Ontario, Canada
c Bureau of Chronic Disease Epidemiology, Health Canada, Ottawa, Ontario, Canada
Journal of Allergy and Clinical Immunology | Volume 99, Issue 6, Part 1, June 1997, Pages 757-762

Results: Sixty-one subjects entered the study. On initial challenge, 18 (29.5%) responded to neither MSG nor placebo, 6 (9.8%) to both, 15 (24.6%) to placebo, and 22 (36.1%) to MSG (p=0.324). Total and average severity of symptoms after ingestion of MSG (374 and 80) were greater than respective values after placebo ingestion (232 and 56; p=0.026 and 0.018, respectively). Rechallenge revealed an apparent threshold dose for reactivity of 2.5 gm MSG. Headache (p<0.023), muscle tightness (p<0.004), numbness/tingling (p<0.007), general weakness (p<0.040), and flushing (p<0.016) occurred more frequently after MSG than placebo ingestion.

Conclusions: Oral challenge with MSG reproduced symptoms in alleged sensitive persons. The mechanism of the reaction remains unknown, but symptom characteristics do not support an IgE-mediated mechanism. According to Food and Drug Administration recommendations, the symptoms, originally called the Chinese restaurant syndrome, are better referred to as the MSG symptom complex. (J Allergy Clin Immunol 1997;99:757-62.)

Studies on the effects of monosodium glutamate on hepatic microsomal lipid peroxidation, calcium, ascorbic acid and glutathione and its dependent enzymes in adult male mice - HERE

P.Choudhary, V.B.T.Malik, S.Puri, P.Ahluwalia
Toxicology Letters | Volume 89, Issue 1, December 1996, Pages 71-76

...These observations suggested that MSG at dose levels above 4 mg/g body weight induced oxidative stress in hepatic microsomes...

The Neonatal Treatment of Rats with Monosodium Glutamate 
Induces Morphological Changes in the Subfornical Organ - HERE

P Pesini, J L Rois, L Menéndez, S Vidal
Article in Anatomia Histologia Embryologia 33(5):273-7 · November 2004 

Abstract
The parenteral administration of monosodium glutamate (MSG) to neonatal rats induces specific lesions in the central nervous system that lead to a well characterized neuroendocrinological dysfunction. Additionally, it has been shown that MSG-treated rats present a blunted blood pressure response to the injection of nitric oxide synthase inhibitors. Recently, a similar cardiovascular alteration has been reported after the electrolytic lesion of the anteroventral region of the third ventricle affecting the connections of the subfornical organ (SFO). We hypothesized that the treatment of neonatal rats with MSG could affect the nitrergic cells of the SFO. In the present work, we have looked for alterations in the NADPH-diaphorase activity (a commonly used marker for nitrergic neurons) in the SFO of MSG-treated rats of either sex and at two different ages. Our results shown that the treatment of neonatal rats with MSG induced a substantial reduction in the volume of the SFO and in the number of its nitrergic cells with regard to control animals. These findings suggest that the SFO could be implicated in some of the cardiovascular alterations observed in MSG-treated rats.

EFFECT OF MONOSODIUM GLUTAMATE ON THE ENDOCRINE GLANDS
AND ON THE REPRODUCTIVE FUNCTION OF THE RAT - HERE (pdf)

GIAN PAOLO TRENTINI, M.D., L.D., ANNIBALE BOTTICELLI, M.D., L.D., AND CATERINA SANNICOLA BOTTICELLI, D.Sc.
Institute of Pathological Anatomy, University of Modena, 41100 Modena, Italy
Fertility and Sterility | Vol 25, No 6. June 1974

Lesions can be produced in the hypothalamus of several species of experimental animals by means of the chemical agent, monosodium-L-glutamate (MSG). This finding is of great interest because this region controls the production of neurohypophyseal hormones and of releasing and inhibiting factors regulating the secretion of adenohypophyseal tropins. Recently, Redding et a}1 reported that
MSG injected subcutaneously in neonatal female and male rats retarded growth and reduced the weight of several endocrine organs when the rats reached 110 days of age. In particular, there was a marked decrease in growth hormone and luteinizing hormone content of the anterior pituitary and extensive damage to ovaries and testes. The ovaries became atrophied with many atretic follicles. However, the fertility of the animals was not tested and the histomorphology of the hypothalamus and
endocrine glands was not studied.

...Therefore, after finding the pituitary concentration of trophic hormones depressed in 40-day-old rats after multiple MSG injections in infancy, we can infer the existence of an MSG-induced hypothalamic defect which especially concerns the arcuate nucleus and is primarily reflected in the pituitary gland, as demonstrated by Redding et aU On the other hand, Olney(6) maintains that Adamo and Ratner's(2) conclusion that MSG lacks any effect on the reproductive function of the rat is probably a misinterpretation of insufficient data. We cannot agree with Olney on this. Insofar as the stunting of the endocrine organs is concerned, our results agree with those of Olney and colleagues (in press) and of Redding et al/ but they emphasize the complete normality of the reproductive function of MSG-treated rats.

Biochemical Changes in the Malnourished Rats Serum and 
Liver Exposed to Dietary Monosodium Glutamate - HERE (pdf)

Babawande A. Origbemisoye (Department of Food Science and Technology, Federal University of Technology, Akure, Ondo State, Nigeria.)
Badiu A. Akinbode (Department of Food Science and Technology, Federal University of Technology, Akure, Ondo State, Nigeria.
Ganiyat A. Oparemi (Department of Biochemistry, Faculty of Basic Medical Sciences, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
European Journal of Nutrition & Food Safety | 2019 Volume 10 (issue 2)

... Malnourished rats showed significant decrease in body weight losing 48 grams after 28 days compared to malnourished and normal rats fed with MSG which recorded significant increase in body weight after 28 days adding 26 g and 42 g respectively.

Neuroendocrine, metabolic, and immune functions during the acute phase response of inflammatory stress in monosodium L-glutamate-damaged, hyperadipose male rat. HERE

Castrogiovanni D(1), Gaillard RC, Giovambattista A, Spinedi E.
1 Neuroendocrine Unit, IMBICE (CONICET-CICPBA), La Plata, Argentina.
Neuroendocrinology. 2008;88(3):227-34.

...These data indicate that metabolic and neroendocrine-immune functions are altered in MSG-damaged rats. Our study also suggests that the enhanced corticotrope-corticoadrenal activity in MSG animals could be responsible, at least in part, for the immune and metabolic derangements characterizing hypothalamic obesity.

Neonatal Treatment with Monosodium Glutamate 
Increases Plasma Corticosterone in the Rat - HERE (pdf available)

Miriam Sterman Dolnikoff, Claudio E Kater, Mizue Egami, Andrade I S
Neuroendocrinology 48(6):645-9 · January 1989

... These data suggest that the central lesions produced by MSG treatment disrupt the regulation of the hypothalamic-pituitary-adrenal axis.

Prediabetic changes in gene expression induced by aspartame 
and monosodium glutamate in Trans fat-fed C57Bl/6 J mice. HERE

Collison KS(1), Makhoul NJ(1), Zaidi MZ(1), Inglis A(1), Andres BL(1), Ubungen R(1), Saleh S(1), Al-Mohanna FA(2).

1 Diabetes Research Unit, Department Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh 11211, Saudi Arabia.
2 Diabetes Research Unit, Department Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh 11211, Saudi Arabia ; College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia.
Nutr Metab (Lond). 2013 Jun 19;10:44.

... CONCLUSION:
The combination of ASP and MSG may significantly alter adiposity, glucose homeostasis, hepatic and adipose tissue gene expression in TFA-fed C57Bl/6 J mice.

Cognitive and biochemical effects of monosodium glutamate and aspartame, 
administered individually and in combination in male albino mice - HERE

Gasem M.Abu-Taweel(a), Zyadah M.A.(a), Jamaan S.Ajarem(b), Mohammad Ahmad(c)
a Department of Biology, Dammam University, Saudi Arabia
b Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
c Department of Medical Surgical Nursing, College of Nursing, King Saud University, Riyadh, Saudi Arabia
Neurotoxicology and Teratology | Volume 42, March–April 2014, Pages 60-67

Abstract
... Both MSG and ASM individually as well as in combination had significant disruptive effects on the cognitive responses, memory retention and learning capabilities of the mice in the order (MSG + ASM) > ASM > MSG. Furthermore, while MSG and ASM individually were unable to alter the brain neurotransmitters and the oxidative stress indices, their combination dose (MSG + ASM) decreased significantly the levels of neurotransmitters (dopamine and serotonin) and it also caused oxidative stress by increasing the lipid peroxides measured in the form of thiobarbituric acid-reactive substances (TBARS) and decreasing the level of total glutathione (GSH). Further studies are required to evaluate the synergistic effects of MSG and ASM on the neurotransmitters and oxidative stress indices and their involvement in cognitive dysfunctions.

Neonatal monosodium glutamate treatment causes obesity, diabetes, 
and macrovesicular steatohepatitis with liver nodules in DIAR mice. HERE

Tsuneyama K(1), Nishida T, Baba H, Taira S, Fujimoto M, Nomoto K, Hayashi S, Miwa S, Nakajima T, Sutoh M, Oda E, Hokao R, Imura J.
1 Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
Journal of Gastroenterology and Hepatology Foundation | 2014 Sep;29(9):1736-43.

...CONCLUSIONS:
DIAR-MSG had NASH-like liver pathology and liver nodules typically associated with MS symptoms. DIAR-MSG provides a valuable animal model to analyze NASH pathogenesis and carcinogenesis.

The relation between monosodium glutamate inducing brain damage, and body weight, food intake, semen production and endocrine criteria in the fowl. HERE

Robinzon B, Snapir N, Perek M.
Poult Sci. 1975 Jan;54(1):234-41.

Various dosages of monosodium glutamate (M.S.G.) were injected to 5 day old male chicks. Body weights, food intake, rate of obesity, semen production, some endocrine criteria and brain pathology were studied til 235 days post injection. All M.S.G. treated birds showed brain damage in the rotundus nuclei, and in the area located dorsolaterally to the ventromedial hypothalamic nuclei (V.M.H.). In some of the M.S.G. treated birds, additional brain regions were damaged, i.e. V.M.H., mammillary nuclei, dorsomedial anterior nuclei, ovoid nuclei, subrotundus nuclei, archistriatum and lateral forebrain bundles. Some of the M.S.G. treated birds showed marked abdominal fat deposition or low spermatozoan motility. It was impossible to attribute these changes to the dosage of M.S.G. injected. No significant differences were found in these parameters between the treated birds and the saline injected ones. When the M.S.G. treated birds were categorized on the basis of brain damage in specific sites, the following was observed: 1) Birds with V.M.H. damage accumulated significant larger amounts of fat in the abdominal adipose tissue than the rest of the M.S.G. treated birds. 2) Those M.S.G. treated birds, showing brain damage in their mammillary nuclei, produced semen of a very low spermatozoan motility rate as compared to the rest of the M.S.G. treated birds and the controls.

Brain damage in the male domestic fowl treated with monosodium glutamate. HERE

Snapir, N. ;  Robinzon, B. ;  Perek, M.
Dept. Animal Hygiene and Poultry Science, Faculty of Agriculture, Hebrew Univ. Jerusalem, Rehovot, Israel.
Journal article : Poultry Science 1971 Vol.50 No.5 pp.1511-1514

Abstract : Single or daily subcutaneous injections of 1 or 4 mg monosodium glutamate (MSG)/g bodyweight or saline (controls) were given to 5-day-old male New Hampshire X White Leghorn chickens and after 40 days the brains were studied histologically. Chickens given MSG had brain damage in the area of the ventromedial hypothalamus but controls had no brain damage. There was no significant difference between controls and experimental chickens in feed intake or bodyweight.-S. D.
Age Dependent Sensitivity to Monosodium Glutamate 
Inducing Brain Damage in the Chicken - HERE (pdf)

Robinzon B.Snapir, N.Perek M.
Department of Poultry Science and Animal Hygeine, The Hebrew University of Jerusalem, Faculty Agriculture, P.O. Box 12, Rehovot, Israel
Poultry Science | Volume 53, Issue 4, 1 July 1974, Pages 1539-1542

...It is suggested that the decrease in the sensitivity of the domestic fowl to M.S.G. inducing brain damage is age dependent being probably as a result of the development of a blood-brain-barrier to glutamic acid.

Monosodium Glutamate, a Food Additive, Induces Depressive-like and 
Anxiogenic-like Behaviors in Young Rats. HERE (pdf available)

Caroline B.Quines(a), Suzan G.Rosa(a), Juliana T.Da Rocha(a), Bibiana M.Gai(a), Cristiani F.Bortolatto(a), Marta Maria M.F.Duarte(b), Cristina W.Nogueira(a)
a Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil
b Departamento de Ciências da Saúde, Universidade Luterana do Brasil, Santa Maria, Rio Grande do Sul, Brazil
Life sciences 107(1) · May 2014

... Significance
In conclusion MSG-treated rats are more susceptible to develop anxiogenic- and depressive-like behaviors, which could be related to a dysfunction in the serotonergic system.

Studies on effect of monosodium glutamate (MSG) on various fractions of lipids and certain carbohydrate metabolic enzymes in liver and blood of adult male mice - HERE

V.B.T.Malik, P.Ahluwalia
Department of Biochemistry, Punjab University, Chandigarh-160 014, India
Toxicology Letters | Volume 74, Issue 1, October 1994, Pages 69-77

...All these observations are suggestive of the fact that carbohydrate metabolism is shifted towards lipogenesis and hence leads to hyperlipidemia.

Neonatal monosodium glutamate administration alters
 noradrenergic measures in the brainstem of the mouse - HERE

Ralph Dawson Jr., Zoltan Annau
Neurotoxicology Program, Department of Environmental Health Sciences The Johns Hopkins University, Baltimore, MD 21205 USA
Brain Research Bulletin | Volume 15, Issue 2, August 1985, Pages 117-121

...The results suggest that MSG-induced damage to the arcuate nucleus produces selective alterations in brainstem NE systems. These alterations may reflect the toxic action of MSG on the opiomelanocortin neurons of the arcuate nucleus or other descending systems that are damaged by MSG. The loss of the descending opiomelanocortin input to the brainstem could result in these types of neurochemical consequences since the pharmacologie action of opiate drugs results in a selective enhancement of brainstem NE turnover in rodents.

Effect of oral monosodium glutamate on glutamic acid levels in the nucleus arcuatus of the hypothalamus and on serum osmolality of adult and infant mice - HERE (pdf Available)

L.Airoldi, M.Bonfanti, P.Ghezzi, M.Salmona, S.Garattini
Istituto di Ricerche Farmacologiche “Mario Negri”, Via Eritrea, 62, 20157 MilanItaly
Toxicology Letters | Volume 7, Issue 2, December 1980, Pages 107-111

...Serum osmolality, measured after oral MSG, was elevated in infant mice but was unaffected in adults.
Studies on reproductive endocrine function in rats treated 
with monosodium l-glutamate early in life - HERE

Yoshimasa Matsuzawa,Shinobu Yonetani, Yutaka Takasaki, seinosuke I wata, Seikichi Sekine
Life Science Laboratory, Central Research Laboratories, Ajinomoto Co., Inc., 214, Maeda-cho, Totsuka-ku, Yokohama-shi, Kanagawa-kenJapan
Toxicology Letters | Volume 4, Issue 5, November 1979, Pages 359-371

Abstract
Repeated s.c. injections of high doses of monosodium-l-glutamate (MSG) to neonatal female rats caused precocious puberty, disturbed oestrous cycle and small ovaries and pituitary. Pituitary LH and FSH were low but the basal serum levels were unchanged from control values. Serum E2 level was significantly low in the early stages. Cyclic regulation of gonadotrophin release and follicular maturation was inadequate. Pituitary-gonadal function in males was less affected. Females treated with high doses of MSG as infants showed normal onset of puberty and regular oestrous cycles, but subsequent earlier oestrous cycle irregularity was observed than in controls. Gonadal weights in both sexes were slightly reduced. Serum hormone levels and the pituitary contents were not changed from those of controls except for reduced FSH. Males and females, given subneurotoxic doses of MSG, or fed large amounts of MSG ad libitum, presented no abnormalities. MSG administration therefore induces marked abnormalities in reproductive endocrine function after maturation only when injected parenterally, early in postnatal life, in repeated, very large doses.

Neuropeptide Y in the specific hypothalamic nuclei of rats 
treated neonatally with monosodium glutamate - HERE

Mitsushi Abe, Masayuki Saito(1)Takashi Shimazu
Department of Medical Biochemistry, School of Medicine, Ehime University, Shigenobu, Ehime 791-02, Japan
Brain Research Bulletin | Volume 24, Issue 2, February 1990, Pages 289-291

Abstract
Neuropeptide Y (NPY) concentration was determined by radioimmunoassay in selected hypothalamic regions microdissected from fresh brain slices of rats treated neonatally with monosodium glutamate (MSG). Fourteen weeks after MSG treatment, significant decreases in NPY concentration were found in the paraventricular nucleus (PVN) and arcuate nucleus (ARH), while there was no appreciable change in the ventromedial nucleus (VMH) and lateral area (LH). The decrease in NPY in the ARH-PVN system may contribute to the endocrine and metabolic disturbances seen in MSG-treated animals.

Effect of monosodium glutamate on lipid peroxidation and certain antioxidant 
enzymes in cardiac tissue of alcoholic adult male mice - HERE (pdf available)

Kuldip Singh, Pushpa Ahluwalia
Journal of cardiovascular disease research 3(1):12-8 · March 2012 

...These observations suggested that oral ingestion of MSG at dose levels of 4 mg/g body weight and above with and without alcohol increased the oxidative stress and thereby, could act as an additional factor for the initiation of atherosclerosis.

Effects of neonatal treatment with MSG (Monosodium glutamate) 
on hypothalamopituitary-thyroid axis in adult male rats - HERE (pdf)

B. Miskowiak and M. Partyka
Department of Histology and Embryology, K. Marcinkowski University of Medical Sciences, Poznan, Poland
Histol Histopath (1 993) 8: 731 -734

...The results obtained suggest that the rat hypothalamic centres involved in regulation of the pituitary-thyroid axis are slightly affected by neonatal MSG treatment.

Growth, endocrinological and behavioral deficits after monosodium l-glutamate in the 
neonatal rat: possible involvement of arcuate dopamine neuron damage - HERE

Charles B.Nemeroff, Lester D.Grant, Garth Bissette, Gregory N.Ervin, Lindy E.Harrell, Arthur J.Prange Jr.
The Neurobiology Program, Departments of Psychiatry and Anatomy, Biological Sciences Research Center, University of North Carolina, School of Medicine, Chapel Hill, NC 27514, U.S.A.
Psychoneuroendocrinology | Volume 2, Issue 2, 1977, Pages 179-196

Abstract
(1) The syndrome induced by the systemic administration of monosodium l-glutamate (MSG) to neonatal rats was investigated. (2) Animals receiving five injections of 4 mg/g of MSG (MSG V) in the first 10 days of life showed, as adults, growth, endocrinological, and behavioral abnormalities, whereas those receiving one injection (MSG I) showed few of the characteristic symptoms associated with neonatal MSG treatment. (3) MSG V females were markedly hypoactive ten weeks after weaning as measured in circular photocell activity cages in the dark part of the rats' day-night cycle. (4) MSG V rats were extremely stunted and obese (as determined by the Lee index) but appeared normophagic. (5) A previously unreported aspect of MSG toxicity, tail automutilation, occurred in a large proportion of MSG I and MSG V animals, with the highest incidence in MSG V females. (6) MSG V animals were hypothyroid as measured by radioimmunological determinations of serum triiodothyronine (T3) and free thyroxine index (FTI). In addition, MSG V females had smaller ovaries, uteri, and pituitaries when compared with saline-treated controls. (7) Histochemical examination of the hypothalamic arcuate area revealed a marked loss of dopaminergic perikarya in MSG V, but not MSG I animals; other catecholamine systems appeared intact. This raises the possibility that damage to the tubero-infundibular dopamine system may contribute to endocrinological and other deficits observed after neonatal MSG treatment.

Behavioural studies in rats treated with monosodium l-glutamate 
during the early stages of life - HERE

Seinosuke Iwata, Masamichi Ichimura, Yoshimasa Matsuzawa, Yutaka Takasaki, Makoto Sasaoka
Life Science Laboratory, Central Research Laboratories, Ajinomoto, Co., Inc., 214, Maeda-cho, Totsuka-ku, Yokohama-shi, Kanagawa-kenJapan
Toxicology Letters | Volume 4, Issue 5, November 1979, Pages 345-357

Abstract
Behavioural observations were made on rats given repeated high, subneurotoxic doses of monosodium l-glutamate (MSG), or large amounts of MSG in the diet, during the early stages of life. Multiple injections of 4 g/kg MSG to neonates caused low grip strength, hypoactivity, changes of spontaneous motor activity pattern in a day, deficit of learning ability and tail mutilation. The same treatment at the infant stage resulted in only slight behavioural abnormalities at a later stage of life, or yielded nothing at all. Administration of subneurotoxic doses either by s.c. injection or forced intubation, or at high levels in a diet provided ad libitum, were without behavioural effect. Adverse behavioural effects were not induced when the brains were free from histological evidence of damage.
(bearing in mind this is a study by an industry leader (Ajinomoto) in the Glutamate business)


Divergent effects of acute and chronic monosodium l-glutamate treatment 
on the anterior and posterior parts of the arcuate nucleus - HERE

L.Seress
Department of Physiology, University Medical School Pécs, Hungary
Neuroscience | Volume 7, Issue 9, September 1982, Pages 2207-2216

Abstract
Young albino rats were injected with either single or repeated doses of 0.1–6.0 mg/g body weight of monosodium l-glutamate between the ages of 2 and 40 days. The smallest, single effective dose was 0.25 mg/g body weight administered during the first week of life. The sensitivity to monosodium l-glutamate decreased with age. Monosodium l-glutamate caused nuclear pyknosis and edematous swelling of neurons in the anterior part of the arcuate nucleus which is located at the level of the ventromedial nucleus. These effects resulted in a reduction of neurons in this region. All of the doses used were ineffective in producing necrosis or cell death in the posterior part of the arcuate nucleus which is found at the level of the premamillary nuclei. The number of neurons in the arcuate nucleus of control animals was 46,500 with a neuron/glia ratio of 1.22. The anterior part of the arcuate nuclus had 55% of the neurons.

Adult animals with an 80–90% loss of neurons in the anterior part of arcuate nucleus showed marked adiposity, hypoactivity, decreased body length, tail automutilation and reduced endocrine organ weight. The histological appearance of the ovaries, testes and pituitary glands was normal. The sexual behavior of these rats was normal, but the females were not fertile.

The results of this study indicate that monosodium l-glutamate has a regional effect on the arcuate nucleus. These data also indicate that the majority of the neurons in the anterior arcuate region do not play a definitive role in the basal regulation of gonadotrophic hormones.

Monosodium glutamate neurotoxicity: A sex-specific impairment of 
blood pressure but not vasopressin in developing rats - HERE

Richard W.Clough, Paul F.Aravich, Celia D.Sladek
a Department of Neurobiology and Anatomy University of Rochester School of Medicine and Dentistry, Rochester, NY 14642 U.S.A.
b Department of Neurology University of Rochester School of Medicine and Dentistry, Rochester, NY 14642 U.S.A.
Brain Research Bulletin | Volume 17, Issue 1, July 1986, Pages 51-58

...MSG treatment produced several features characteristic of the MSG-toxicity syndrome, including obesity, anterior pituitary dysgenesis and hypogonadism... In contrast, neonatal treatment with MSG altered SBP in a sex dependent manner. Female MSG-treated rats, unlike male MSG-treated rats, exhibited consistent systolic hypotension when compared with the NaCl-treated or non-treated control rats at 6, 9 and 12 weeks of age. Despite this chronic hypotension in MSG-treated female rats, heart rate was not altered and serum AVP was not elevated. These observations suggest a resetting of the baroreflex, attributable to neonatal administration of MSG.

Monosodium glutamate neurotoxicity increases beta amyloid in the 
rat hippocampus: A potential role for cyclic AMP protein kinase - HERE

Abeer E.Dief(a), Eman S.Kamha(b), Azza M.Baraka(c), Amany K.Elshorbagy(a)
a Department of Physiology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
b Department of Medical Biochemistry, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
c Department of Clinical Pharmacology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
NeuroToxicology | Volume 42, May 2014, Pages 76-82

Highlights
Glutamate excitotoxicity plays a role in pathogenesis of Alzheimer's disease (AD).
Monosodium glutamate (MSG) treatment increased β-amyloid in rat hippocampus, similar to what occurs in AD.
Hippocampal AMPK was decreased by MSG, and rescued by the AMPK agonist Pioglitazone, with reduction in β-amyloid.
This data suggests that AMPK reduction and β-amyloid accumulation contribute to MSG neurotoxicity.
Further research should explore whether other AD features can be elicited by MSG treatment, e.g. tau phosphorylation.

Mechanisms underlying hypertriglyceridemia in rats with monosodium
 l-glutamate-induced obesity: Evidence of XBP-1/PDI/MTP axis activation - HERE

Lucas Martins França(a), Larissa Nara Costa Freitas(a),Vinicyus Teles Chagas(a), Caio Fernando Ferreira Coêlho(a), Wermerson Assunção Barroso(a), Graciomar Conceição Costa(b), Lucilene Amorim Silva(b), Victor Debbas(c), Francisco Rafael Martins Laurindo(c), Antonio Marcus de Andrade Paes(a)
a Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão, Avenida dos Portugueses, 1966, 65.080-805 São Luís, MA, Brazil
b Laboratory of Molecular and Cellular Pathology, Department of Pathology, Federal University of Maranhão, Avenida dos Portugueses, 1966, 65.080-805 São Luís, MA, Brazil
c Laboratory of Vascular Biology, Heart Institute, University of São Paulo, Avenida Enéas de Carvalho Aguiar, 44, 05.403-900 São Paulo, SP, Brazil
Biochemical and Biophysical Research Communications | Volume 443, Issue 2, 10 January 2014, Pages 725-730

...Highlights
MSG-obese rats exhibit metabolic and morphologic features of metabolic syndrome.
VLDL synthesis and secretion is twofold in MSG-obese rats.
ER stress sensors and XBP-1/PDI/MTP axis are overexpressed in MSG-obese rats.

Drug-Metabolizing and Antioxidant Enzymes in Monosodium 
L-Glutamate Obese Mice - HERE (full report)

Petra Matoušková, Hana Bártíková, Iva Boušová, Lucie Levorová, Barbora Szotáková and Lenka Skálová
Drug Metabolism and Disposition February 2015, 43 (2) 258-265

Abstract
...In contrast, elevated activities of NQO1 and UGT1A may cause alterations in drug pharmacokinetics in obese individuals. Moreover, decreased capacity of GST in obese animals indicates potentially reduced antioxidant defense and weaker chemoprotection.

Altered behavior of adult obese rats by monosodium l-glutamate neonatal treatment is related to hypercorticosteronemia and activation of hypothalamic ERK1 and ERK2. HERE

Guimarães ED(1), de Caires Júnior LC(1), Musso CM(1), Macedo de Almeida M(1), Gonçalves CF(2), Pettersen KG(2), Paes ST(2), González Garcia RM(1), de Freitas Mathias PC(3), Torrezan R(3), Mourao-Júnior CA(2), Andreazzi AE(2).
1 a Laboratory of Cellular and Molecular Biology, Department of Biology , Federal University of Juiz de Fora , Juiz de Fora, Brazil.
2 b Laboratory of Physiology, Department of Physiology , Federal University of Juiz de Fora , Juiz de Fora , Brazil.
3 c Department of Cell Biology , State University of Maringá , Maringá , Brazil.
Nutr Neurosci. 2017 Apr;20(3):153-160.

Abstract
...RESULTS:
Increased Lee index and fat pads were observed in Ob-MSG and Ob-Diet groups. Ob-MSG presented a higher level of anxiety and impaired long-term memory compared to C-MSG, while there was no difference between Ob-Diet and C-Diet. The Ob-MSG group presented a higher level of plasmatic corticosterone and increased phosphorylation of hypothalamic ERK1 and 2.

DISCUSSION:
Both treatments induced obesity but only Ob-MSG showed altered behavioral parameters, which is related to increased concentration of corticosterone and hypothalamic ERK1 and 2 activation.

High dosage of monosodium glutamate causes deficits of the 
motor coordination and the number of cerebellar Purkinje cells of rats. HERE

Prastiwi D(1), Djunaidi A(2), Partadiredja G(3).
1 Department of Physiology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia Nursing Program, Faculty of Health Sciences, Pekalongan University, Central Java, Indonesia.
2 Department of Physiology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
3 Department of Physiology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
Hum Exp Toxicol. 2015 Nov;34(11):1171-9.

Abstract
...The motor coordination of the rats was examined prior and subsequent to the treatment. The number of cerebellar Purkinje cells was estimated using physical fractionator method. It has been found that the administration of MSG at a dosage of 3.5 mg/g bw, but not at lower dosages, caused a significant decrease of motor coordination and the estimated total number of Purkinje cells of rats. There was also a significant correlation between motor coordination and the total number of Purkinje cells.

Histological and Immunohistochemical Study of the Effect of Monosodium l-Glutamate on the Jejunal Mucosa of Adult Albino Rat and the Possible Role of Propolis - HERE

Amany Mousa, Tanta University
Article in Egyptian Journal of Histology 36(3) · September 2013

Propolis is a bee product that has a broad spectrum of biological activities including antioxidative, antimicrobial, and anti-inflammatory effects. Aim of the work This work aimed to study the effect of MSG on the jejunal mucosa of adult albino rat and to evaluate the possible role of propolis as a protective agent.... Conclusion MSG induced structural changes in rat jejunal mucosa that could be ameliorated by concomitant treatment with propolis.

A histological study on the effect of prenatal and postnatal administration of monosodium glutamate on the developing renal cortex of male albino rats - HERE

Hoda A.M. Abdel-Aziz, Heba K.Mohamed
Article in Egyptian Journal of Histology 36(2):470-482 · June 2013

...Results
Maternal MSG administration affected both the renal glomeruli and tubules of the offspring. In the newborn stage, the glomeruli at the subcapsular zone appeared immature and crowded. The foot processes showed apparent elongation and disruption of their interdigitations. In weaned rats, apparent widening of Bowman’s space in some glomeruli, detachment of podocytes and effacement of foot processes were noticed. In adult rats, the glomeruli showed hypercellularity with apparent elongation and fusion of the foot processes. The renal tubules at the different ages studied showed degenerative changes with sloughs inside the lumen of some tubules accompanied by proliferative changes. The proximal tubules showed partial loss of the brush border. Conclusion MSG causes a delay in the development of glomeruli. Some glomeruli showed hypercellularity with affection of podocytes, which makes the glomeruli liable to glomerulosclerosis.

The induction of obesity in rodents by means of monosodium glutamate. HERE

Bunyan J, Murrell EA, Shah PP.
Br J Nutr. 1976 Jan;35(1):25-39.

Abstract
1. Monosodium glutamate (MSG) was administered by various methods to mice and rats of various ages and the incidence of obesity was later measured. 2. Newborn mice were injected subcutaneously with 3 mg MSG/g body-weight at 1, 2, 3, 6, 7, and 8 d of age; 16% died before weaning. Of the survivors, 90% or more became markedly obese. Mean carcass lipid content was increased by about 120% in both sexes at 20-30 weeks old. In male mice, MSG treatment increased body-weight and epididymal fat pad weight, and greatly decreased adrenaline-stimulated lipolysis in isolated fat cells. Body-eright of females was not increased significantly. Food intake was not increased in either sex from weeks 13 to 15. Blood glucose level was not generally increased by MSG but some of the male mice had abnormally high values. 3. Obesity was not detected in the offspring of female mice that had received 100 g MSG/kg diet, either from 3 weeks before mating until weaning, or from the 14th day of pregnancy until weaning. 4. Intraperitoneal injection of 10 mg MSG/g body-weight (in two doses) at weaning increased carcass lipid content in female mice by 34% by 23 weeks of age, but female rats were not affected. 5. The addition of 20 g MSG/l to the drinking-water from weaning onwards did not increase carcass lipid content in female rats or mice. 6. The addition of 20 g MSG/kg diet from weaning onwards did not alter body-weight or carcass lipid content in male and female rats by 14 weeks of age. 7. The obesity induced in mice by MSG was not associated with hyperphagia, unlike genetic obesity and obesity induced by gold thioglucose (GTG). 8. All types of mouse studied, obese and lean, had essentially the same linear relationship between carcass water content and carcass lipid content. 9. Although MSG-obese mice could not readily be differentiated from normal mice by the increase in body-weight, which was only about 10% compared to 50-120% for genetic and GTG-induced obesity, the proposed schedule of injections in the newborn was almost 100% reliable in inducing a high extent of adiposity.

The Effects of Neonatally-Administered Monosodium Glutamate 
on the Reproductive System of Adult Hamsters - HERE (pdf)

Albert Lamperti, Gordon Blaha
Biology of Reproduction, Volume 14, Issue 3, 1 April 1976, Pages 362–369.

Abstract
Saline or 4 or 8 mg MSG/gm was administered to hamsters on Days 1-5, 6-10, and 1-10 neonatally. When sacrificed on Day 60, MSG-treated animals had reproductive organ weights significantly lower than control values. Lesions in the arcuate nucleus were detectable only in hamsters which received 8 mg MSG/gm on Days 6-10 or 1-10. Female hamsters were acyclic and had ovaries with small follicles and with no corpora lutea. Administration of 50 IU PMS to these animals caused follicular maturation; ovulation occurred only after administration of 10 IU HCG. Male hamsters had atrophic seminiferous tubules and minimal activity of Δ5-3β-steroid dehydrogenase in the interstitial cells. The histology of the seminiferous tubules and the activity of Δ5-3β-steroid dehydrogenase approached control levels when 200 IU HCG/day was administered for 7 days. The evidence suggests that MSG affects the hypothalamic center controlling pituitary FSH and LH release when administered on Days 6-10 or 1-10 of the neonatal period.

Late endocrine effects of administering monosodium glutamate to neonatal rats. HERE

Bakke JL, Lawrence N, Bennett J, Robinson S, Bowers CY.
Neuroendocrinology. 1978;26(4):220-8.

Abstract
Rats were injected with monosodium 1-glutamate (MSG) daily for the 1st 5 days of life and allowed to mature. This is known to cause selective destruction of neurons in the retina and in the arcuate nucleus of the hypothalamus. The adult animals had a significant increase in body fat without an increase in weight, a marked reduction in pituitary, thyroid, adrenal, gonadal and prostate weights. Pituitary, hypothalamic and serum thyrotropin (TSH) were significantly reduced in the males. Serum growth hormone (GH) was markedly reduced in both sexes and the serum prolactin (Prl) was increased significantly in females. FSH did not appear to be abnormal and the LH may have been increased in the males. Serum T4 was significantly reduced in females. The fertility of the females was normal, but treated males mated with normal females showed a marked reduction in fertility and, although the litter sizes of the offspring were normal, the birth weights of the pups of both sexes were significantly reduced. These persistent alterations in neuroendocrine function indicate that lesions produced by neonatal MSG treatment provide a convenient model for studying hypothalamic function.

Monosodium glutamate administration to the newborn reduces
 reproductive ability in female and male mice. HERE

Pizzi WJ, Barnhart JE, Fanslow DJ.
Science. 1977 Apr 22;196(4288):452-4.

Monosodium glutamate (MSG) administered during the neonatal period (days 2 to 11) resulted in a sequence of events that were manifested in adulthood. Reproductive dysfunction was seen in both female and male animals. Females treated with MSG had fewer pregnancies and smaller litters, while males treated with MSG showed reduced fertility. The MSG-treated mice showed increased body weight and decreased pituitary, thyroid, ovary, or testis weights.

Effects of Monosodium Glutamate on Pro-opiomelanocortin Gene Expression 
in Rat Pituitary Gland and AtT-20 Tumor Cells - HERE (pdf available)

Khomsorn Lomthaisong, Anuwat Wanthong
Chiang Mai University Journal of Natural Sciences 14(1) · January 2015 

Abstract...This result has demonstrated that MSG has different effects on POMC gene expression between pituitary gland and pituitary tumor cells. This suggests that MSG has a neuronal excitatory effect on pituitary functions that enhances POMC gene expression by increasing the stress input through the central nervous system in response to high doses of MSG treatment. In contrast, in vitro, MSG decreased POMC gene expression in pituitary tumor cells; this may be a result of an excitatory toxic effect of MSG on those cells.

Analysis of the Disruption in Hypothalamic-Pituitary Regulation in Rats Treated Neonatally with Monosodium L-Glutamate (MSG): Evidence for the Involvement of Tuberoinfundibular Cholinergic and Dopaminergic Systems in Neuroendocrine Regulation - HERE

CHARLES B. NEMEROFF, RICHARD J. KONKOL, GARTH BISSETTE, WILLIAM YOUNGBLOOD, JOSEPH B. MARTIN, PAUL BRAZEAU, MICHAEL S. RONE, ARTHUR J. PRANGE, JR., GEORGE R. BREESE, JOHN S. KIZER
Endocrinology, Volume 101, Issue 2, 1 August 1977, Pages 613–622.

...From these findings several conclusions were drawn: 1) The MSG-induced endocrine deficiency syndrome appears to result from the destruction of ARC-ME dopaminergic and cholinergic tuberoinfundibular systems within the hypothalamus; 2) a normal concentration of serotonergic and noradrenergic neurons within the hypothalamus does not insure normal central neuroendocrine regulation; 3) no more than 50% of the dopaminergic terminals in the ME arise from ARC perikarya; 4) cell bodies within the ARC contribute very few, if any, nerve terminals containing releasing factors to the ME; 5) MSG destroys the primary optic tracts while sparing the retino-hypothalamic projection; 6) LHRH, somatostatin and TRH are not contained within cholinergic nerve terminals in the ME.

alpha-Melanocyte-stimulating hormone: reduction in adult rat brain 
after monosodium glutamate treatment of neonates. HERE

Eskay RL, Brownstein MJ, Long RT.
Science. 1979 Aug 24;205(4408):827-9.

Abstract
Intraperitoneal injection of monosodium glutamate in neonatal rates resulted in a 90 percent loss of alpha-melanocyte-stimulating hormone in hypothalamic and extrahypothalamic areas of the brain, whereas the amount of hormone in the pituitary gland did not change. The dramatic reduction of alpha-melanocyte-stimulating hormone in the brain suggests that is primary source there is the neuronal perikarya of the arcuate nucleus.

Changes in hippocampal synaptic functions and protein expression in monosodium glutamate-treated obese mice during development of glucose intolerance - HERE

Sachie Sasaki-Hamada, Yuki Hojo, Hajime Koyama, Hayuma Otsuka
Article in European Journal of Neuroscience 41(11) · April 2015

...These results suggest that deficits in glutamatergic presynapses as well as postsynapses lead to impaired synaptic plasticity in MSG-treated mice during the development of glucose intolerance, though it remains unknown whether impaired LTP is due to altered inhibitory transmission. It may be important to examine changes in glucose tolerance in order to prevent cognitive malfunctions associated with diabetes.

Effect of dietary monosodium glutamate on trans fat-induced 
nonalcoholic fatty liver disease - HERE (full report)

Kate S. Collison,1 Zakia Maqbool, Soad M. Saleh, Angela Inglis, Nadine J. Makhoul, Razan Bakheet, Mohammed Al-Johi, Rana Al-Rabiah, Marya Z. Zaidi, and Futwan A. Al-Mohanna
Journal of Lipid Research 2009 August; 50(8): 1521-1537

...In conclusion, we have established an animal model of diet-induced NAFLD that has allowed us to speculate on the contribution of abdominal WAT to the pathogenesis of hepatic steatosis. Dietary MSG at doses similar to the average daily intake caused hepatic microsteatosis and the expression of β-oxidative genes in the offspring of mice previously established on the diet. Fasting serum TG, FFA, and insulin levels were elevated. WAT adipocytes were enlarged and showed an increase in lipid biosynthetic gene expression and a decrease in Ppargc1a levels. Trans-fat feeding increased serum leptin, HDL-C, and T-CHOL levels, while robustly elevating hepatic lipogenesis and lipid catabolism. A combination of TFA+MSG resulted in the highest levels of serum leptin, HDL-C, and T-CHOL, while reducing hepatic lipogenic gene expression and increasing markers of inflammation, lipid storage, DNA damage, and cell cycle impairment. In the adipocytes, Ppargc1a and REDOX gene expression were reduced compared with TFA alone, and several lipogenic genes were upregulated. Therefore, MSG augments trans-fat induced hepatic steatosis by altering WAT gene expression and elevating serum lipids and markers of hepatic fibrosis, inflammation, and DNA damage. Whether the MSG/TFA interaction is mirrored by other dietary fatty acids remains to be elucidated. Further investigation into the molecular pathology of diet-induced NAFLD should address the interaction between other dietary lipids and MSG.

Monosodium Glutamate-Sensitive Hypothalamic Neurons 
Contribute to the Control of Bone Mass - HERE (pdf available)

Florent Elefteriou, Shu Takeda, Xiuyun Liu, Dawna Armstrong
Endocrinology 144(9):3842-7 · October 2003

...This study reveals that distinct populations of hypothalamic neurons are involved in the control of bone mass and demonstrates that MSG-sensitive neurons control bone formation in a leptin-independent manner. It also indicates that NPY deficiency does not affect bone mass.

Monosodium glutamate neonatal treatment induces cardiovascular 
autonomic function changes in rodents - HERE (pdf available)

Signorá Peres Konrad, Vera de Moura Azevedo Farah, Bruno Rodrigue, Ubiratan F Machado, Heno Lopes, Rogerio Brandão Wichi, Beatriz D Schaan, Kátia De Angelis & Maria Claudia Irigoyen
October 2012 Clinics (São Paulo, Brazil) 67(10):1209-14

..Our results suggest that obesity induced by neonatal monosodium glutamate treatment impairs cardiac autonomic function and most likely contributes to increased arterial pressure and insulin resistance.

Secretion of luteinizing hormone in ovariectomized adult 
rats treated neonatally with monosodium glutamate. HERE

Dyer RG, Weick RF, Mansfield S, Corbet H.
J Endocrinol. 1981 Nov;91(2):341-6.

...Thus, although some aspects of LH secretion seem to be significantly different in MSG-treated rats, these effects may result from the greater sensitivity of the MSG-treated animals to experimental manipulation.

Models of neuroendocrine regulation: use of 
monosodium glutamate as an investigational tool. HERE

Nemeroff CB, Lipton MA, Kizer JS.
Dev Neurosci. 1978;1(2):102-9.

...These data indicate that the MSG-induced endocrine deficiency syndrome results at least partly from destruction of cholinergic and dopamingeric tuberoinfundibular systems in the hypothalamus.

Alterations in immunoreactive somatostatin levels in hypothalamic and gastroenteropancreatic tissue as a consequence of neonatal treatment with monosodium glutamate. HERE

DePaolo LV, Steger RW.
Proc Soc Exp Biol Med. 1985 Mar;178(3):419-25.

..These results show that neonatal MSG treatment not only affects IRS levels in the hypothalamus and blood as previously reported, but in parts of the GEP system as well. Further, effects on hypothalamic IRS levels are opposite to those on GEP IRS levels. The significance of these findings may relate to the altered metabolic state of these animals as a consequence of perturbations in the secretion of other hormones from the hypothalamus, anterior pituitary gland, and possibly the GEP system.The results obtained suggest that the rat hypothalamic centres involved in regulation of the pituitary-thyroid axis are slightly affected by neonatal MSG treatment.

Monosodium l-glutamate and dietary fat exert opposite effects on the 
proximal and distal intestinal health in growing pigs - HERE (pdf available)

Zemeng Feng(a), Tiejun Li(a), Chunli Wu(b), Lihua Tao(a), Francois Blachier(c), Yulong Yina

a Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Research Center of Healthy Breeding Livestock and Poultry, Hunan Engineering and Research Center of Animal and Poultry Science, Key Lab Agro-ecology Processing Subtropical Region, Scientific Observational and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, Peoples Republic of China.
b College of Chemistry and Chemical Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, Peoples Republic of China.
c Nutrition Physiology and Ingestive Behavior, UMR914 INRA/AgroParisTech, Paris, France.
Applied Physiology, Nutrition, and Metabolism, 2015, 40(4): 353-363.

Abstract...Overall, dietary fat and MSG had detrimental effects on several of the physiological and inflammatory parameters measured in the proximal intestine, while exerting beneficial effects on the distal intestine in growing pigs, with generally antagonistic effects. These results may be of particular relevance for nutritional concerns in patients with intestinal diseases.

Biochemical alterations during the obese-aging process in female 
and male monosodium glutamate (MSG)-treated mice. HERE

Hernández-Bautista RJ(1), Alarcón-Aguilar FJ(2), Del C Escobar-Villanueva M(3), Almanza-Pérez JC()4, Merino-Aguilar H(5), Fainstein MK(6), López-Diazguerrero NE(7).

1 Post-Grade in Experimental Biology, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
2 Laboratory of Pharmacology, Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
3 Laboratory of Pharmacology, Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
4 Laboratory of Pharmacology, Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
5 Laboratory of Pharmacology, Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
6 Laboratory of Bioenergetics and Cellular Aging, Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
7 Laboratory of Bioenergetics and Cellular Aging, Department of Health Sciences, Division of Health and Biological Sciences, Metropolitan Autonomous University, A.P. 55-535, D.F. Mexico, Mexico.
Int J Mol Sci. 2014 Jun 27;15(7):11473-94.

...In summary, MSG-treated obese mice showed metabolic changes and differential susceptibility by gender throughout life and during the aging process. Understanding metabolic differences between genders during the lifespan will allow the discovery of specific preventive treatment strategies for chronic diseases and functional decline.

Evidence that reduced growth hormone secretion observed in monosodium glutamate-treated rats is the result of a deficiency in growth hormone-releasing factor. HERE

Millard WJ, Martin JB Jr, Audet J, Sagar SM, Martin JB.
Endocrinology. 1982 Feb;110(2):540-50.

Abstract...In view of the mechanisms by which MS and pentobarbital act to increase GH secretion, the present data suggest that the GH regulatory deficit observed in MSG-treated rats is due to a relative loss of GH-releasing factor secondary to ARC damage.

Neonatal monosodium glutamate treatment alters both the activity and the
 sensitivity of the rat hypothalamo-pituitary-adrenocortical axis - HERE

Authors: P J Larsen, J D Mikkelsen, D Jessop, S L Lightman and H S Chowdrey
Journal of Endocrinology (1994) 141, 497–503

...The evidence is consistent with the suggestion that MSG lesions a pathway involved in tonic inhibition of the HPA axis. In addition, the adrenocortical sensitivity to ACTH and other secretagogues may be increased in MSG-treated animals.

The neonatal neurotoxicity of monosodium L-glutamate on the 
sexually dimorphic nucleus of the preoptic area in rats. HERE

Hsieh YL(1), Hsu C, Lue SI, Hsu HK, Peng MT
1. Department of Physiology, Kaohsiung Medical College, Taiwan, ROC.
Developmental Neuroscience, 01 Jan 1997, 19(4):342-347

...The results indicate that neonatal MSG treatment caused significant neuronal loss and decreases in total volume of the SDN-POA and non-SDN-POA of male and female rats. However, only the SDN-POA of MSG-treated male rats showed a significant increase of pyknosis and decrease of neuronal density. A significant enlargement of NNV in the SDN-POA and non-SDN-POA was observed in the MSG-treated male rats. These results indicate that the MPN shows sex-specific and area-specific changes after neonatal neurotoxicity due to MSG.

Effects of neonatal treatment with MSG (Monosodium glutamate) 
on hypothalamopituitary-thyroid axis in adult male rats - HERE (pdf)

B. Miskowiak and M. Partyka
Department of Histology and Embryology, K. Marcinkowski University of Medical Sciences, Poznan, Poland
Histol Histopath (1 993) 8: 731 -734 

...MSG-treated rats showed stunted growth, obesity and decreased pituitary weight. MSG administration resulted in increases in thyroid weight, absolute volumes of epithelium, colloid and stroma, and blood T3 level while T4 level remained unchanged. In enlarged thyroid gland, percentage fractions occupied by epithelium, colloid and stroma were similar to those observed in control rats.
The results obtained suggest that the rat hypothalamic centres involved in regulation of the pituitary-thyroid axis are slightly affected by neonatal MSG treatment.

Monosodium glutamate disruption of behavioral 
and endocrine function in the female rat. HERE

Rodriguez-Sierra JF, Sridaran R, Blake CA.
Neuroendocrinology. 1980 Sep;31(3):228-35.

...Neonatal MSG treatment appears to affect the neural control for the tonic secretion of gonadotropins by destroying arcuate nuclei. This undoubtedly reduces the reproductive capacity of the animals by impeding the growth and secretions of their ovaries. The findings that chronic estrogen followed by progesterone treatment can reinstate sexual receptivity in MSG-treated animals suggests that the arcuate nuclei are not needed for the expression of sexual behavior and that estrogens might remedy the fertility problems of MSG-treated animals.

Homeostatic effect of p-chloro-diphenyl diselenide on glucose metabolism and mitochondrial function alterations induced by monosodium glutamate administration to rats. HERE

Quines CB(1), Rosa SG(1), Chagas PM(1), da Rocha JT(1), Dobrachinski F(2), Carvalho NR(2), Soares FA(2), da Luz SC(3), Nogueira CW(4,5).

1 Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, CEP 97105-900, Brazil.
2 Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus UFSM, Santa Maria, RS, 97105-900, Brazil.
3 Departamento de Patologia, Universidade Federal de Santa Maria, Santa Maria, RS, CEP 97105-900, Brazil.
4 Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, CEP 97105-900, Brazil. criswn@ufsm.br.
5 Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus UFSM, Santa Maria, RS, 97105-900, Brazil.
Amino Acids. 2016 Jan;48(1):137-48. doi: 10.1007/s00726-015-2073-3.

...In summary, (p-ClPhSe)2 had homeostatic effects on glucose metabolism and mitochondrial function alterations induced by MSG administration to rats.

Subcutaneous administration of monosodium glutamate to pregnant 
mice reduces weight gain in pups during lactation. HERE

Park JH(1), Choi TS(2).
1 Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Chonan, Republic of Korea Department of Microbiology, College of Medicine, Dankook University, Chonan, Republic of Korea.
2 Department of Microbiology, College of Medicine, Dankook University, Chonan, Republic of Korea
Lab Anim. 2016 Apr;50(2):94-9.

...Although there were no differences in prolactin levels, morphological analyses of the mammary glands revealed apparent differences, including low numbers and altered phenotype of alveoli, between the control and MSG-treated groups. Taken together, our results show that treating pregnant mice with excess MSG induced lower neonate body weight gain during lactation.

Lycopene modulate cholinergic dysfunction, Bcl2/Bax balance and antioxidant enzymes gene transcripts in monosodium glutamate (E621) - induced neurotoxicity in a rat model - HERE (pdf available)

Kadry Sadek, Tarek Abouzed, and Sherif Nasr
Canadian Journal of Physiology and Pharmacology 94(4) · November 2015 

...Our results indicate that lycopene appears to be highly effective in relieving the toxic effects of MSG by inhibiting lipid peroxidation and inducing modifications in the activity of cholinesterase and antioxidant pathways. Interestingly, lycopene protects brain tissue by inhibiting apoptosis signaling induced by MSG.

Immunohistochemical evaluation of hippocampal CA1 region astrocytes 
in 10-day-old rats after monosodium glutamate treatment. HERE

Krawczyk A, Jaworska-Adamu J, Rycerz K.
Pol J Vet Sci. 2015;18(4):767-74.

...These results suggest the increased expression of the proteins in early reactions or hyperplasia which, together with cell hypertrophy, indicate late reactivity of astroglia in response to glutamate noxious effect.

Alterations in insulin and glucagon secretion by monosodium 
glutamate lesions of the hypothalamic arcuate nucleus. HERE

Sartin JL, Lamperti AA, Kemppainen RJ.
Endocrine Research. 1985;11(3-4):145-55.

...The MSG group had significantly more glucagon (P less than 0.05) in portal vein blood at 30 min after glucose administration than did the control hamsters. Molar insulin/glucagon ratios did not differ between the 2 groups which likely accounts for the lack of differences in blood glucose levels. These results suggest a role for the ARC in regulating pancreatic function.

The Damaging Effect of Systemic Injection of Monosodium Glutamate (MSG) on the Development of Normal and Form-Deprived Eyes of the Chick - HERE (pdf)

Chi Kong Yeung, Ph.D.,* Sylvia W. Y. Chiang, B.Pharm.,
Chi Pui Pang, D.Phil., and Dennis S. C. Lam, F.R.C.S., FRCOphth
Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong, P.R. China
Journal of Toxicology | CUTANEOUS AND OCULAR TOXICOLOGY | Vol. 23, No. 1, pp. 1–12, 2004

...The results show that MSG significantly reduced the eye weight (EW), ocular length (OL), and equatorial diameter (ED) of the normal (i.e. with MSG treatment but not form-deprived) ocular
growth... As a result of FDM, these measurements of the eye tend to increase as well as result in thinning of the retina and thickening of the sclera.

The Damaging Effect of Systemic Injection of Monosodium Glutamate (MSG) on the Development of Normal and Form-Deprived Eyes of the Chick - HERE (full report)

Chi Kong Yeung, Ph.D.,* Sylvia W. Y. Chiang, B.Pharm.,
Chi Pui Pang, D.Phil., and Dennis S. C. Lam, F.R.C.S., FRCOphth
Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong, P.R. China
Journal of Toxicology | CUTANEOUS AND OCULAR TOXICOLOGY Vol. 23, No. 1, pp. 1–12, 2004

...The results show that MSG significantly reduced the eye weight (EW), ocular length (OL), and equatorial diameter (ED) of the normal (i.e. with MSG treatment but not form-deprived) ocular
growth... As a result of FDM, these measurements of the eye tend to increase as well as result in thinning of the retina and thickening of the sclera.

Visual performance in monosodium glutamate-treated rats. HERE

Praputpittaya C(1), Wililak A.
1 Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand.
Nutr Neurosci. 2003 Oct;6(5):301-7.

 ...In conclusion, glutamate treatment was shown to cause dose-dependent deficit in visual performance and this may reflect impairment of visual organs and brain function.

EFFECT OF MONOSODIUM GLUTAMATE ON THE ENDOCRINE GLANDS
AND ON THE REPRODUCTIVE FUNCTION OF THE RAT - HERE (pdf)

GIAN PAOLO TRENTINI, M.D., L.D., ANNIBALE BOTTICELLI, M.D., L.D., AND CATERINA SANNICOLA BOTTICELLI, D.Sc.
Institute of Pathological Anatomy, University of Modena, 41100 Modena, Italy
FERTILITY AND STERILITY | Vol.25, No. 6, 6th June, 1974 (Copyright © 1974 The American Fertility Society)

..Discussions...MSG is known to be toxic in infant mice and rats, (12,16-18) as was confirmed by the convulsions observed in our experimental animals. Moreover, our observation of precocious vaginal canalization and increased occurrence of estrous in the treated rats supports Olney's data in that MSG has a cytotoxic effect on the arcuate nucleus of the hypothalamus. Lesions damaging part of the arcuate nucleus cause premature sexual development (ie, precocious follicular maturation with
earlier vaginal opening and prolonged estrous(19-22) because of the removal of a hypothalamic, follicle -stimulating hormone (FSH)-inhibiting effect or of the interruption of the gonadal feedback mechanism...

Sex-related alterations in hypothalamic tyrosine hydroxylase 
after neonatal monosodium glutamate treatment. HERE

Arbogast LA1, Voogt JL.
1 Department of Physiology, University of Kansas Medical Center, Kansas City.
Neuroendocrinology. 1990 Nov;52(5):460-7.

...Neonatal MSG-treatment resulted in a marked reduction in the number of TH mRNA-containing cells and TH-immunopositive cells in the arcuate nucleus of both sexes, as well as a decrease in the intensity of TH immunostaining in the median eminence. The cellular mRNA signal levels for TH were markedly reduced in females after MSG treatment, but were unchanged in males. MSG treatment reduced TH activity to 20% of control levels in females, but did not alter enzyme activity in males.

Nature and Extent of Brain Lesions in Mice Related to Ingestion of 
Monosodium Glutamate: A Light and Electron Microscope Study - HERE

N. Lemkey-Johnston, Ph.D., W. A. Reynolds, Ph.D.
Journal of Neuropathology & Experimental Neurology, Volume 33, Issue 1, January 1974, Pages 74–97

...Abstract
The incidence of arcuate neuron damage following 1 to 4 mg/gm oral doses of monosdoium glutamate (MSG) to neonatal mice was studied. The first morphological manifestation of the lesion involved edematous astrocytic glia and pathological changes in neurons close to the median eminence within 15–20 minutes. The sequence of the lesion involved at least three phases: 1) neuronal edema and death, 2) multiple phagocytic cells, viz. a type of “dense” cell and an electron “lucid” cell astrocyte, and 3) proliferation of astrocytic processes. It was noted that at 4 mg doses, the lesions occurred in other areas such as tectum, habenular nuclei, subfornical organ, dorsolateral surface of the thalamus, dentate-hippocampal gyri, cerebral cortex, and in the lower medulla, the nuclei gracilis and cuneatus and area postrema. In all. these structures, the lesion was initiated superficially and radiated inward, suggesting an inflow of the deleterious agent from the cerebrospinal fluid. Comparison of our neuropathological findings with those of others, emphasized the critical aspects of species variation, developmental age, route of administration, time of examination of brain material after dosage and thoroughness of sampling methods.

Benefits of L-alanine or L-arginine supplementation against adiposity and 
glucose intolerance in monosodium glutamate-induced obesity - HERE (pdf available)

Thiago R. Araujo, Israelle N. Freitas, Jean F. Vettorazzi, Thiago M. Batista, Junia C. Santos-Silva, Maria L. Bonfleur, Rosane Aparecida Ribeiro, Everardo M Carneiro
European Journal of Nutrition 56(6) · June 2016

...Conclusions Ala supplementation led to more pronounced metabolic improvements compared to Arg, possibly due to suppression of lipogenesis through activation of the AMPK/ACC pathway.

Effect of monosodium glutamate on lipid peroxidation and certain 
antioxidant enzymes in cardiac tissue of alcoholic adult male mice - HERE

Kuldip Singh and Pushpa Ahluwalia(1)
Department of Biochemistry, Govt. Medical College – Amritsar, India
1 Department of Biochemistry, Panjab University, Chandigarh, India
J Cardiovasc Dis Res. 2012 Jan-Mar; 3(1): 12–18.

Results:
A significant (P < 0.001) increase was observed in LPO and XOD levels while a significant decrease (P < 0.001) in the levels of SOD, CAT, GSH, GPx and GR was found in cardiac tissue of normal and alcoholic animals.

Conclusion:
These observations suggested that oral ingestion of MSG at dose levels of 4 mg/g body weight and above with and without alcohol increased the oxidative stress and thereby, could act as an additional factor for the initiation of atherosclerosis.

Chronic Administration of Monosodium Glutamate under Chronic Variable Stress Impaired Hypothalamic-Pituitary-Adrenal Axis Function in Rats - HERE (pdf available)

Hee Jeong Seo(1), Hyang-Do Ham(1), Hyung Yong Jin(1), Woo Hyung Lee(1), Hyun Sub Hwang(1), Soon-Ah Park(2), Yong Sung Kim(3), Suck Chei Choi(3), Seoul Lee(3), Kyung Jae Oh(3), Byung Sook Kim(4), Byung Rim Park(1), and Moon Young Lee(1)
1 Department of Physiology and Digestive Disease Research Institute,
2 Department of Nuclear Medicine,
3 Institute of Wonkwang Medical
Science, School of Medicine, Wonkwang University, Iksan 570-749, 4
Department of Food and Nutrition, Jeonbuk Science College, Iksan
580-712, Korea
Korean Journal of Physiology and Pharmacology 14(4):213-21 · August 2010

...The increase in relative adrenal weights in the CVS and CVS+MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS+MSG group as compared to all other groups, except the naïve group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

Study of lysosomal changes in rat pancreas after ingesting monosodium L-glutamate. HERE

Lee KT(1), Sheen PC
1. Department of Surgery, Kaohsiung Medical College Hospital, Taiwan, R.O.C.
Pancreas, 01 May 1994, 9(3):304-308

...The ultrastructural changes in pancreatic acinar cells revealed an increase in the number and size of autophagic vacuoles and various sizes of myelin figures in the cytoplasm and interstitial space. Dilatation of rough endoplasmic reticulum, swollen mitochondria, and altered zymogen granules were occasionally found. These changes occurred most often in Group I rats, which ingested 1% MSG for 1 month. The changes became less prominent as the dose of MSG administered was lessened. A reaction product of ACPase could also be seen in autophagic vacuoles in Group I rats. Regarding quantitative measurement, the serum level of ACPase for Group I rats was markedly higher than that of the controls and was statistically significant (20.52 +/- 4.92 vs. 12.62 +/- 4.13 U/L; p < 0.05)

Neonatal exposure to monosodium glutamate induces morphological
 alterations in suprachiasmatic nucleus of adult rat - HERE

Julio rojas-castaneda, Rosa María Vigueras-Villaseñor, Margarita Chávez-Saldaña, Patricia Rojas, Oscar Gutiérrez Pérez, Carolina Rojas, Marcela Arteaga Silva
International Journal of Experimental Pathology 97(1) · January 2016

Abstract
Neonatal exposure to monosodium glutamate (MSG) induces circadian disorders in several physiological and behavioural processes regulated by the suprachiasmatic nucleus (SCN). The objective of this study was to evaluate the effects of neonatal exposure to MSG on locomotor activity, and on morphology, cellular density and expression of proteins, as evaluated by optical density (OD), of vasopressin (VP)-, vasoactive intestinal polypeptide (VIP)- and glial fibrillary acidic protein (GFAP)-immunoreactive cells in the SCN. Male Wistar rats were used: the MSG group was subcutaneously treated from 3 to 10 days of age with 3.5 mg/g/day. Locomotor activity was evaluated at 90 days of age using 'open-field' test, and the brains were processed for immunohistochemical studies. MSG exposure induced a significant decrease in locomotor activity. VP- and VIP-immunoreactive neuronal densities showed a significant decrease, while the somatic OD showed an increase. Major axes and somatic area were significantly increased in VIP neurons. The cellular and optical densities of GFAP-immunoreactive sections of SCN were significantly increased. These results demonstrated that newborn exposure to MSG induced morphological alterations in SCN cells, an alteration that could be the basis for behavioural disorders observed in the animals.


Monosodium glutamate alters the response properties of rat trigeminovascular 
neurons through activation of peripheral NMDA receptors - HERE

MelissaO’Brien(a), Brian E.Cairns(a,b)
a Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, Canada
b Center for Neuroplasticity and Pain, SMI®, Department of Health Science and Technology, The Faculty of Medicine, Aalborg University, Aalborg E, Denmark
Neuroscience | Volume 334, 15 October 2016, Pages 236-244


...These results suggest that MSG-induced headache is mediated by the activation of peripheral NMDA receptors and subsequent dural vasodilation. Peripheral NMDA receptors are a potential target for the development of new drugs to treat headaches.

Epididymal sperm analysis following time and dose dependent administration 
of monosodium glutamate in preadolescent rats - HERE (pdf)

D. Kianifard
Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran, Islamic Republic of...
Fertility and Sterility | September 2016, Volume 106, Isue 3, Supplement Page e288

...Conclusions
The results of this study showed that, dose dependent continuous long-term administration of monosodium glutamate may affect the normal spermatogenesis in preadolescence period and could be induce some spermatogenic alterations and fertility complications in adolescents.

Plasma Levels of Insulin-like Growth Factor-I Are Reduced at One 
Week of Age in Monosodium L-Glutamate-Treated Mice - HERE

TORU YAMAMOTO, SATOSHI MATSUO, YASUO UESHIMA, FUMIO INOUE, AKIHIKO KINUGASA, TADASHI SAWADA
Endocrine Journal | Volume 40 (1993) Issue 4

...These results suggest that a decreased plasma IGF-I level contributes to the retarded linear growth which develops soon after the administration of MSG, and hyperinsulinemia contributes to the later development of obesity in MSG-treated mice.

Reduced brown adipose tissue thermogenesis and metabolic rate in 
pre-obese mice treated with monosodium-L-glutamate. HERE

Yoshioka K(1), Yoshida T, Kondo M.
1 First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
Endocrinol Jpn. 1991 Feb;38(1):75-9.

...Decreases in IBAT mitochondrial GDP binding and oxygen consumption as well as lowered RMR in MSG-treated mice were found even in the pre-obese stage as well as the obese stage, when compared to those in control mice. These findings suggest that reduced BAT thermogenesis may be one of the contributing factors in the development of obesity.

Morphological and cell proliferative study on the growth of visceral 
organs in monosodium L-glutamate-treated obese mice. HERE

Hamaoka K, Kusunoki T.
J Nutr Sci Vitaminol (Tokyo). 1986 Aug;32(4):395-411.

...According to patterns of weight gain compared with those in the control mice, the visceral organs in the MSG-treated mice were classified into three groups as follows: The first group of organs (heart, lungs, spleen, pancreas, kidneys, testes, brain and submandibular glands) remained absolutely lower in weight throughout their growth. The second group of organs (liver and stomach) was low in weight until 12 weeks of age, but became identical to that of the control mice after 16 weeks of age. The third group of organs (epididymal fat, small intestine and colon) showed lower weight until 4 weeks of age and were significantly heavier than those in the control mice after 8 weeks of age. The heart in the first group of organs apparently had hypertrophic muscle cells after 8 weeks of age and became significantly hypoplastic due to decreased cell production as was revealed by the continuous suppression of mitotic activity and DNA synthesis by [3H]thymidine autoradiography. The liver in the second group of organs became significantly hypoplastic due to decreased cell production and showed the same weight with the control mice due to the development of fatty liver. The small intestine in the third group of organs became hypoplastic due to decreased cell production in the crypts until 4 weeks of age, and became hypertrophic and hyperplastic by the acceleration of cell production in the crypts from 4 to 8 weeks of age. From these findings, in the MSG-treated mice with specific growth patterns of visceral organs, it is suggested that low energy expenditure results in a relatively excessive energy supply and leads to obesity, because most of the important organs with major physiological functions became hypoplastic. Moreover, it seems that hypertrophy and hyperplasia of the intestine suggest a possible acceleration of the absorptive function.

Development of the epididymal adipose tissue in 
monosodium glutamate-induced obese mice. HERE

Ochi M1, Fukuhara K, Sawada T, Hattori T, Kusunoki T.
1 Department of Pediatrics, Kyoto Prefectural University of Medicine, Japan.
J Nutr Sci Vitaminol (Tokyo). 1988 Jun;34(3):317-26.

...These results indicate that the MSG-induced obesity is of the hypertrophic type.

Pathological Changes in Hepatocytes of Mice with Obesity-induced 
Type 2 Diabetes by Monosodium Glutamate - HERE (pdf)

Kazuhiko Nakadate, Kento Motojima, Sumito Kamata, Testuro Yoshida, Masaaki Hikita, Hisanori Wakamatsu
YAKUGAKU ZASSHI 134(7) 829-838 2014

...These results suggest that the obese mice might have delayed energy metabolism, which might have influenced the mechanisms of hepatocytes. These findings provide new insight into the functional changes in chronic obesity-induced type 2 diabetes and it is possible that the pathological feature make a contribution to promise the target of pharmacological therapy.

The endocrine disrupting potential of monosodium glutamate (MSG) on secretion of the 
glucagon-like-peptide-1 (GLP-1) gut hormone and GLP-1 receptor interaction - HERE (pdf)

Shannon, M., Green, B., Willars, G., Wilson, J., Matthews, N., Lamb, J., ... Connolly, L. (2017). 
Queens University Belfast | Toxicology Letters, 265, 97-105.

...39 In conclusion, 72 h exposure of an enteroendocrine cell line at dietary levels of MSG, results in pre-lethal cytotoxicity and decline in GLP-1 secretion. These adverse events may play a role in the
pathogenesis of obesity as outlined in the obesogen hypothesis by impairing GLP-1 secretion,
related satiety responses and glucose-stimulated insulin release.

Effects of neonatal administration of monosodium glutamate and castration on 
neurokinin A levels in the hypothalamus and anterior pituitary of rats - HERE

María A.Villanúa, Luciano Debeljuk, Pradip K.Ghosh, Andrzej Bartke
Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL 62901-6512 USA
Peptides | Volume 13, Issue 2, March–April 1992, Pages 377-381

...It is concluded that neonatal MSG treatment resulted in a decrease of hypothalamic NKA, which was particularly pronounced in male rats without any significant change in anterior pituitary NKA levels. The response of hypothalamic NKA to castration and the response of anterior pituitary NKA to ovariectomy were also altered in MSG-treated rats; this may reflect a functional block of some neuroendocrine functions of the hypothalamus that resulted from the neuronal lesions induced by MSG.

Effects of monosodium-L-glutamate administration on serum levels of reproductive hormones and cholesterol, epididymal sperm reserves and testicular histomorphology of male albino rats - HERE (PDF Available)

Izuchukwu S. OCHIOGU(1), David OGW(1,4), Chukwuka N. UCHENDU(2), Chidozie N. OKOYE(1), John I. IHEDIOHA(3) and Edmund C. MBEGBU(2)
1 Department of Veterinary Obstetrics and Reproductive Diseases
2 Department of Veterinary Physiology and Pharmacology and
3 Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka, Enugu State, Nigeria
4 Current address: Department of Veterinary Surgery and Medicine, Ahmadu Bello University, Zaria,
Kaduna State, Nigeria
Acta Veterinaria Hungarica 63(1):125-39 · March 2015

...It was concluded that MSG administration for 14, 28 and 42 days led to significantly lower serum levels of GnRH, LH, testosterone and TC, and significantly lower CESR.

Increase in pituitary dopaminergic receptors after monosodium glutamate treatment. HERE

Heiman ML, Ben-Jonathan N.
Am J Physiol. 1983 Sep;245(3):E261-5.

...The DA binding capacity was significantly higher in MSG-treated rats than in controls with no change in affinity. The data indicate that anterior pituitary DA receptors change in accordance with altered physiological conditions. The increase in the number of DA receptors following destruction of the arcuate nucleus is probably a direct effect of reduced DA levels reaching the anterior pituitary gland.

Auditory hindbrain atrophy and anomalous calcium binding protein 
expression after neonatal exposure to monosodium glutamate. HERE

Foran L(1), Blackburn K(1), Kulesza RJ(2).
1 Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, United States.
2 Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, United States.
Neuroscience. 2017 Mar 6;344:406-417.

Previous studies have shown that MSG administration during the early postnatal period results in neurodegenerative changes in several forebrain regions, characterized by neuronal loss and neuroendocrine abnormalities. Systemic delivery of MSG during the neonatal period and induction of glutamate neurotoxicity in the cochlea have both been shown to result in fewer neurons in the spiral ganglion. We hypothesized that an MSG-induced loss of neurons in the spiral ganglion would have a significant impact on the number of neurons in the cochlear nuclei and superior olivary complex (SOC). Indeed, we found that exposure to MSG from postnatal days 4 through 10 resulted in significantly fewer neurons in the cochlear nuclei and SOC and significant dysmorphology in surviving neurons. Moreover, we found that neonatal MSG exposure resulted in a significant decrease in the expression of both calretinin and calbindin. These results suggest that neonatal exposure to MSG interferes with early development of the auditory brainstem and impacts expression of calcium binding proteins, both of which may lead to diminished auditory function.

Monosodium glutamate versus diet induced obesity 
in pregnant rats and their offspring - HERE

By M.M. Afifi and A.M. Abbas
R1 Medicine (General) / orvostudomány általában. Published by: Akadémiai Kiadó. 10.1556/APhysiol.98.2011.2.9

...Moreover, maternal obesity in pregnancy, caused by MSG, has greater impact on offspring metabolism and BW than that induced by HCC.

(p‐ClPhSe)2 Reduces Hepatotoxicity Induced by Monosodium 
Glutamate by Improving Mitochondrial Function in Rats - HERE

Caroline B. Quines,  Pietro M. Chagas,  Diane Hartmann,  Nélson R. Carvalho,  Félix A. Soares, Cristina W. Nogueira
J. Cell. Biochem. 118: 2877–2886, 2017.

...The present study, demonstrated that postnatal administration of MSG to male rats induced a mitochondrial dysfunction, accompanied by oxidative stress and an increase in the ADP levels, without altering the efficiency of phosphorylation in the liver of adult rats. Furthermore, the MSG administration also induces hepatotoxicity, through an increase in PARP, iNOS, and p38 levels. (p‐ClPhSe)2 treatment had beneficial effects against mitochondrial dysfunction, oxidative stress, and modulated protein markers of apoptosis and inflammation in the liver of MSG‐treated rats.

Marked reduction in gonadal steroid hormone levels in rats treated neonatally 
with monosodium L-glutamate: further evidence for disruption of 
hypothalamic-pituitary-gonadal axis regulation. HERE

Nemeroff CB, Lamartiniere CA, Mason GA, Squibb RE, Hong JS, Bondy SC.
Neuroendocrinology. 1981 Nov;33(5):265-7.

...This marked reduction in gonadal steroid levels (decreases 68%) and inappropriately low gonadotropin levels further characterizes the deficit of feedback regulation in the hypothalamic-pituitary-gonadal axis in MSG-treated rats.

Monosodium glutamate-associated alterations in open field, anxiety-related 
and conditioned place preference behaviours in mice. HERE

Onaolapo OJ(1), Aremu OS(1), Onaolapo AY(2).
1 Department of Pharmacology, Ladoke Akintola University of Technology, Osogbo, Osun State, Nigeria.
2 Department of Anatomy, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
Naunyn Schmiedebergs Arch Pharmacol. 2017 Jul;390(7):677-689. 

...Results showed that administration of MSG was associated with a decrease in rearing, dose-related mixed horizontal locomotor, grooming and anxiety-related response and an increase in brain glutamate/glutamine levels. Following exposure to the CPP paradigm, MSG-naïve and MSG-pretreated mice both showed 'drug-paired' chamber preference. The study concluded that MSG (at the administered doses) was associated with changes in open field activities, anxiety-related behaviours and brain glutamate/glutamine levels; its ingestion also probably leads to a stimulation of the brain reward system.

High-affinity uptake of hypothalamic neurotransmitters in 
mice treated neonatally with monosodium glutamate. HERE

Dawson R Jr, Valdes JJ, Annau Z.
Neuroendocrinology. 1982 Apr;34(4):292-6.

...The results indicate that MSG treatment produced an overall reduction in net hypothalamic uptake, with surviving neuronal elements exhibiting an increased uptake which may reflect compensatory changes in these nerve terminals. MSG may this disrupt pituitary and intrahypothalamic functions via its effects on neuronal systems of the AN.

Resistance exercise reduces memory impairment induced by 
monosodium glutamate in male and female rats. HERE

Araujo PCO(1), Quines CB(1), Jardim NS(1), Leite MR(1), Nogueira CW(1).
1 Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brasil.
Exp Physiol. 2017 Jul 1;102(7):845-853. 

...Resistance exercise was effective against the decrease in recognition for male rats and in location memory for female rats treated with MSG. This report demonstrates the beneficial effects of resistance exercise against the prejudice of motor condition and impairment of memory induced by MSG in male and female rats.

Monosodium glutamate and treadmill exercise: Anxiety-like 
behavior and spreading depression features in young adult rats. HERE

Vitor-de-Lima SM(1), Medeiros LB(1), Benevides RDL(1), Dos Santos CN(1), Lima da Silva NO(1), Guedes RCA(1).
1a Department of Nutrition , Universidade Federal de Pernambuco , Recife , PE 50670901 , Brazil.
Nutr Neurosci. 2019 Jun;22(6):435-443. 

...CONCLUSIONS:
The exercise-dependent attenuation of the effects of MSG confirms our previous results in rats treated subcutaneously with MSG. CSD results suggest two distinct mechanisms for gavage and topical MSG administration. Additionally, data suggest that exercise can help protect the developing and adult brain against the deleterious actions of MSG.

Adverse effects in kidney function, antioxidant systems and histopathology 
in rats receiving monosodium glutamate diet - HERE

María del Carmen Contini, Ana Fabro, Néstor Millen, Adriana Benmelej, Stella Mahieu(1)
Laboratorio de Investigaciones Nutricionales, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, CC 242, 3000 Santa Fe, Argentina
Experimental and Toxicologic Pathology | Volume 69, Issue 7, 5 September 2017, Pages 547-556

...These results indicate that the addition of MSG in the diet decreases the excretion of Na, K and water with hyperfiltration. NaCl retention that leads to hypertension was accompanied by renal pathologic changes, intrarenal oxidative stress and reduction of nitric oxide excretion.

Changes in the expression level of MAPK pathway components 
induced by monosodium glutamate-administration produce neuronal 
death in the hippocampus from neonatal rats. HERE

Rivera-Carvantes MC(1), Jarero-Basulto JJ(2), Feria-Velasco AI(2), Beas-Zárate C(3), Navarro-Meza M(4), González-López MB(2), Gudiño-Cabrera G(3), García-Rodríguez JC(5).

1 Cellular Neurobiology Laboratory, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Zapopan, Jal., Mexico. Electronic address: mrivera939@gmail.com.
2 Cellular Neurobiology Laboratory, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Zapopan, Jal., Mexico.
3 Regeneration and Neural Development Laboratory, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Zapopan, Jal., Mexico.
4 Department of Health and Wellness, CUSur, University of Guadalajara, Ciudad Guzman, Jal., Mexico.
5 National Center of Animal Breeding, Neurotoxicology Area, CENPALAB, Boyeros, Havana, Cuba.
Neuroscience. 2017 Dec 4;365:57-69.

...These results are an evidence of that repetitive use of MSG, in neonatal rats, induces cell damage-associated transcriptional changes of MAPK components, that might reflect a differential stage of both biochemical and molecular brain maturation. This work also suggests that some of the proteins evaluated such as phosphorylated retinoblastoma (pRb) protein, which was up-regulated, could regulate the response to excitotoxic through modulation of the process of re-entry into the cell cycle in the hippocampus of rats treated with MSG.

Monosodium glutamate suppresses the female reproductive function 
by impairing the functions of ovary and uterus in rat. HERE

Mondal M(1), Sarkar K(1), Nath PP(1), Paul G(1).
1 Molecular Neurotoxicology Laboratory, Department of Physiology, University of Kalyani, Kalyani, West Bengal, 741235, India.
Environ Toxicol. 2018 Feb;33(2):198-208.

...This result suggests that MSG potentiates the contraction of uterus probably by stimulating the estradiol sensitivity to oxytocin. From the results it is concluded that MSG suppresses the female reproductive function in rat probably by impairing the functions of ovary and uterus.

Monosodium glutamate impairs the contraction of uterine visceral smooth muscle ex vivo of rat through augmentation of acetylcholine and nitric oxide signaling pathways - HERE

Mukti Mondal, Kaushik Sarkar, Partha Pratim Nath, Ashma Khatun, SanghamitraPal, Goutam Paul
Molecular Neurotoxicology Laboratory, Department of Physiology, University of Kalyani, Kalyani, West Bengal 741235, India
Reproductive Biology | Volume 18, Issue 1, March 2018, Pages 83-93

...These results indicate that MSG potentiates the force of contraction of UVSM predominantly by augmenting the activity of cholinergic intrinsic efferents and inhibits the frequency of contraction probably by augmenting the activity of nitrergic efferents. In conclusion, MSG potentiates the force and inhibits the frequency of contraction of UVSM, and the MSG induced effect is probably mediated through the augmentation of acetylcholine and nitric oxide signaling pathways.

Effects of neonatal monosodium glutamate (MSG) treatment on the hormonal and central monoaminergic dynamics associated with acute ether stress in the male rat - HERE

Craig A.Johnston(1,1), E.J.Spinedi(1,1), A.Negro-Vilar(1,2,1)
1 Department of Physiology, University of Texas Health Science Center, Dallas, TXUSA
2 Reproductive Neuroendocrinology Section, Laboratory of Reproductive and Developmental Toxicology National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
Brain Research Bulletin | Volume 13, Issue 5, November 1984, Pages 643-649

...The results indicate that although MSG treatment causes severe changes in amine metabolism in discrete brain regions, neither the neurochemical nor the hormone response to ether stress appears to be greatly affected. The additional changes in monoamine metabolism observed in MSG rats after ether may represent part of a compensatory mechanism evoked by the central nervous system in adaptation to the neonatally-induced neurochemical deficits.

Impairments in analgesic, hypothermic, and glucoprivic stress 
responses following neonatal monosodium glutamate. HERE

Badillo-Martinez D, Nicotera N, Butler PD, Kirchgessner AL, Bodnar RJ.
Neuroendocrinology. 1984 Jun;38(6):438-46.

...MSG-treated rats displayed significant reductions in both their analgesic and hypothermic responses following CWS, suggesting that MSG treatment impairs an animal's ability to process sufficiently the stimulus properties of the swim as stressful. While MSG treatment potentiated 2-DG analgesia, it reduced 2-DG hyperphagia, suggesting that MSG treatment also impairs coping responses to glucoprivation. These data indicate the importance of the circumventricular system in the coding of stimuli as potential stressors and in the subsequent activation of requisite systems necessary to provide a sustained, coordinated, and synchronous coping response.

[Morphological studies on cataract and small lens formation in 
neonatal rats treated with monosodium-L-glutamate]. HERE 

[Article in Japanese] Kawamura M, Azuma N, Kohsaka S.
Nippon Ganka Gakkai Zasshi. 1989 May;93(5):562-8.

...The incidence of cataract increased with age, reaching more than 75% at 4 months of age. Morgagni's globules were histologically detected in the opacity of the posterior lens cortex. Degenerative changes of the lens epithelium were observed in the mature cataract. However, the capsules of the lens were well preserved. The size and weight of the lens were smaller than those of controls. Although the pathogenesis of the cataract and small lenses are not clear at the moment, these findings indicate that administration of MSG could be an etiologic factor in cataract formation in the developing rat.

Alteration in Serum Homocysteine Levels upon Ingestion of 
Monosodium Glutamate (MSG) to Adult Male Rats - HERE

Jyoti Sharma, Kuldip Singh, Pushpa Ahluwalia, Arvind Preet Kaur
Article · December 2009

...A study revealed a significant increase in serum homocysteine levels by 27.06% (p<0.01) and 73.98% (p<0.001) in 4 mg monosodium glutamate per gram body weight (Group-2) and 8 mg per gram body weight monosodium glutamate (Group-3) treated animals compared to normal animals. These observations suggested that ingestion of monosodium glutamate at dose level of 4 mg/g body weight and 8 mg/g body weight produced hyperhomocysteinemia and thereby could initiate atherothrombosis.

Effect of aspartame plus monosodium L-glutamate ingestion on plasma and 
erythrocyte amino acid levels in normal adult subjects fed a high protein meal. HERE

Stegink LD, Filer LJ Jr, Baker GL.
Am J Clin Nutr. 1982 Dec;36(6):1145-52.

...Plasma phenylalanine concentrations were significantly higher (p less than 0.05, paired t test) after ingestion of meals containing aspartame plus glutamate reflecting the increased phenylalanine load.

Monosodium glutamate induced nociception and oxidative stress dependent on time of administration, age of rats and susceptibility of spinal cord and brain regions - HERE

Suzan Gonçalves, Rosa Pietro Maria Chagas, Ana Paula Pesarico, Cristina Wayne Nogueira
Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, CEP 97105-900 Santa Maria, Rio Grande do Sul, Brazil
Toxicology and Applied Pharmacology | Volume 351, 15 July 2018, Pages 64-73

...These findings demonstrate that nociception and oxidative stress was induced in rats dependent on the time of MSG administration, susceptibility of spinal cord and brain regions and the age of rats.

Effect of different doses of monosodium glutamate on the thyroid 
follicular cells of adult male albino rats: a histological study - HERE

Hanaa A Khalaf(1), Eetmad A Arafat(1,2)
1 Department of Histology, Faculty of Medicine, Mansoura University, Egypt
2 Departement of Anatomy, Taif University, KSA
Address correspondence to: Hanaa A Khalaf, Department of Histology and Cell Biology, Faculty of Medicine, Mansoura University, Egypt
International Journal of  Clinical & Experimental Pathology. 2015; 8(12): 15498–15510.

...The results displayed that MSG even at low doses is capable of producing alterations in the body weights and thyroid tissue function and histology.

212 Effects of Monosodium Glutamate on Nursery Pig Performance. HERE

A B Lerner, Michael D.Tokach, J M DeRouchey, Steve Dritz
J. Anim. Sci Vol. 96, Suppl. S2

...Increasing MSG resulted in poorer G:F (linear, P=0.003; 0.670, 0.660, 0.654, 0.654, and 0.645, respectively; SEM=0.0057) for phase 3. Thus, for the overall nursery period, G:F tended (quadratic, P=0.080) to be poorer with increasing MSG. In conclusion, MSG did not improve nursery pig performance and MSG may reduce intake and gain when dietary Na is not balanced.

Plasma lipoproteins of monosodium glutamate-induced obese rats. HERE

Oida K, Nakai T, Hayashi T, Miyabo S, Takeda R.
Int J Obes. 1984;8(5):385-91.

... The MSG-treated rats, in addition to being stunted and having enlarged adipose tissue stores, showed reduced body weight and food intake. These rats revealed a marked increase of plasma triglyceride and a slight but significant increase of phospholipids in both male and female... Plasma insulin level was higher in male MSG-treated rats (49.3 +/- 6.6 microU/ml [s.e.]) than in female MSG-treated rats (14.3 +/- 3.2 microU/ml) or in male control rats (34.6 +/- 6.6 microU/ml). These results suggested that hyperinsulinemia plays an important role in the increase of VLDL observed in the MSG-treated male rats.

Obesity induced by neonatal monosodium glutamate treatment in spontaneously 
hypertensive rats: an animal model of multiple risk factors. HERE

Iwase M(1), Yamamoto M, Iino K, Ichikawa K, Shinohara N, Yoshinari M, Fujishima M.
1 Second Department of Internal Medicine, Kyushu University, Fukuoka, Japan.
Hypertens Res. 1998 Mar;21(1):1-6.

Abstract
The present study was designed to develop an animal model of multiple risk factors, including obesity, hypertension, non-insulin-dependent diabetes mellitus, and hyperlipidemia. Hypothalamic obesity was induced by neonatal monosodium glutamate (MSG) treatment in spontaneously hypertensive rats (SHR). Female newborn SHR were treated intraperitoneally with 2 or 4 mg/kg body weight of MSG for 5 days. Obesity developed in SHR treated with 4 mg/kg of MSG but not in SHR treated with 2 mg/kg of MSG. Obese SHR had impaired glucose tolerance, hyperinsulinemia, and hypertriglyceridemia. However, the severity of hypertension was attenuated in obese SHR as compared with control SHR. The degree of obesity was closely related to the metabolic abnormalities, but inversely correlated with the blood pressure level. Macrovascular changes were investigated in obese SHR at 14 months of age. Intimal thickening was accelerated in the carotid artery of obese SHR as compared with that of nonobese SHR. Aortic contents of DNA and total cholesterol were significantly increased in obese SHR. SHR associated with MSG-induced obesity showed major manifestations of metabolic syndrome X. This animal model may be useful to study the clustering of risk factors for the development of macrovascular diseases.

Monosodium Glutamate (MSG) Consumption Is Associated with 
Urolithiasis and Urinary Tract Obstruction in Rats - HERE (pdf available)

Amod Sharma (1), Vitoon Prasongwattana (1), Ubon Cha’on (1)*, Carlo Selmi (2,3), Wiphawi Hipkaeo(4), Piyanard Boonnate (1), Supattra Pethlert (1), Tanin Titipungul (5), Piyapharom Intarawichian (6), Sakda Waraasawapati (6), Anucha Puapiroj (6), Visith Sitprija (7), Sirirat Reungjui (8)
1 Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand,
2 Rheumatology and Clinical Immunology, Humanitas Clinical and Research Center, Milan, Italy,
3 BIOMETRA Department, University of Milan, Milan, Italy,
4 Department of Anatomy, Faculty of Medicine, Khon Kaen, University, Khon Kaen, Thailand,
5 Department of Pathology, Mahasarakham Hospital, Mahasarakham, Thailand,
6 Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand,
7 Queen Saovabha Memorial Institute, Bangkok, Thailand,
8 Department of Internal Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
PLoS ONE 8(9):e75546 · September 2013

 ...MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion. Oral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies.

Monosodium Glutamate Dietary Consumption Decreases 
Pancreatic β-Cell Mass in Adult Wistar Rats - HERE (pdf available)

Piyanard Boonnate(1), Sakda Waraasawapati(2), Wiphawi Hipkaeo(3), Supattra Pethlert(1), Amod Sharma(1), Carlo Selmi(4,5), Vitoon Prasongwattana(1), Ubon Cha’on(1)
1 Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand,
2 Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand, 3 Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand, 4 Rheumatology and Clinical Immunology, Humanitas Clinical and Research Center, Milan, Italy, 5 Rheumatology, Allergy, and Clinical Immunology, University of California Davis, Davis, California, United States of America
PLoS ONE · June 2015

...Conclusion: Daily MSG dietary consumption was associated with reduced pancreatic β-cell mass and enhanced hemorrhages and fibrosis, but did not affect glucose homeostasis. We speculate that high dietary MSG intake may exert a negative effect on the pancreas and such effect might become functionally significant in the presence or susceptibility to diabetes or NaCl; future experiments will take these crucial cofactors into account.

Research Article
Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity - HERE (pdf)

Kazuhiko Nakadate(1), Kento Motojima(2), Tomoya Hirakawa(2), and Sawako Tanaka-Nakadate(3)
1 Department of Basic Science, Educational and Research Center for Pharmacy, Meiji Pharmaceutical University, Tokyo 204-8588, Japan
2 Faculty of Pharmaceutical Sciences, Meiji Pharmaceutical University, Tokyo 204-8588, Japan
3 Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan

...5. Conclusions
There was a decrease in hematoxylin-stained regions in the small intestinal epithelium of obese mice compared with controls. Furthermore, electron microscopy revealed a decrease in numbers and shortening of rER in the small intestinal epithelium of the obese mice. These results suggest that
dysfunction of the small intestinal epithelium could occur in chronic obesity starting in childhood. Moreover, dysfunction of the small intestinal epithelium could affect functions such as protein synthesis and the defense mechanism that prevents the invasion of pathogenic microbes. These mechanisms could be involved in the pathogenesis of serious disorders associated with chronic obesity starting in childhood.

Neonatal treatment with monosodium glutamate: effects of prolonged growth hormone (GH)-releasing hormone deficiency on pulsatile GH secretion and growth in female rats. HERE

Maiter D(1), Underwood LE, Martin JB, Koenig JI.
1 Department of Neurology, Massachusetts General Hospital, Boston.
Endocrinology. 1991 Feb;128(2):1100-6.

...Compared to controls, treatment with MSG led to a marked inhibition (by 90%) of GH secretion in both sexes. Significant reductions in GH pulse amplitude (-95%) and pulse duration (-62%) were observed in males, whereas pulse amplitude (-85%), pulse frequency (-67%), and baseline GH concentrations (-80%) were markedly reduced in females. The GH responses to an iv bolus injection of rat GHRH (1 microgram/rat) was severely blunted in both male and female MSG-treated rats. This study demonstrates that GHRH deficiency in female rats results in a marked inhibition of GH pulses, as in males, but also causes severe and sex-specific reductions in GH basal secretion and pulse frequency. These observations suggest that hypothalamic GHRH secretion in female rats is more continuous than in males and is a determinant of the elevated interpulse secretion of GH. Moreover, body wt and linear growth are less severely affected by arcuate lesions in female animals, compared to males. These sex-related differences in growth rates may result in part from the tendency of female MSG-lesioned rats to become more obese than males, and the development of obesity, in turn, may antagonize the factors that tend to slow linear growth.

Alterations in the lipid profile and liver enzymes of rats 
treated with monosodium glutamate - HERE (pdf)

BS Okediran 1, AE Olurotimi2, SA Rahman1, OG Michael3& JO Olukunle1
1 Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, University of Agriculture, Abeokuta, Nigeria.
2 Department of Veterinary Anatomy, College of Veterinary Medicine, University of Agriculture, Abeokuta, Nigeria.
3 Department of Veterinary Pharmacology and Toxicology, University of Abuja, Abuja, Nigeria
Sokoto Journal of Veterinary Sciences, Volume 12 (Number 3). December, 2015

...There was significant increase (P<0.05) in aminotransferases i.e. alanine and aspartate aminotransferases as well as increase in total plasma cholesterol and low density lipoprotein cholesterol most obvious at higher dose of 1.0g of monosodium glutamate. Though there was decrease in plasma protein concentration, triglyceride and high density lipoprotein cholesterol which was not
statistically significant, therefore monosodium glutamate has both hepatotoxic and dyslipidaemia effects due to its alterations in both aminotransferase activities and lipid profile, hence monosodium glutamate though a flavor enhancer food additive but it must be carefully used in food preparation due to it alterations in both the liver enzymes and the lipid profile.

Obesity induced by neonatal treatment with monosodium glutamate impairs 
microvascular reactivity in adult rats: Role of NO and prostanoids - HERE (pdf)

N.S. Lobato (a), F.P. Filgueira (a), E.H. Akamine (a), A.P.C. Davel (b), L.V. Rossoni (b), R.C. Tostes (a), M.H.C. Carvalho (a), Z.B. Fortes (a)
*
a Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, Brazil
b Department of Physiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
Nutrition, Metabolism & Cardiovascular Diseases (2010) xx, 1e9

...Conclusion: Obesity/insulin resistance has a detrimental impact on vascular function. Reduced
NO bioavailability and increased ROS generation from uncoupled eNOS and imbalanced release
of COX products from COX-2 play a critical role in the development of these vascular alterations.

Article
Chronic Monosodium Glutamate Administration Induced Hyperalgesia in Mice - HERE (pdf)

Anca Zanfirescu, Aurelia Nicoleta Cristea, George Mihai Nitulescu ID , Bruno Stefan Velescu
and Daniela Gradinaru
Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, TraianVuia 6, 020956 Bucharest, Romania.

...We also tried to determine if a correlation between chronic administration of MSG and variations in central nitric oxide (NO) concentration could be established. We found that a dose of 300 mg/kg MSG given for 21 days reduces the pain threshold and is associated with a significant increase in brain NO level. The implications of these findings on food additive-drug interaction, and on pain perception in healthy humans, as well as in those suffering from affections involving chronic pain, are still to be investigated.

Pituitary responsiveness to LHRH stimulation in hamsters 
treated neonatally with monosodium glutamate. HERE

Lamperti AA, Baldwin DM.
Neuroendocrinology. 1982 Mar;34(3):169-74.

...These results suggest that the decreased basal FSH levels and the attenuated FSH response to LHRH observed in vivo in MSG-treated animals may be due to an alteration in a neural or extraneural component which is involved in regulating the release of FSH by LHRH and which is evident in the absence of a functional arcuate nucleus and/or develops directly as the result of the neonatal administration of MSG.

The toxic effects of monosodium glutamate (MSG) – The involvement 
of nitric oxide, prostanoids and potassium channels in 
the reactivity of thoracic arteries in MSG-obese rats - HERE

Michał Majewski(a), Adam Jurgoński(b), Bartosz Fotschki(b), JerzyJuśkiewicz(b)
a Department of Pharmacology and Toxicology, Faculty of Medicine, UWM, Olsztyn, Poland
b Division of Food Science, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
Toxicology and Applied Pharmacology | Volume 359, 15 November 2018, Pages 62-69

...Our findings suggest that increased prostanoid production and hypersensitivity to thromboxane A2 together with down-regulation of potassium channels and low nitric oxide bioavailability may contribute to the increase in blood pressure found in adult MSG-obese male rats.

Chronic Administration of Monosodium Glutamate under Chronic Variable Stress Impaired Hypothalamic-Pituitary-Adrenal Axis Function in Rats - HERE (pdf)

Hee Jeong Seo(1), Hyang-Do Ham(1), Hyung Yong Jin(1), Woo Hyung Lee(1), Hyun Sub Hwang(1), Soon-Ah Park(2), Yong Sung Kim(3), Suck Chei Choi(3), Seoul Lee(3), Kyung Jae Oh(3), Byung Sook Kim(4), Byung Rim Park(1), and Moon Young Lee(1)
1 Department of Physiology and Digestive Disease Research Institute,
2 Department of Nuclear Medicine,
3 Institute of Wonkwang Medical Science, School of Medicine, Wonkwang University, Iksan 570-749, 4 Department of Food and Nutrition, Jeonbuk Science College, Iksan
580-712, Korea
Korean J Physiol Pharmacol | Vol 14: 213-221, August, 2010

... In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS+MSG group as compared to all other groups, except the naïve group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

Glucose intolerance in monosodium glutamate obesity is linked 
to hyperglucagonemia and insulin resistance in α cells - HERE

Thiago R. Araujo,  Joel A. da Silva Jr,  Jean F. Vettorazzi,  Israelle N. Freitas,  Camila Lubaczeuski, Emily A. Magalhães,  Juliana N. Silva,  Elane S. Ribeiro,  Antonio C. Boschero,  Everardo M. Carneiro,  Maria L. Bonfleur, Rosane Aparecida Ribeiro
Journal of Cellular Physiology, 14th October, 2018

...Therefore, severe glucose intolerance in MSG‐obese mice was associated with increased hepatic glucose output, in association with hyperglucagonemia, caused by the refractory actions of glucose and insulin in α cells and via an effect that may be due to enhanced mTOR activation.

Small intestine barrier function failure induces systemic inflammation in monosodium glutamate-induced chronically obese mice - HERE (full text and pdf available)

Kazuhiko Nakadate(a), Tomoya Hirakawa(a), Sawako Tanaka-Nakadate(b)
a Department of Basic Science, Educational and Research Center for Pharmacy, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
b Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, 880, Kitakobayashi, Mibu, Shimotsuga, Tochigi 321-0293, Japan.
Applied Physiology, Nutrition, and Metabolism, 2019, 44(6): 587-594

...Numerous gaps were identified between small intestinal epithelial cells in chronically obese mice, and levels of both desmosomal and tight junction proteins were significantly lower in their small intestinal epithelial cells. Moreover, in chronically obese mice, a significant increase in the number of intestinal inflammatory cells, particularly macrophages, was observed; in addition, blood samples from the mouse model show an increase in markers of inflammation, tumor necrosis factor-alpha and interleukin-1-beta. These findings suggest that functional deterioration of adhesion structures between small intestinal epithelial cells causes gastrointestinal barrier function failure, leading to a rise in intestinal permeability to blood vessels and consequent systemic inflammation, characterized by macrophage infiltration.

Hyperresponsiveness to the inhibitory action of dopamine agonists on luteinizing hormone secretion in the monosodium-L-glutamate-treated, orchidectomized rat. HERE

Rose PA, Weick RF.
Neuroendocrinology. 1986;44(1):95-101.

...These findings suggest that the depletion of DA induced by neonatal MSG treatment results in a supersensitivity to DA agonists.

Swim training and the genetic expression of adipokines in 
monosodium glutamatetreated obese rats - HERE (pdf)

Paulo Vinicius Svidnicki(1), Nayara Carvalho Leite(2), Marcelo Ricardo Vicari(1),
Mara Cristina de Almeida(1), Roberto Ferreira Artoni(1),
Giovani Marino Favero(2),Sabrina Grassiolli(2), Viviane Nogaroto(1)
1 Department of Structural, Molecular and Genetic Biology, Universidade Estadual de Ponta Grossa (UEPG)
Arch Endocrinol Metab. 2015;59(3):210-4

...Conclusions: In conclusion, regular physical activity was not capable to correct the expression of proinflammatory adipokines in MSG-obese rat adipocytes. 

Effect of the oral administration of monosodium glutamate during pregnancy and breast-feeding in the offspring of pregnant Wistar rats - HERE (pdf available)

Vinicius von Diemen & Manoel Roberto Maciel Trindade
Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 25(1):37-42 · February 2010

...MSG presented a dose-dependent relation in the variables weight and NAL. It caused a decrease in the growth pattern as well as in the weight gain pattern until the 21st day of life. The IL of the group 20% had an increased in relation to the control group after 3 weeks of follow up.

Effects of food flavour enhancer (Monosodium Glutamate and Maggi Poulet) 
supplementation on glucose tolerance in Sprague Dawley rat - HERE

MN Tchaou, C Lamboni, K Eklu-Gadegbeku, E Abalokoka, A Aklikokou
International Journal of Biological and Chemical Sciences | Vol 7, No 1, 2013

...All changes observed in the glycemia of rats in experimental groups do not allow to qualify them to be glucose intolerant, nevertheless monosodium glutamate consumption in association or not with high fat is hepatotoxic and may contribute to the emergence of prediabetes in human being.

Histological studies of the effects of monosodium glutamate of the 
fallopian tubes of adult female Wistar rats - HERE

Andrew Osayame Eweka, Abieyuwa Eweka, and Ferdinard A.E. Om’Iniabohs
Department of Anatomy, School of Basic Medical Sciences, College of Medical Sciences, University of Benin, Benin City, Edo State, Nigeria
North American Journal of Medical Sciences. 2010 Mar; 2(3): 146–149.

...Result:
The histological findings in the treated groups showed evidence of cellular hypertrophy, degenerative and atrophic changes, and lysed red blood cells in lumen with the group that received 0.08mg/kg of monosodium glutamate more severe.

Conclusion:
MSG may have some deleterious effects on the fallopian tubes of adult female Wistar rats at higher doses and by extension may contribute to the causes of female infertility. It is recommended that further studies aimed at corroborating these findings be carried out.

Monosodium glutamate daily oral supplementation: study of its effects 
on male reproductive system on rat model - HERE

Fatin Farhana Jubaidi, Ramya Dewi Mathialagan, Mahanem Mat Noor,Izatus Shima Taib &Siti Balkis Budin ORCID Icon
Systems Biology in Reproductive Medicine | Volume 65, 2019 - Issue 3 Pages 194-204 

...Previous studies had reported on effects of MSG when given at extremely high dosages, the results are not applicable to human equivalent intake. Therefore, the present study aimed to evaluate the effect of MSG on sperm quality and changes in reproductive organs of adult male rats when taken at average human daily intake (ADI)... A significant decrease in the weight of reproductive organs was also apparent (p < 0.05). Moreover, oxidative status evaluation showed that treatment of MSG induces oxidative stress in the testis, more severely at a dose of 120 mg/kg body weight. These findings are supported by alterations in the observed histology of reproductive organs. This study shows that an intake dose of 120 mg/kg body weight MSG could cause significant damage to the reproductive system.

Measurement of oxygen consumption and locomotor activity in 
monosodium glutamate-induced obesity. HERE

Poon TK, Cameron DP.
Am J Physiol. 1978 May;234(5):E532-4.

Abstract
Oxygen consumption and locomotor activity were studied in mice developing obesity after neonatal administration of monosodium glutamate (MSG) and in untreated controls. MSG-treated mice became obese in the absence of increased food intake. Locomotor activity was significantly less in MSG-treated mice 2, 10, and 20 wk after weaning. Oxygen consumption expressed in terms of the Lee index was not significantly different at 2 wk after weaning although at 10 and 20 wk it was significantly lower in MSG-treated mice. Plasma thyroxine was not different between MSG-treated and control mice. It is suggested that diminished energy expenditure is the major factor in the etiology of obesity after neonatal administration of MSG.

Resistance exercise reduces memory impairment induced by 
monosodium glutamate in male and female rats - HERE (pdf)

Paulo Cesar Oliveira Araujo, Caroline Brandao Quines, Nat ˜ alia Silva Jardim, Marlon Regis Leite ´
and Cristina Wayne Nogueira
Laboratorio de Sıntese, Reatividade e Avaliacao Farmacologica e Toxicologica de Organocalcogenios, Departamento de Bioqu´ımica e Biologia Molecular,
Centro de Ciˆencias Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brasil
Experimental Physiology | 102.7 (2017) pp 845–853

...What is the central question of this study?
Monosodium glutamate causes cognitive impairment. Does resistance exercise improve the
performance of rats treated with monosodium glutamate?...
This study demonstrates that MSG affected the memory of male and female rats in different ways. Resistance exercise was effective against the decrease in recognition for male rats and in location memory for female rats treated with MSG. This report demonstrates the beneficial effects of resistance exercise against the prejudice of motor condition and impairment of memory induced by MSG in male and female rats.

Cytochemical studies demonstrating the effect of monosodium 
glutamate on RNA concentration in neurons in mice. HERE

Dhindsa KS.
Acta Anat (Basel). 1983;116(3):201-5.

Abstract
The effect of monosodium glutamate (MSG) on the concentration of ribonucleic acid (RNA) in the neurons of mice was studied, using the specific cytochemical stain, azure B bromide. The RNA-rich sites such as the nucleolus and the Nissl substances of large neurons showed a marked decrease in the concentration of RNA in the MSG-treated as compared to the control animals. Since RNA is believed to be the principal macromolecule involved in the learning and behavioral processes, previous reports have attributed learning and behavioral dysfunctions in MSG-treated animals to a significant decrease of the RNA concentration in these animals.

Effect of monosodium glutamate and aspartame on behavioral and 
biochemical parameters of male albino mice - HERE (pdf available)

Gasem M. Abu - Taweel
AFRICAN JOURNAL OF BIOTECHNOLOGY 15(15):601-612 · April 2016

...In conclusion, the current study indicated that exposure to food additives MSA and ASM was dangerous to mice in relation to behavior and biochemical analysis. In addition, these food additives need more scientific researches to investigate their effect on other parameters.

Neonatal Monosodium Glutamate Administration Disrupts Place Learning and Alters Hippocampal–Prefrontal Learning-Related Theta Activity in the Adult Rat - HERE

Miguel ÁngelLópez-Vázquez(a), Carla Estefanía Gama-García(b), Yoana Estrada Reyes(a), Lorena Gaytán-Tocavén(b), José Miguel Cervantes Alfaro(c), María Esther Olvera-Cortés(b)
a Laboratorio de Neuroplasticidad de los Procesos Cognitivos, División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Camino de la Arboleda 300, Ex-Hacienda de San José de la Huerta, C.P., 58341, Morelia, Michoacán, México
b Laboratorio de Neurofisiología Experimental, División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Camino de la Arboleda 300, Ex-Hacienda de San José de la Huerta, C.P., 58341, Morelia, Michoacán, México
c Laboratorio de Neurociencias, Departamento de Postgrado, Facultad de Medicina “Dr. Ignacio Chávez”, Universidad Michoacana de San Nicolás de Hidalgo, Rafael Carrillo esq. Salvador González Herrejón S/N. C.P., 58000, Colonia Centro, Morelia, Michoacán, México
Neuroscience | Volume 414, 21 August 2019, Pages 228-244

...In conclusion, neonatal administration of MSG, which caused a profound deficit in place learning at the adult age, also altered the theta pattern both in the hippocampus and prelimbic cortex.

Cortical tau burden and behavioural dysfunctions in mice 
exposed to monosodium glutamate in early life - HERE

Passainte S. Hassaan, Data curation, Methodology, Writing – original draft,#1 Abeer E. Dief, Conceptualization, Data curation, Methodology, Writing – original draft,#1,* Teshreen M. Zeitoun, Investigation, Methodology, Writing – original draft,#2 Azza M. Baraka, Conceptualization, Methodology, Writing – original draft,3,‡ Robert M. J. Deacon, Conceptualization, Validation, Writing – review & editing,4,‡ and Amany Elshorbagy,
PLoS One. 2019; 14(8)

Abstract
Although monosodium glutamate (MSG)-induced neurotoxicity has been recognized for decades, the potential similarities of the MSG model to Alzheimer’s disease (AD)-type neuropathology have only recently been investigated. MSG-treated mice were examined behaviourally and histologically in relation to some features of AD...The findings point to subcutaneous MSG administration in early life as a cause of tau pathology and compromised species-typical behaviour in rodents. Determining whether MSG can be useful in modelling AD requires further studies of longer duration and full behavioural characterization.

Effect of neonatal exposure of Monosodium Glutamate in kidney 
of albino mice – a Histological study - HERE (pdf)

Bhattacharya T(1), Ghosh SK(2)
1 Deptartment of Anatomy, Medical College Kolkata, India,
2 Department of Anatomy, Nepal Medical College Teaching
Hospital, Kathmandu, Nepal
Nepal Med Coll J 2019; 21(2): 134-41

...This study was done to observe any histological changes in kidneys of albino mice after neonatal exposure with MSG. Study showed significant changes in weight and volume of kidneys in gross morphology. Increased urinary space and dilatation of proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) were constant finding in experimental animals. There were loss of luminal microvilli and reduced height of lining cells of both PCT and DCT.

Dietary consumption of monosodium L-glutamate induces adaptive 
response and reduction in the life span of Drosophila melanogaster. HERE

Abolaji AO(1), Olaiya CO(2), Oluwadahunsi OJ(3), Farombi EO(1).
1 Drug Metabolism and Molecular Toxicology Research Laboratories, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
2 Nutritional and Industrial Biochemistry Research Laboratories, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
3 Department of Biochemistry, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria.
Cell Biochem Funct. 2017 Apr;35(3):164-170. 

...In conclusion, consumption of MSG for 5 days by D. melanogaster induced adaptive response, but long-term exposure reduced life span of flies. This study may therefore have public health significance in humans, and thus, moderate consumption of MSG is advocated by the authors.

Monosodium glutamate restricts the adipogenic potential of 3T3‐L1 
preadipocytes through mitotic clonal expansion - HERE (full text available)

Mehmet Soner Türküner & Ferruh Özcan
Cell Biology International | November 2019

...Our findings warrant further investigations to unravel the effect of long‐term dietary MSG intake on capacity of preadipocytes in different fat depots to undergo mitotic clonal expansion and hyperplasia in rodent models and human subjects, respectively.

A High Dietary Intake of Sodium Glutamate as Flavoring (Ajinomoto)
 Causes Gross Changes in Retinal Morphology and Function - HERE

Hiroshi Ohguro 1, Harumi Katsushima, Ikuyo Maruyama, Tadao Maeda, Satsuki Yanagihashi, Tomomi Metoki, Mitsuru Nakazawa
Exp Eye Res. 2002 Sep;75(3):307-15.

...The present study suggests that a diet with excess sodium glutamate over a period of several years may increase glutamate concentrations in vitreous and may cause retinal cell destruction.

Testicular Protective and Antioxidant Effects of Selenium Nanoparticles on Monosodium Glutamate-Induced Testicular Structure Alterations in Male Mice - HERE

Reham Z Hamza 1 2, Abd El-Aziz A Diab 2
1Biology Department, Faculty of Science, Taif University, Taif, Saudi Arabia.
2Zoology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
Toxicol Rep | 2020 Jan 27;7:254-260

...Results: Results proved that the administration of SeNPs diminished the effect of MSG (LD and HD)-that induced decrease in testosterone hormone levels and elevated oxidative stress markers markedly. SeNPs had a potent antioxidant effect and elevated the antioxidant enzymes significantly and decreased lipid peroxidation markers as compared with MSG either (LD and HD) groups.

Conclusion: It is clear from the data that SeNPs inhibit testicular injury and improve the antioxidant state in male mice.


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