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Sample records for monosodium glutamate msg-obese

  1. Surgical removal of visceral fat decreases plasma free fatty acid and increases insulin sensitivity on liver and peripheral tissue in monosodium glutamate (MSG)-obese rats.

    PubMed

    Kim, Y W; Kim, J Y; Lee, S K

    1999-10-01

    In order to evaluate the role of visceral and subcutaneous fat tissue in insulin sensitivity and lipid metabolism, we measured the fasting levels of plasma free fatty acid (FFA) and insulin, glucose disappearance rate (Rd), and hepatic glucose production rate (HGP) after surgical removal of visceral (VF) or subcutaneous (SF) fat tissue in monosodium glutamate-obese (MSG-Ob) rats. Monosodium glutamate obesity was induced in rats by neonatal injection of MSG. Surgery to remove fat was done at 15 weeks of age. The experiments were done four weeks after the surgery. MSG-Ob rats showed increased levels of FFA, insulin, and HGP and decreased Rd compared to normal rats. In the VF group, the FFA level and HGP were decreased to normal values, Rd was partially normalized, but the level of insulin did not change significantly compared to MSG-Ob. In the SF group, FFA and Rd were partially normalized, but HGP was not suppressed significantly compared to MSG-Ob. These results suggest that visceral fat affects the insulin sensitivity of liver and FFA concentration more than subcutaneous fat; however, no significant difference was shown on whole body insulin sensitivity and fasting insulin concentration. PMID:10576150

  2. Genotoxicity of monosodium glutamate.

    PubMed

    Ataseven, Nazmiye; Yüzbaşıoğlu, Deniz; Keskin, Ayten Çelebi; Ünal, Fatma

    2016-05-01

    Monosodium glutamate (MSG) is one of the most widely used flavor enhancers throughout the world. The aim of this study is to investigate the genotoxic potential of MSG by using chromosome aberrations (CAs), sister-chromatid exchanges (SCEs), cytokinesis-blocked micronucleus (CBMN), and random amplified polymorphic DNA-polimerase chain reaction (RAPD-PCR) in cultured human lymphocytes and alkaline comet assays in isolated human lymphocytes, which were incubated with six concentrations (250, 500, 1000, 2000, 4000 and 8000 μg/mL) of MSG. The result of this study indicated that MSG significantly and dose dependently increased the frequencies of CAs, SCE and MN in all treatments and times, compared with control. However, the replication (RI) and nuclear division indices (NDI) were not affected. In this paper, in vitro genotoxic effects of the MSG was also investigated on human peripheral lymphocytes by analysing the RAPD-PCR with arbitrary 10-mer primers. The changes occurring in RAPD profiles after MSG treatment include increase or decrease in band intensity and gain or loss of bands. In the comet assay, this additive caused DNA damage at all concentrations in isolated human lymphocytes after 1-h in vitro exposure. Our results demonstrate that MSG is genotoxic to the human peripheral blood lymphocytes in vitro. PMID:26929995

  3. The PPARalpha/gamma dual agonist chiglitazar improves insulin resistance and dyslipidemia in MSG obese rats.

    PubMed

    Li, Ping-Ping; Shan, Song; Chen, Yue-Teng; Ning, Zhi-Qiang; Sun, Su-Juan; Liu, Quan; Lu, Xian-Ping; Xie, Ming-Zhi; Shen, Zhu-Fang

    2006-07-01

    1. The aim of this study was to investigate the capacity of chiglitazar to improve insulin resistance and dyslipidemia in monosodium L-glutamate (MSG) obese rats and to determine whether its lipid-lowering effect is mediated through its activation of PPARalpha. 2. Chiglitazar is a PPARalpha/gamma dual agonist. 3. The compound improved impaired insulin and glucose tolerance; decreased plasma insulin level and increased the insulin sensitivity index and decreased HOMA index. Euglycemic hyperinsulinemic clamp studies showed chiglitazar increased the glucose infusion rate in MSG obese rats. 4. Chiglitazar inhibited alanine gluconeogenesis, lowered the hepatic glycogen level in MSG obese rats. Like rosiglitazone, chiglitazar promoted the differentiation of adipocytes and decreased the maximal diameter of adipocytes. In addition, chiglitazar decreased the fibrosis and lipid accumulation in the islets and increased the size of islets. 5. Chiglitazar reduced plasma triglyceride, total cholesterol (TCHO), nonesterified fatty acids (NEFA) and low density lipoprotein-cholesterol levels; lowered hepatic triglyceride and TCHO contents; decreased muscular NEFA level. Unlike rosiglitazone, chiglitazar showed significant increase of mRNA expression of PPARalpha, CPT1, BIFEZ, ACO and CYP4A10 in the liver of MSG obese rats. 6. These data suggest that PPARalpha/gamma coagonist, such as chiglitazar, affect lipid homeostasis with different mechanisms from rosiglitazone, chiglitazar may have better effects on lipid homeostasis in diabetic patients than selective PPARgamma agonists. PMID:16751799

  4. Anorexigenic effect of cholecystokinin is lost but that of CART (Cocaine and Amphetamine Regulated Transcript) peptide is preserved in monosodium glutamate obese mice.

    PubMed

    Zelezná, B; Maixnerová, J; Matysková, R; Haugvicová, R; Blokesová, D; Maletínská, L

    2009-01-01

    Monosodium glutamate (MSG) treatment of neonatal mice results in a selective damage to the arcuate nucleus (ARC) and development of obesity with increased adiposity at sustained body weight in the adulthood. Feeding pattern of the MSG obese mice is unusual. Our previous results showed that after 24-h fasting, MSG mice consumed negligible amount of food in several hours and therefore, it was impossible to register the effect of peptides attenuating food intake such as cholecystokinin (CCK) or cocaine- and amphetamine-regulated transcript (CART) peptide. To overcome this problem, two findings were used: firstly, orexigenic effect of neuropeptide Y (NPY) was attenuated both by CCK or CART peptide in lean fed mice and secondly, orexigenic effect of NPY was preserved in fed rats with MSG obesity. In this study, short-term food intake in fed lean and MSG obese C57BL/6 male mice was measured after simultaneous central administration of orexigenic NPY with either CART peptide or peripherally administered CCK. Anorexigenic action of exogenous CART peptide was preserved in MSG obese mice. On the other hand, satiety effect of exogenous CCK was completely lost in MSG obese mice. In conclusion, effective leptin signaling in ARC is necessary for satiety effect of CCK. PMID:19093718

  5. [A preliminary study on the mechanism of impaired beta cell function in monosodium glutamate obese rat with insulin resistance].

    PubMed

    Liu, Shuai-Nan; Liu, Quan; Shen, Zhu-Fang

    2008-11-01

    This study is to evaluate beta cell function and investigate the mechanism of impaired pancreatic islet beta cell function in monosodium glutamate (MSG) obese rat with insulin resistance, an animal model of metabolic syndrome. Insulin tolerance test was used to screen MSG obese rats with insulin resistance. Blood concentrations of glucose, triglyceride, total cholesterol and insulin were determined. Beta cell function was assessed with hyperglycemic clamp technique. The morphological alterations in pancreas and changes of islet beta cell mass were evaluated by hematoxylin-eosin (HE) and Gomori aldehyde fuchsin staining. Lipid, oxidative stress relevant factors, nitric oxide (NO) level and activity of ATPase in pancreas and pancreatic mitochondrial were tested. The MSG obese rats with insulin resistance could be validated as a typical metabolic syndrome animal model possessing increased fasting plasma triglycerides and insulin (P < 0. 001), markedly decreased weight indices of pancreas and impaired glucose-stimulated insulin secretion. Hematoxylin-eosin (HE) and Gomori aldehyde fuchsin staining showed increased adipocytes and fibroplasia deposition in pancreas and reduced beta cell mass. The increased contents of triglyceride and NO level, the decreased SOD levels and activities of total ATPase (P < 0.001), Na+-K+-ATPase (P < 0.001) and Ca2+-Mg2+-ATPase (P < 0.01) were observed in pancreas and its mitochondria versus normal rat. The study demonstrates that accumulation of lipids in pancreas could lead to increased systemic indicators of inflammation, such as NO, which may influence the activities of several kinds of ATPase in cell membranes and interfere the ion transport, substance metabolism and energy production in pancreas. Finally the MSG obese rats characterized with metabolic syndrome displayed an impairment of beta cell function. PMID:19239028

  6. Renal sympathetic nerve activity is increased in monosodium glutamate induced hyperadipose rats.

    PubMed

    da Silva Mattos, Alexandro Márcio; Xavier, Carlos Henrique; Karlen-Amarante, Marlusa; da Cunha, Natália Veronez; Fontes, Marco Antonio Peliky; Martins-Pinge, Marli Cardoso

    2012-08-01

    The literature suggests that both obesity and hypertension are associated with increased sympathetic nerve activity. In the present study we evaluated the renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) in hyperadipose rats induced by neonatal administration of monosodium glutamate (MSG). Neonatal Wistar male rats were injected with MSG (4 mg/g body weight ID) or equimolar saline (control) for 5 days. At 90th day, all rats were anesthetized (urethane 1.4 g/kg) and prepared for MAP, HR and renal sympathetic nerve activity recordings. The anesthetized MSG rats presented baseline hypertension and increased baseline RSNA compared with control. Our results suggest the involvement of the renal sympathetic nervous system in the physiopathology of the MSG obesity. PMID:22705582

  7. Anorexigenic lipopeptides ameliorate central insulin signaling and attenuate tau phosphorylation in hippocampi of mice with monosodium glutamate-induced obesity.

    PubMed

    Špolcová, Andrea; Mikulášková, Barbora; Holubová, Martina; Nagelová, Veronika; Pirnik, Zdenko; Zemenová, Jana; Haluzík, Martin; Železná, Blanka; Galas, Marie-Christine; Maletínská, Lenka

    2015-01-01

    Numerous epidemiological and experimental studies have demonstrated that patients who suffer from metabolic disorders, such as type 2 diabetes mellitus (T2DM) or obesity, have higher risks of cognitive dysfunction and of Alzheimer's disease (AD). Impaired insulin signaling in the brain could contribute to the formation of neurofibrillary tangles, which contain an abnormally hyperphosphorylated tau protein. This study aimed to determine whether potential tau hyperphosphorylation could be detected in an obesity-induced pre-diabetes state and whether anorexigenic agents could affect this state. We demonstrated that 6-month-old mice with monosodium glutamate (MSG) obesity, which represent a model of obesity-induced pre-diabetes, had increased tau phosphorylation at Ser396 and Thr231 in the hippocampus compared with the controls, as determined by western blots. Two weeks of subcutaneous treatment with a lipidized analog of prolactin-releasing peptide (palm-PrRP31) or with the T2DM drug liraglutide, which both had a central anorexigenic effect, resulted in increased phosphorylation of the insulin cascade kinases PDK1 (Ser241), Akt (Thr308), and GSK-3β (Ser9). Furthermore, these drugs attenuated phosphorylation at Ser396, Thr231, and Thr212 of tau and of the primary tau kinases in the hippocampi of 6-month-old MSG-obese mice. We identified tau hyperphosphorylation in the obesity-induced pre-diabetes state in MSG-obese mice and demonstrated the beneficial effects of palm-PrRP31 and liraglutide, both of known central anorexigenic effects, on hippocampal insulin signaling and on tau phosphorylation. PMID:25624414

  8. Altered baroreflex and autonomic modulation in monosodium glutamate-induced hyperadipose rats.

    PubMed

    Karlen-Amarante, Marlusa; da Cunha, Natália Veronez; de Andrade, Ozahyr; de Souza, Hugo Celso Dutra; Martins-Pinge, Marli Cardoso

    2012-10-01

    We aimed to examine the cardiovascular function by tonic and baroreflex alterations in obese rats induced by monosodium glutamate (MSG). Neonatal male Wistar rats were injected with MSG (4 mg/g body weight) or equimolar saline (control, C). At 90 days, all rats were anesthetized for catheterization of the femoral artery for mean arterial pressure (MAP) and heart rate (HR) recordings in the conscious state. After baseline, we performed IV treatment with hexamethonium (25 mg/kg), or atropine (1 mg/kg) or propranolol (3 mg/kg). We also performed the spectral analysis of heart rate variability (HRV) and baroreflex sensitivity. Baseline comparison showed that obese rats are hypertensive compared with control (C=110±2 mmHg; MSG=: 123±3 mmHg, P<0.05). After ganglionic blockade with hexamethonium the differences in MAP between control and obese rats disappeared. Beta adrenergic blockade with propranolol induced a greater decrease in heart rate compared with control. The analysis of HRV showed that obese rats have increased modulation by both components of the autonomic nervous system compared with control rats. The baroreflex gain showed increased sensitivity for the parasympathetic component in the obese rats (C=-2.41±0.25; MSG=-3.34±0.23 bpm/mmHg) compared with control. Our data suggest that both components of autonomic cardiac tonus and the parasympathetic component of the baroreflex sensitivity are increased in the MSG obese rat. It is possible that the parasympathetic alterations observed in these MSG obese rats may have originated from central areas of cardiovascular control. PMID:22554831

  9. Current clinical findings on monosodium glutamate.

    PubMed

    Livingstone, V H

    1981-07-01

    Monosodium glutamate (MSG) is a common and widely used food additive which has been passed as GRAS (generally recognized as safe) by the American Food and Drug Administration. However, it may have a significant adverse effect on certain individuals; the physician must be able to recognize the symptoms of MSG sensitivity, otherwise known as "Chinese Restaurant Syndrome". This article reviews current findings on MSG. PMID:21289773

  10. Effects of fibre-enriched diets on tissue lipid profiles of MSG obese rats.

    PubMed

    Rotimi, O A; Olayiwola, I O; Ademuyiwa, O; Balogun, E A

    2012-11-01

    In order to investigate the influence of some fibre-enriched diets on tissue lipids in an animal model of obesity induced by the administration of monosodium glutamate (MSG), obese rats were fed diets containing 30% of Acha, Cassava, Maize and Plantain for five weeks and weight gain, feed intake and lee index were recorded. The lipid profiles of plasma, erythrocytes, kidney, heart and liver as well as hepatic 3-hydroxyl-3-methylglutaryl-CoA (HMG-CoA) reductase activity were measured. The diets significantly (p<0.05) reduced weight gain and lee index in the obese rats. Obesity-induced increase in plasma and erythrocytes lipid levels was significantly (p<0.05) reduced by these diets. MSG-induced obesity also resulted in a significant increase (p<0.05) in hepatic cholesterol level which was reduced by the diets. MSG-obesity was characterised by a significant (p<0.05) increase in cholesterol, triacylglycerol and phospholipids in kidney and this was reversed by the diets except Maize which did not reverse the increased cholesterol level. Only Acha reversed the obesity-induced increase in heart cholesterol and phospholipids. The increased activity of hepatic HMG-CoA reductase associated with obesity was also significantly (p<0.05) reduced by the diets. In conclusion, dyslipidemia associated with MSG-induced obesity could be attenuated by consumption of fibre-enriched diets. PMID:22898616

  11. The safety evaluation of monosodium glutamate.

    PubMed

    Walker, R; Lupien, J R

    2000-04-01

    L-Glutamic acid and its ammonium, calcium, monosodium and potassium salts were evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1988. The Committee noted that intestinal and hepatic metabolism results in elevation of levels in systemic circulation only after extremely high doses given by gavage (>30mg/kg body weight). Ingestion of monosodium glutamate (MSG) was not associated with elevated levels in maternal milk, and glutamate did not readily pass the placental barrier. Human infants metabolized glutamate similarly to adults. Conventional toxicity studies using dietary administration of MSG in several species did not reveal any specific toxic or carcinogenic effects nor were there any adverse outcomes in reproduction and teratology studies. Attention was paid to central nervous system lesions produced in several species after parenteral administration of MSG or as a consequence of very high doses by gavage. Comparative studies indicated that the neonatal mouse was most sensitive to neuronal injury; older animals and other species (including primates) were less so. Blood levels of glutamate associated with lesions of the hypothalamus in the neonatal mouse were not approached in humans even after bolus doses of 10 g MSG in drinking water. Because human studies failed to confirm an involvement of MSG in "Chinese Restaurant Syndrome" or other idiosyncratic intolerance, the JECFA allocated an "acceptable daily intake (ADI) not specified" to glutamic acid and its salts. No additional risk to infants was indicated. The Scientific Committee for Food (SCF) of the European Commission reached a similar evaluation in 1991. The conclusions of a subsequent review by the Federation of American Societies for Experimental Biology (FASEB) and the Federal Drug Administration (FDA) did not discount the existence of a sensitive subpopulation but otherwise concurred with the safety evaluation of JECFA and the SCF. PMID:10736380

  12. 78 FR 76321 - Monosodium Glutamate From China and Indonesia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... Register of September 20, 2013 (78 FR 57881). The conference was held in Washington, DC, on October 23... COMMISSION Monosodium Glutamate From China and Indonesia Determinations On the basis of the record \\1... injured by reason of imports from China and Indonesia of monosodium glutamate, provided for in...

  13. Does monosodium glutamate cause flushing (or merely "glutamania")?

    PubMed

    Wilkin, J K

    1986-08-01

    Monosodium glutamate is widely regarded as the provocative agent in the "Chinese restaurant syndrome," of which flushing is regarded as part of the reaction. Six subjects were monitored by laser Doppler velocimetry for changes in facial cutaneous blood flow during challenge with monosodium glutamate and its cyclization product, pyroglutamate. Additionally, records of patients challenged with monosodium glutamate in the laboratory were reviewed. No flushing was provoked among the twenty-four people tested, eighteen of whom gave a positive history of Chinese restaurant syndrome flushing. These results indicate that monosodium glutamate-provoked flushing, if it exists at all, must be rare. Monosodium glutamate and its cyclization product, pyroglutamate, may provoke edema and associated symptoms. PMID:3745527

  14. Monosodium glutamate 'allergy': menace or myth?

    PubMed

    Williams, A N; Woessner, K M

    2009-05-01

    Monosodium glutamate (MSG) is a salt form of a non-essential amino acid commonly used as a food additive for its unique flavour enhancing qualities. Since the first description of the 'Monosodium glutamate symptom complex', originally described in 1968 as the 'Chinese restaurant syndrome', a number of anecdotal reports and small clinical studies of variable quality have attributed a variety of symptoms to the dietary ingestion of MSG. Descriptions of MSG-induced asthma, urticaria, angio-oedema, and rhinitis have prompted some to suggest that MSG should be an aetiologic consideration in patients presenting with these conditions. This review prevents a critical review of the available literature related to the possible role of MSG in the so-called 'Chinese restaurant syndrome' and in eliciting asthmatic bronchospasm, urticaria, angio-oedema, and rhinitis. Despite concerns raised by early reports, decades of research have failed to demonstrate a clear and consistent relationship between MSG ingestion and the development of these conditions. PMID:19389112

  15. Reproductive alterations in hyperinsulinemic but normoandrogenic MSG obese female rats.

    PubMed

    Gaspar, Renato Simões; Benevides, Renata Ohana Alves; Fontelles, João Lucas de Lima; Vale, Caroline Castro; França, Lucas Martins; Barros, Paulo de Tarso Silva; Paes, Antonio Marcus de Andrade

    2016-05-01

    Obesity and metabolic syndrome are the common causes of reproductive and fertility disorders in women. In particular, polycystic ovary syndrome, which is clinically characterized by hyperandrogenism, oligo/anovulation, and polycystic ovarian morphology, has been increasingly associated with metabolic disorders. However, given the broad interplay between metabolic and reproductive functions, this remains a field of intense research. In this study, we investigated the effect of monosodium l-glutamate (MSG)-induced obesity on reproductive biology of female rats. Newborn female rats were subcutaneously injected with MSG (4g/kg/day) or equiosmolar saline (CTR) each 2 days up to postnatal day (pnd) 10. On pnd 60, estrous cycle was evaluated using vaginal smears twice a day for 15 days, which showed MSG rats to be oligocyclic. Thereafter, animals were killed on estrous phase for blood and tissue collection. MSG rats had increased body mass, accumulation of retroperitoneal and visceral fat pads, and visceral adipocyte hypertrophy compared with CTR rats. MSG rats were also dyslipidemic and hyperinsulinemic but were normoglycemic and normoandrogenic. Ovarian morphology analysis showed that MSG rats had a two-fold decrease in oocyte count but a six-fold increase on ovarian follicular cysts, along with a higher number of total primordial and atretic follicles. Moreover, MSG rats had a four-fold increase in anti-Müllerian hormone immunohistochemical staining on antral follicles. Taken together, data presented here characterize MSG obesity as a unique model to study the metabolic pathways underlying reproductive disorders in the absence of overactivated hypothalamic-pituitary-gonadal axis. PMID:26952035

  16. Monosodium L-glutamate-induced asthma.

    PubMed

    Allen, D H; Delohery, J; Baker, G

    1987-10-01

    Ingested chemicals, including aspirin and sulfites, are becoming increasingly recognized as provokers of acute severe asthma. In order to investigate the asthma-provoking potential of the widely used flavor enhancer, monosodium L-glutamate (MSG), we challenged 32 subjects with asthma, a number of whom gave histories of severe asthma after Chinese restaurant meals or similarly spiced meals. The subjects received an additive-free diet for 5 days before challenge and were challenged in hospital, after an overnight fast, with 500 mg capsules of MSG. They were challenged in a single-blind, placebo-controlled fashion with increasing doses of MSG from 0.5 gm to 5.0 gm. 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. PMID:3312372

  17. The efficacy of probiotics for monosodium glutamate-induced obesity: dietology concerns and opportunities for prevention

    PubMed Central

    2014-01-01

    Introduction Obesity becomes endemic today. Monosodium glutamate was proved as obesogenic food additive. Probiotics are discussed to impact on obesity development. Aims and objectives The aim was to study the effects of probiotics on the development of monosodium glutamate (MSG)-induced obesity in rats. Material and methods We included 45 Wistar male rats and divided into three groups (n = 15). Newborn rats of group 1 (control) received subcutaneously 8 μl/g saline. Group 2 received 3 to 4 mg/g MSG subcutaneously on the second, fourth, sixth, eighth and tenth day of life. Within 4 months after birth, rats were on a standard diet. Group 3 received an aqueous solution of probiotics mixture (2:1:1 Lactobacillus casei IMVB-7280, Bifidobacterium animalis VKL, B. animalis VKB) at the dose of 5 × 109 CFU/kg (50 mg/kg) intragastrically. Administration of probiotics was started at the age of 4 weeks just after weaning and continued for 3 months during 2-week courses. Group 2 received intragastrically 2.5 ml/kg water. Organometric and biochemical parameters in all groups of rats were analyzed over 4 months. The concentration of adiponectin was determined in serum, and leptin - in adipose tissue. Results Administration of MSG led to the development of obesity in rats; body weight had increased by 7.9% vs controls (p < 0.05); body length had increased by 5.4% (p < 0.05). Body mass index and Lee index and visceral fat mass had increased (p < 0.001). Under the neonatal injection of MSG, the concentration of total cholesterol, triglycerides, VLDL cholesterol and LDL cholesterol significantly increased (p < 0.001), in comparison with controls. Adipose-derived hormones changed in MSG obesity rats: adiponectin decreased by 58.8% (p < 0.01), and leptin concentration in adipose tissue had increased by 74.7% (p < 0.01). The probiotic therapy of rats from group 3 prevented obesity development. Parameters of rats treated with probiotic mixture did not differ from that in

  18. Recombinant murine fibroblast growth factor 21 ameliorates obesity-related inflammation in monosodium glutamate-induced obesity rats.

    PubMed

    Wang, Wen-Fei; Li, Si-Ming; Ren, Gui-Ping; Zheng, Wei; Lu, Yu-Jia; Yu, Yin-Hang; Xu, Wen-Juan; Li, Tian-He; Zhou, Li-Hong; Liu, Yan; Li, De-Shan

    2015-05-01

    The aim of this study is to investigate the role of FGF21 in obesity-related inflammation in livers of monosodium glutamate (MSG)-induced obesity rats. The MSG rats were injected with recombinant murine fibroblast growth factor 21(FGF21) or equal volumes of vehicle. Metabolic parameters including body weight, Lee's index, food intake, visceral fat and liver weight, intraperitoneal glucose tolerance, glucose, and lipid levels were dynamically measured at specific time points. Liver function and routine blood test were also analyzed. Further, systemic inflammatory cytokines such as glucose transporter 1 (GLUT-1), leptin, TNF-α, and IL-6 mRNAs were determined by real-time PCR. FGF21 independently decreased body weight and whole-body fat mass without reducing food intake in the MSG rats. FGF21 reduced blood glucose level, Lee's index, visceral fat, and liver weight, and improved glucose tolerance, lipid metabolic spectrum, and hepatic steatosis in the MSG-obesity rats. Liver function parameters including AST, ALT, ALP, TP, T.Bili, and D.Bili levels significantly reduced in the FGF21-treated obesity rats compared to the controls. Further, FGF21 ameliorated the total and differential white blood cell (WBC) count, serum C-reactive protein (CRP), IL-6, and TNF-α levels in adipose tissues of the obesity rats, suggesting inflammation amelioration in the in the obesity rats by FGF21. FGF21 improves multiple metabolic disorders and ameliorates obesity-related inflammation in the MSG-induced obesity rats. PMID:25306889

  19. Monosodium glutamate is not likely to be genotoxic.

    PubMed

    Rogers, Michael D

    2016-08-01

    The International Glutamate Technical Committee (IGTC) wishes to comment on a recent publication in the Journal entitled "Genotoxicity of monosodium glutamate" (authored by Ataseven N, Yüzbaşıoğlu D, Keskin AÇ and Ünal F) (Ataseven et al. 2016). In particular, we wish to highlight that, in our considered view, the results of this study were inappropriately discussed and that references were selectively used. PMID:27372553

  20. Biochemical Alterations during the Obese-Aging Process in Female and Male Monosodium Glutamate (MSG)-Treated Mice

    PubMed Central

    Hernández-Bautista, René J.; Alarcón-Aguilar, Francisco J.; Escobar-Villanueva, María Del C.; Almanza-Pérez, Julio C.; Merino-Aguilar, Héctor; Konigsberg Fainstein, Mina; López-Diazguerrero, Norma E.

    2014-01-01

    Obesity, from children to the elderly, has increased in the world at an alarming rate over the past three decades, implying long-term detrimental consequences for individual’s health. Obesity and aging are known to be risk factors for metabolic disorder development, insulin resistance and inflammation, but their relationship is not fully understood. Prevention and appropriate therapies for metabolic disorders and physical disabilities in older adults have become a major public health challenge. Hence, the aim of this study was to evaluate inflammation markers, biochemical parameters and glucose homeostasis during the obese-aging process, to understand the relationship between obesity and health span during the lifetime. In order to do this, the monosodium glutamate (MSG) obesity mice model was used, and data were evaluated at 4, 8, 12, 16 and 20 months in both female and male mice. Our results showed that obesity was a major factor contributing to premature alterations in MSG-treated mice metabolism; however, at older ages, obesity effects were attenuated and MSG-mice became more similar to normal mice. At a younger age (four months old), the Lee index, triglycerides, total cholesterol, TNF-α and transaminases levels increased; while adiponectin decreased and glucose tolerance and insulin sensitivity levels were remarkably altered. However, from 16 months old-on, the Lee index and TNF-α levels diminished significantly, while adiponectin increased, and glucose and insulin homeostasis was recovered. 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. PMID:24979131

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

    PubMed

    Hernández-Bautista, René J; Alarcón-Aguilar, Francisco J; Del C Escobar-Villanueva, María; Almanza-Pérez, Julio C; Merino-Aguilar, Héctor; Fainstein, Mina Konigsberg; López-Diazguerrero, Norma E

    2014-01-01

    Obesity, from children to the elderly, has increased in the world at an alarming rate over the past three decades, implying long-term detrimental consequences for individual's health. Obesity and aging are known to be risk factors for metabolic disorder development, insulin resistance and inflammation, but their relationship is not fully understood. Prevention and appropriate therapies for metabolic disorders and physical disabilities in older adults have become a major public health challenge. Hence, the aim of this study was to evaluate inflammation markers, biochemical parameters and glucose homeostasis during the obese-aging process, to understand the relationship between obesity and health span during the lifetime. In order to do this, the monosodium glutamate (MSG) obesity mice model was used, and data were evaluated at 4, 8, 12, 16 and 20 months in both female and male mice. Our results showed that obesity was a major factor contributing to premature alterations in MSG-treated mice metabolism; however, at older ages, obesity effects were attenuated and MSG-mice became more similar to normal mice. At a younger age (four months old), the Lee index, triglycerides, total cholesterol, TNF-α and transaminases levels increased; while adiponectin decreased and glucose tolerance and insulin sensitivity levels were remarkably altered. However, from 16 months old-on, the Lee index and TNF-α levels diminished significantly, while adiponectin increased, and glucose and insulin homeostasis was recovered. 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. PMID:24979131

  2. Vagotomy ameliorates islet morphofunction and body metabolic homeostasis in MSG-obese rats.

    PubMed

    Lubaczeuski, C; Balbo, S L; Ribeiro, R A; Vettorazzi, J F; Santos-Silva, J C; Carneiro, E M; Bonfleur, M L

    2015-05-01

    The parasympathetic nervous system is important for β-cell secretion and mass regulation. Here, we characterized involvement of the vagus nerve in pancreatic β-cell morphofunctional regulation and body nutrient homeostasis in 90-day-old monosodium glutamate (MSG)-obese rats. Male newborn Wistar rats received MSG (4 g/kg body weight) or saline [control (CTL) group] during the first 5 days of life. At 30 days of age, both groups of rats were submitted to sham-surgery (CTL and MSG groups) or subdiaphragmatic vagotomy (Cvag and Mvag groups). The 90-day-old MSG rats presented obesity, hyperinsulinemia, insulin resistance, and hypertriglyceridemia. Their pancreatic islets hypersecreted insulin in response to glucose but did not increase insulin release upon carbachol (Cch) stimulus, despite a higher intracellular Ca(2+) mobilization. Furthermore, while the pancreas weight was 34% lower in MSG rats, no alteration in islet and β-cell mass was observed. However, in the MSG pancreas, increases of 51% and 55% were observed in the total islet and β-cell area/pancreas section, respectively. Also, the β-cell number per β-cell area was 19% higher in MSG rat pancreas than in CTL pancreas. Vagotomy prevented obesity, reducing 25% of body fat stores and ameliorated glucose homeostasis in Mvag rats. Mvag islets demonstrated partially reduced insulin secretion in response to 11.1 mM glucose and presented normalization of Cch-induced Ca(2+) mobilization and insulin release. All morphometric parameters were similar among Mvag and CTL rat pancreases. Therefore, the higher insulin release in MSG rats was associated with greater β-cell/islet numbers and not due to hypertrophy. Vagotomy improved whole body nutrient homeostasis and endocrine pancreatic morphofunction in Mvag rats. PMID:25714886

  3. Mechanisms underlying hypertriglyceridemia in rats with monosodium L-glutamate-induced obesity: evidence of XBP-1/PDI/MTP axis activation.

    PubMed

    França, Lucas Martins; Freitas, Larissa Nara Costa; Chagas, Vinicyus Teles; Coêlho, Caio Fernando Ferreira; Barroso, Wermerson Assunção; Costa, Graciomar Conceição; Silva, Lucilene Amorim; Debbas, Victor; Laurindo, Francisco Rafael Martins; Paes, Antonio Marcus de Andrade

    2014-01-10

    Non-alcoholic fatty liver disease (NAFLD) is intimately associated with insulin resistance and hypertriglyceridemia, whereas many of the mechanisms underlying this association are still poorly understood. In the present study, we investigated the relationship between microsomal triglyceride transfer protein (MTP) and markers of endoplasmic reticulum (ER) stress in the liver of rats subjected to neonatal monosodium L-glutamate (MSG)-induced obesity. At age 120 days old, the MSG-obese animals exhibited hyperglycemia, hypertriglyceridemia, insulin resistance, and liver steatosis, while the control (CTR) group did not. Analysis using fast protein liquid chromatography of the serum lipoproteins revealed that the triacylglycerol content of the very low-density lipoprotein (VLDL) particles was twice as high in the MSG animals compared with the CTR animals. The expression of ER stress markers, GRP76 and GRP94, was increased in the MSG rats, promoting a higher expression of X-box binding protein 1 (XBP-1), protein disulfide isomerase (PDI), and MTP. As the XBP-1/PDI/MTP axis has been suggested to represent a significant lipogenic mechanism in the liver response to ER stress, our data indicate that hypertriglyceridemia and liver steatosis occurring in the MSG rats are associated with increased MTP expression. PMID:24333444

  4. Monosodium Glutamate Intake, Dietary Patterns and Asthma in Chinese Adults

    PubMed Central

    Shi, Zumin; Yuan, Baojun; Wittert, Gary A.; Pan, Xiaoqun; Dai, Yue; Adams, Robert; Taylor, Anne W.

    2012-01-01

    Objectives Emerging evidence shows that diet is related to asthma. The aim of this analysis was to investigate the association between monosodium glutamate (MSG) intake, overall dietary patterns and asthma. Methods Data from 1486 Chinese men and women who participated in the Jiangsu Nutrition Study (JIN) were analyzed. In this study, MSG intake and dietary patterns were quantitatively assessed in 2002. Information on asthma history was collected during followed-up in 2007. Results Of the sample, 1.4% reported ever having asthma. MSG intake was not positively associated with asthma. There was a significant positive association between ‘traditional’ (high loadings on rice, wheat flour, and vegetable) food pattern and asthma. No association between ’macho’ (rich in meat and alcohol), ‘sweet tooth’ (high loadings on cake, milk, and yoghurt) ‘vegetable rich’ (high loadings on whole grain, fruit, and vegetable) food patterns and asthma was found. Smoking and overweight were not associated with asthma in the sample. Conclusion While a ‘Traditional’ food pattern was positively associated with asthma among Chinese adults, there was no significant association between MSG intake and asthma. PMID:23240044

  5. Reduction of sodium content in spicy soups using monosodium glutamate

    PubMed Central

    Jinap, Selamat; Hajeb, Parvaneh; Karim, Roslina; Norliana, Sarian; Yibadatihan, Simayi; Abdul-Kadir, Razak

    2016-01-01

    Background Excessive dietary sodium intake causes several diseases, such as hypertension, cardiovascular and renal disease, etc. Hence, reducing sodium intake has been highly recommended. In this study the effect of monosodium glutamate (MSG), as an umami substance, on saltiness and sodium reduction was investigated. Methods and Results The trained panellists were presented with basic spicy soups (curry chicken and chili chicken) containing different amounts of sodium chloride (NaCl) (0–1.2%) and MSG (0–1.2%). They tasted the optimum concentrations of NaCl and MSG for the two spicy soups and the overall acceptability were 0.8% and 0.7%, respectively. There was no significant effect of spiciness level on the saltiness and umami taste of both soups. The optimum levels of combined NaCl and MSG for overall acceptance in the chili and curry soups were 0.3% and 0.7%, respectively. The results showed that with the addition of MSG, it is possible to reduce sodium intake without changing the overall acceptability of the spicy soup. A 32.5% reduction in sodium level is made feasible by adding 0.7% MSG to the spicy soups. Conclusions This study suggests that low-sodium soups can be developed by the addition of appropriate amounts of MSG, while maintaining the acceptability of the spicy soups. It was also proven that it is feasible to reduce sodium intake by replacing NaCl with MSG. PMID:27356909

  6. Supplementing monosodium glutamate to partial enteral nutrition slows gastric emptying in preterm pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emerging evidence suggests that free glutamate may play a functional role in modulating gastroduodenal motor function. We hypothesized that supplementing monosodium glutamate (MSG) to partial enteral nutrition stimulates gastric emptying in preterm pigs. Ten-day-old preterm, parenterally fed pigs re...

  7. HPA axis and vagus nervous function are involved in impaired insulin secretion of MSG-obese rats.

    PubMed

    Miranda, Rosiane A; Torrezan, Rosana; de Oliveira, Júlio C; Barella, Luiz F; da Silva Franco, Claudinéia C; Lisboa, Patrícia C; Moura, Egberto G; Mathias, Paulo C F

    2016-07-01

    Neuroendocrine dysfunctions such as the hyperactivity of the vagus nerve and hypothalamus-pituitary-adrenal (HPA) axis greatly contribute to obesity and hyperinsulinemia; however, little is known about these dysfunctions in the pancreatic β-cells of obese individuals. We used a hypothalamic-obesity model obtained by neonatal treatment with monosodium l-glutamate (MSG) to induce obesity. To assess the role of the HPA axis and vagal tonus in the genesis of hypercorticosteronemia and hyperinsulinemia in an adult MSG-obese rat model, bilateral adrenalectomy (ADX) and subdiaphragmatic vagotomy (VAG) alone or combined surgeries (ADX-VAG) were performed. To study glucose-induced insulin secretion (GIIS) and the cholinergic insulinotropic process, pancreatic islets were incubated with different glucose concentrations with or without oxotremorine-M, a selective agonist of the M3 muscarinic acetylcholine receptor (M3AChR) subtype. Protein expression of M3AChR in pancreatic islets, corticosteronemia, and vagus nerve activity was also evaluated. Surgeries reduced 80% of the body weight gain. Fasting glucose and insulin were reduced both by ADX and ADX-VAG, whereas VAG was only associated with hyperglycemia. The serum insulin post-glucose stimulation was lower in all animals that underwent an operation. Vagal activity was decreased by 50% in ADX rats. In the highest glucose concentration, both surgeries reduced GIIS by 50%, whereas ADX-VAG decreased by 70%. Additionally, M3AChR activity was recovered by the individual surgeries. M3AChR protein expression was reduced by ADX. Both the adrenal gland and vagus nerve contribute to the hyperinsulinemia in the MSG model, although adrenal is more crucial as it appears to modulate parasympathetic activity and M3AChR expression in obesity. PMID:27113853

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

    PubMed

    Sharma, Amod

    2015-01-01

    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. PMID:26493866

  9. The role of ascorbic acid and monosodium glutamate in thymocyte apoptosis.

    PubMed

    Pavlovic, V; Sarac, M

    2010-01-01

    The studies on experimental animals have confirmed toxic effect of monosodium glutamate in different organs, mainly manifested by increased oxidative stress and cytotoxicity, strongly correlated with numerous diseases. Continuous intake of this flavor enhancer in modern nutrition also resulted with toxic effects on human health, known as Chinese restaurant syndrome. The reference data about influence of monosodium glutamate on the cells of the immune system or primary immune organs and possible protective effects of specific antioxidants are still largely unknown. This review summarizes recently known facts about the role of monosodium glutamate in the cells of the immune system, especially in thymocytes. Also, in this review many new data on positive effects of ascorbic acid on immune system and the mechanisms of its protective influence on thymocytes are discussed (Tab. 1, Ref. 52). PMID:20635684

  10. The Monosodium Glutamate Story: The Commercial Production of MSG and Other Amino Acids

    ERIC Educational Resources Information Center

    Ault, Addison

    2004-01-01

    Monosodium glutamate (MSG) is both the basis of a trillion dollar worldwide industry and a presence in the diet of a majority of the inhabitants of the world. Some parts of the "story" of MSG that might be of most interest to chemists, chemistry teachers and their students are presented.

  11. Effect of L (+) ascorbic acid and monosodium glutamate concentration on the morphology of calcium carbonate

    NASA Astrophysics Data System (ADS)

    Saraya, Mohamed El-shahte Ismaiel

    2015-11-01

    In this study, monosodium glutamate and ascorbic acid were used as crystal and growth modifiers to control the crystallization of CaCO3. Calcium carbonate prepared by reacting a mixed solution of Na2CO3 with CaCl2 at ambient temperature, (25 °C), constant Ca++/ CO3- - molar ratio and pH with stirring. The polymorph and morphology of the crystals were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The results indicate that rhombohedral calcite was only formed in water without organic additives, and both calcite and spherical vaterite with various morphologies were produced in the presence of monosodium glutamate. The content of vaterite increased as the monosodium glutamate increased. In addition, spherical vaterite was obtained in the presence of different concentrations of ascorbic acid. The spherical vaterite posses an aggregate shape composed of nano-particles, ranging from 30 to 50 nm as demonstrated by the SEM and TEM analyses. Therefore, the ascorbic stabilizes vaterite and result in nano-particles compared to monosodium glutamate.

  12. EFFECTS OF PERINATAL MONOSODIUM GLUTAMATE ADMINISTRATIONON VISUAL EVOKED POTENTIALS OF JUVENILE AND ADULT RATS

    EPA Science Inventory

    Administration of high doses of monosodium glutamate (MSG) to rats during the first postnatal week results in severe losses of retinal ganglion cells and interneurons in the retina. his study was conducted to determine what effect this severe retinal damage would have upon the on...

  13. Monosodium L-glutamate: its pharmacology and role in the Chinese restaurant syndrome.

    PubMed

    Schaumburg, H H; Byck, R; Gerstl, R; Mashman, J H

    1969-02-21

    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. PMID:5764480

  14. Prenatal monosodium glutamate (MSG) treatment given through the mother's diet causes behavioral deficits in rat offspring.

    PubMed

    Frieder, B; Grimm, V E

    1984-04-01

    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. PMID:6541212

  15. [The effect of probiotic therapy on development of experimental obesity in rats caused by monosodium glutamate].

    PubMed

    Savcheniuk, O A; Virchenko, O V; Falalieieva, T M; Beregova, T V; Babenko, L P; Lazarenko, L M; Spivak, M Ia

    2014-01-01

    The effect of a mixture of probiotic strains (2:1:1 Lactobacillus casei IMVB-7280, Bifidobacterium animalis VKL, Bifidobacterium animalis VKB) on the development of experimental obesity in rats induced by neonatal administration of monosodium glutamate has been studied. It was shown that in rats of 4 months age, the injection of monosodium glutamate (4 mg/g) at 2, 4, 6, 8, 10 days after birth elicited abdominal obesity and metabolic syndrome. An intermittent administration of a probiotic mixture to rats treated with monosodium prevented the development of obesity. In the group of rats treated with probiotics, anthropometric parameters (weight and body length, Lee index, body mass index) did not differ from the level of intact rats. Visceral fat mass was decreased by probiotics by 38.5% (P < 0.05) compared to rats treated with water. Probiotics improved lipid metabolism: reduced the level of VLDL by 32.2% (P < 0,05), the level of LDL by 30.6% (P < 0.05), increased HDL by 25.7% (P <0,05) compared to obese control rats. Probiotic strains restored the secretion of adipocytes hormones (leptin and adiponectin) to the normal level of intact animals. The results show the effectiveness of probiotics for the prevention of obesity. PMID:25007523

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

    PubMed

    Vogel, J R; Nathan, B A

    1975-01-01

    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 1-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. PMID:1208638

  17. [Oxidative stress development in the tissues of salivary glands of rats in conditions of monosodium glutamate-induced obesity].

    PubMed

    Hordiienko, L P; Berehova, T V; Neporada, K S; Falalieieva, T M

    2014-01-01

    Pathogenic mechanisms of damage of salivary glands under obesity are an insufficiently studied problem of modem medicine. On experimental model of obesity induced by monosodium glutamate, free-radical processes and antioxidant defense system were studied in the tissues of salivary glands of rats. Under experimental obesity induced by monosodium glutamate there is a significant increase of the content of thio-barbituric acid reactive substances and a significant decrease in the activity of superoxide dismutase and catalase. Thus, it indicates to the misbalance of prooxidant and antioxidant systems and the development of oxidative stress. PMID:25335241

  18. Production of a newly isolated Paenibacillus polymyxa biocontrol agent using monosodium glutamate wastewater and potato wastewater.

    PubMed

    Gu, Likun; Bai, Zhihui; Jin, Bo; Zhang, Jianyun; Li, Wenying; Zhuang, Guoqiang; Zhang, Hongxun

    2010-01-01

    A phyllosphere bacterial strain EBL-06 was isolated from wheat leaves. The morphology, cultural characteristics, phospholipid fatty acids, physiological and antagonistic fungus activities of this strain were investigated. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the relevant bacteria. The results showed that the isolate EBL-06 was a strain of Paenibacillus polymyxa; this strain performed a high level of antagonistic fungus activity toward a broad spectrum of phytopathogens, such as Botrytis cinerea, Cladosporium cucumerinum, Fusarium spp. The isolate EBL-06 can grow well using monosodium glutamate wastewater (MGW) and potato wastewater (PW) as culture medium. The maximum yield of 6.5 x 10(9) CFU/mL of the isolate EBL-06 anti-fungus biocontrol agent was reached in 15 hr cultivation at 28 degrees C, pH 6.0-7.5 using the mixture of MGW and PW (1:9). PMID:21174972

  19. Does monosodium glutamate really cause headache? : a systematic review of human studies.

    PubMed

    Obayashi, Yoko; Nagamura, Yoichi

    2016-01-01

    Although monosodium glutamate (MSG) is classified as a causative substance of headache in the International Classification of Headache Disorders 3rd edition (ICHD-III beta), there is no literature in which causal relationship between MSG and headache was comprehensively reviewed. We performed systematic review of human studies which include the incidence of headache after an oral administration of MSG. An analysis was made by separating the human studies with MSG administration with or without food, because of the significant difference of kinetics of glutamate between those conditions (Am J Clin Nutr 37:194-200, 1983; J Nutr 130:1002S-1004S, 2000) and there are some papers which report the difference of the manifestation of symptoms after MSG ingestion with or without food (Food Chem Toxicol 31:1019-1035, 1993; J Nutr 125:2891S-2906S, 1995). Of five papers including six studies with food, none showed a significant difference in the incidence of headache except for the female group in one study. Of five papers including seven studies without food, four studies showed a significant difference. Many of the studies involved administration of MSG in solution at high concentrations (>2 %). Since the distinctive MSG is readily identified at such concentrations, these studies were thought not to be properly blinded. Because of the absence of proper blinding, and the inconsistency of the findings, we conclude that further studies are required to evaluate whether or not a causal relationship exists between MSG ingestion and headache. PMID:27189588

  20. The significance of excursions above the ADI. Case study: monosodium glutamate.

    PubMed

    Walker, R

    1999-10-01

    Monosodium glutamate (MSG) has been allocated an "ADI not specified" by the JECFA, which indicates that no toxicological concerns arise associated with its use as a food additive in accordance with good manufacturing practice (GMP) and for that reason it is not necessary to allocate a numerical ADI. The question in this case, then, is not whether excursions above a numerical ADI might occur but whether high peak intakes might arise which could invalidate the assumption of absence of hazard. Two major issues have arisen in relation to high intakes of MSG: (1) What is the significance of neural damage (focal necrosis in the hypothalamus) seen following high parenteral or intragastric doses of MSG to neonatal animals and is this a particular risk for children? (2) What is the role of MSG in "Chinese Restaurant Syndrome" (flushing, tightness of the chest, difficulty in breathing, etc.) following consumption of Chinese foods? In relation to the first issue, human studies have been crucial in resolving the question. The threshold blood levels associated with neuronal damage in the mouse (most sensitive species) are 100-130 mumol/dl in neonates rising to > 630 mumol/dl in adult animals. In humans, plasma levels of this magnitude have not been recorded even after bolus doses of 150 mg/kg body wt (ca. 10 g for an adult). Additionally, studies in infants have confirmed that the human baby can metabolize glutamate as effectively as adults. It is concluded that blood levels of glutamate + aspartate do not rise significantly even after abuse doses and babies are no more at risk than adults. Intake levels associated with the use of MSG as a food additive and natural levels of glutamic acid in foods therefore do not raise toxicological concerns even at high peak levels of intake. It is not envisaged that use of MSG according to GMP requires the allocation of a numerical ADI. With regard to the second issue, controlled double-blind crossover studies have failed to establish a

  1. Monosodium glutamate in its anhydrous and monohydrate form: Differentiation by Raman spectroscopies and density functional calculations

    NASA Astrophysics Data System (ADS)

    Peica, N.; Lehene, C.; Leopold, N.; Schlücker, S.; Kiefer, W.

    2007-03-01

    Monosodium glutamate (MSG), a common flavor enhancer, is detected in aqueous solutions by Raman and surface-enhanced Raman (SERS) spectroscopies at the micromolar level. The presence of different species, such as protonated and unprotonated MSG, is demonstrated by concentration and pH dependent Raman and SERS experiments. In particular, the symmetric bending modes of the amino group and the stretching modes of the carboxy moiety are employed as marker bands. The protonation of the NH 2 group at acidic pH values, for example, is detected in the Raman spectra. From the measured SERS spectra, a strong chemical interaction of MSG with the colloidal particles is deduced and a geometry of MSG adsorbed on the silver surface is proposed. In order to assign the observed Raman bands, calculations employing density functional theory (DFT) were performed. The calculated geometries, harmonic vibrational wavenumbers and Raman scattering activities for both MSG forms are in good agreement with experimental data. The set of theoretical data enables a complete vibrational assignment of the experimentally detected Raman spectra and the differentiation between the anhydrous and monohydrate forms of MSG.

  2. Neonatal exposure to monosodium glutamate induces morphological alterations in suprachiasmatic nucleus of adult rat.

    PubMed

    Rojas-Castañeda, Julio César; Vigueras-Villaseñor, Rosa María; Chávez-Saldaña, Margarita; Rojas, Patricia; Gutiérrez-Pérez, Oscar; Rojas, Carolina; Arteaga-Silva, Marcela

    2016-02-01

    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. PMID:26799547

  3. Monosodium glutamate derived tricolor fluorescent carbon nanoparticles for cell-imaging application.

    PubMed

    Zheng, Nannan; Ding, Sha; Zhou, Xingping

    2016-06-01

    Fluorescent carbon nanoparticle (FCN) is a new type of carbon-based materials. Because of its wide raw material sources, excellent optical properties and good biocompatibility, FCN is getting more and more attentions. However, its synthesis from resources at low cost under mild conditions is still a challenge. Here we report a novel and simple method derived from monosodium glutamate carbonization to make tricolor fluorescent carbon nanoparticles with an average size below 10nm, a high yield up to 35.2% based on the carbon content in the resource, a long life-time of 3.71ns, and a high fluorescence quantum yield up to 51.5% by using quinine sulfate as the standard substance. We discovered that the fluorescent stability of the FCNs was very excellent under UV irradiation for hours in aqueous solutions of pH ranged from 2.0 to 9.0. The cell viability tested under a pretty high concentration of FCNs indicated their safety for biological applications. Based on their high fluorescence quantum efficiency and the advantages mentioned above, these FCNs were then used for cell imaging and exhibited a perfect performance under 3 kinds of excitation bands (UV, blue, and green lights). Thus, they can be practically applied to immune labeling and imaging in vivo in the near future. PMID:26945164

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

    PubMed

    Park, Ji-Hun; Choi, Tae-Saeng

    2016-04-01

    Administering monosodium glutamate (MSG) to neonatal rodents induces obesity and type 2 diabetes. In addition, several studies have shown that MSG administered to pregnant animals can cross the placenta and reach the foetus. The present study was performed to investigate the effects of administering MSG to pregnant ICR mice on dam and neonatal growth. Pregnant mice were treated with 60 or 120 mg MSG once daily from day 5 of pregnancy to one day before parturition by subcutaneous injection. In addition, the body weights of the neonates were determined until nine weeks of age. The birth weights of neonates were not different between the control and MSG-treated groups. However, MSG treatment resulted in a lower body weight gain of neonates during lactation. In addition, this underweight of the MSG-treated group at weaning returned to normal compared with the control group at five weeks of age. Cross-fostering experiments indicated that the lower body weight gain of neonates in the MSG-treated group during lactation was due to its effects on the dam. Serum prolactin levels and mammary gland development of the mice were examined next to determine the reasons for this lactation problem. 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. PMID:26043886

  5. Monosodium L-glutamate: a double-blind study and review.

    PubMed

    Tarasoff, L; Kelly, M F

    1993-12-01

    71 healthy subjects were treated with placebos and monosodium L-glutamate (MSG) doses of 1.5, 3.0 and 3.15 g/person, which represented a body mass-adjusted dose range of 0.015-0.07 g/kg body weight before a standardized breakfast over 5 days. The study used a rigorous randomized double-blind crossover design that controlled for subjects who had MSG after-tastes. Capsules and specially formulated drinks were used as vehicles for placebo and MSG treatments. Subjects mostly had no responses to placebo (86%) and MSG (85%) treatments. Sensations, previously attributed to MSG, did not occur at a significantly higher rate than did those elicited by placebo treatment. A significant (P < 0.05) negative correlation between MSG dose and after-effects was found. The profound effect of food in negating the effects of large MSG doses was demonstrated. The common practice of extrapolating food-free experimental results to 'in use' situations was called into question. An exhaustive review of previous methodologies identified the strong taste of MSG as the factor invalidating most 'blind' and 'double-blind' claims by previous researchers. The present study led to the conclusion that 'Chinese Restaurant Syndrome' is an anecdote applied to a variety of postprandial illnesses; rigorous and realistic scientific evidence linking the syndrome to MSG could not be found. PMID:8282275

  6. Protective effects of N-acetylcysteine against monosodium glutamate-induced astrocytic cell death.

    PubMed

    Park, Euteum; Yu, Kyoung Hwan; Kim, Do Kyung; Kim, Seung; Sapkota, Kumar; Kim, Sung-Jun; Kim, Chun Sung; Chun, Hong Sung

    2014-05-01

    Monosodium glutamate (MSG) is a flavor enhancer, largely used in the food industry and it was reported to have excitotoxic effects. Higher amounts of MSG consumption have been related with increased risk of many diseases, including Chinese restaurant syndrome and metabolic syndromes in human. This study investigated the protective effects of N-acetylcysteine (NAC) on MSG-induced cytotoxicity in C6 astrocytic cells. MSG (20 mM)-induced reactive oxygen species (ROS) generation and apoptotic cell death were significantly attenuated by NAC (500 μM) pretreatment. NAC effectively inhibited the MSG-induced mitochondrial membrane potential (MMP) loss and intracellular reduced glutathione (GSH) depletion. In addition, NAC significantly attenuated MSG-induced endoplasmic reticulum (ER) stress markers, such as XBP1 splicing and CHOP, PERK, and GRP78 up-regulation. Furthermore, NAC prevented the changes of MSG-induced Bcl-2 expression level. These results suggest that NAC can protect C6 astrocytic cells against MSG-induced oxidative stress, mitochondrial dysfunction, and ER stress. PMID:24556569

  7. [Characterization of an experimental model of monosodium- glutamate-induced convulsions in the amphibian Bufo spp].

    PubMed

    Alfaro, F; Blas, O; Gutiérrez-Padilla, R; Feria-Velasco, A

    1990-01-01

    In previous reports, Feria-Velasco et al. characterized an experimental model of convulsions in rats induced by monosodium glutamate (MSG) with evaluation of the motor behavior and neurochemical parameters. In the present work, MSG injected in toads (Bufo spp) reproduced the model of convulsions with some peculiarities. The electrocorticographic recordings in toads after MSG injection were similar to those obtained in rats after administration of convulsant agents. Most of the toads injected with MSG (81.8%) showed convulsions preceded by an episode of stereotyped movements and signs of hyperexcitability. Latency for convulsions and frequency of convulsive episodes were similar to what has been reported in rats injected with MSG. However, the duration of convulsive period was larger than that seen in rats, and no deaths were recorded in toads. The peculiar feature of amphibia regarding their cerebral structures and their blood-brain barrier (BBB) make the amphibian model, an interesting and valuable one in studying experimentally induced convulsions, as well as the role of BBB in these phenomena. PMID:1669233

  8. Monosodium glutamate-sensitive hypothalamic neurons contribute to the control of bone mass

    NASA Technical Reports Server (NTRS)

    Elefteriou, Florent; Takeda, Shu; Liu, Xiuyun; Armstrong, Dawna; Karsenty, Gerard

    2003-01-01

    Using chemical lesioning we previously identified hypothalamic neurons that are required for leptin antiosteogenic function. In the course of these studies we observed that destruction of neurons sensitive to monosodium glutamate (MSG) in arcuate nuclei did not affect bone mass. However MSG treatment leads to hypogonadism, a condition inducing bone loss. Therefore the normal bone mass of MSG-treated mice suggested that MSG-sensitive neurons may be implicated in the control of bone mass. To test this hypothesis we assessed bone resorption and bone formation parameters in MSG-treated mice. We show here that MSG-treated mice display the expected increase in bone resorption and that their normal bone mass is due to a concomitant increase in bone formation. Correction of MSG-induced hypogonadism by physiological doses of estradiol corrected the abnormal bone resorptive activity in MSG-treated mice and uncovered their high bone mass phenotype. Because neuropeptide Y (NPY) is highly expressed in MSG-sensitive neurons we tested whether NPY regulates bone formation. Surprisingly, NPY-deficient mice had a normal bone mass. 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.

  9. Metabolomic profiling of urinary changes in mice with monosodium glutamate-induced obesity.

    PubMed

    Pelantová, Helena; Bártová, Simona; Anýž, Jiří; Holubová, Martina; Železná, Blanka; Maletínská, Lenka; Novák, Daniel; Lacinová, Zdena; Šulc, Miroslav; Haluzík, Martin; Kuzma, Marek

    2016-01-01

    Obesity with related complications represents a widespread health problem. The etiopathogenesis of obesity is often studied using numerous rodent models. The mouse model of monosodium glutamate (MSG)-induced obesity was exploited as a model of obesity combined with insulin resistance. The aim of this work was to characterize the metabolic status of MSG mice by NMR-based metabolomics in combination with relevant biochemical and hormonal parameters. NMR analysis of urine at 2, 6, and 9 months revealed altered metabolism of nicotinamide and polyamines, attenuated excretion of major urinary proteins, increased levels of phenylacetylglycine and allantoin, and decreased concentrations of methylamine in urine of MSG-treated mice. Altered levels of creatine, citrate, succinate, and acetate were observed at 2 months of age and approached the values of control mice with aging. The development of obesity and insulin resistance in 6-month-old MSG mice was also accompanied by decreased mRNA expressions of adiponectin, lipogenetic and lipolytic enzymes and peroxisome proliferator-activated receptor-gamma in fat while mRNA expressions of lipogenetic enzymes in the liver were enhanced. At the age of 9 months, biochemical parameters of MSG mice were normalized to the values of the controls. This fact pointed to a limited predictive value of biochemical data up to age of 6 months as NMR metabolomics confirmed altered urine metabolic composition even at 9 months. PMID:26577083

  10. Condensation of supersaturated water vapor on charged/neutral nanoparticles of glucose and monosodium glutamate.

    PubMed

    Chen, Chin-Cheng; Tao, Chun-Ju; Cheng, Hsiu-Chin

    2002-11-01

    The effects of size, charge, dissolution, and dissociation on the condensation of supersaturated water vapor on monodisperse nanoparticles of glucose and monosodium glutamate (MSG) were investigated in a flow cloud chamber (FCC). The dependence of the critical supersaturation, S(cr), on particle size in the range of 30 to 90 nm and on temperature in the range of 10 to 50 degrees C were determined experimentally. The results show that the experimental S(cr) decreases with increasing particle size at a rate in reasonable agreement with the predictions of the Kohler and Volmer theories of nucleation for soluble particles, but decreases with increasing temperature at a rate higher than the prediction of the Volmer theory. The dissociation of MSG into ions lowers the experimental S(cr) to a value smaller than that for the more soluble glucose, agreeing with predictions. The experimental S(cr) is smaller than the predictions of both theories, and the discrepancy cannot be fully explained by the reductions in surface tension due to the dissolution of particles and curvature dependence. The condensation of supersaturated vapor on singly positively charged particles with diameters of 30, 60, and 90 nm was also examined, and no obvious charge effect on S(cr) was observed. PMID:12702381

  11. Adjusting irradiance to enhance growth and lipid production of Chlorella vulgaris cultivated with monosodium glutamate wastewater.

    PubMed

    Jiang, Liqun; Ji, Yan; Hu, Wenrong; Pei, Haiyan; Nie, Changliang; Ma, Guixia; Song, Mingming

    2016-09-01

    Light is one of the most important factors affecting microalgae growth and biochemical composition. The influence of illumination on Chlorella vulgaris cultivated with diluted monosodium glutamate wastewater (MSGW) was investigated. Six progressive illumination intensities (0, 30, 90, 150, 200 and 300μmol·m(-2)s(-1)), were used for C. vulgaris cultivation at 25°C. Under 150μmol·m(-2)s(-1), the corresponding specific light intensity of 750×10(-6)μmol·m(-2)s(-1) per cell, algae obtained the maximum biomass concentration (1.46g·L(-1)) on the 7th day, which was 3.5 times of that under 0μmol·m(-2)s(-1), and the greatest average specific growth rate (0.79 d(-1)) in the first 7days. The results showed the importance role of light in mixotrophic growth of C. vulgaris. High light intensities of 200 and 300μmol·m(-2)s(-1) would inhibit microalgae growth to a certain degree. The algal lipid content was the greatest (30.5%) at 150μmol·m(-2)s(-1) light intensity, which was 2.42 times as high as that cultured in dark. The protein content of C. vulgaris decreased at high light intensities of 200 and 300μmol·m(-2)s(-1). The effect of irradiance on carbohydrate content was inversely correlated with that on protein. The available light at an appropriate intensity, not higher than 200μmol·m(-2)s(-1), was feasible for economical cultivation of C. vulgaris in MSGW. PMID:27484967

  12. Intragastric monosodium L-glutamate stimulates motility of upper gut via vagus nerve in conscious dogs.

    PubMed

    Toyomasu, Yoshitaka; Mochiki, Erito; Yanai, Mitsuhiro; Ogata, Kyoichi; Tabe, Yuichi; Ando, Hiroyuki; Ohno, Tetsuro; Aihara, Ryuusuke; Zai, Hiroaki; Kuwano, Hiroyuki

    2010-04-01

    Monosodium l-glutamate (MSG) is a substance known to produce the umami taste. Recent studies indicate that MSG also stimulates a variety of activities in the gastrointestinal tract through its receptor in the gut, but no study has reported the activity in conscious large experimental animals. The aim of our study was to investigate whether direct intragastric MSG stimulates gut motility and to identify the mechanism in conscious dogs. Contractile response to intraluminal injection of MSG was studied in the fed and fasted states by means of chronically implanted force transducers. MSG (5, 15, 45, and 90 mM/kg) dissolved in water was injected into the stomach and duodenum in normal and vagotomized dogs. MSG solution was administered into the stomach before feeding, and gastric emptying was evaluated. Several inhibitors of gastrointestinal motility (atropine, hexamethonium, and granisetron) were injected intravenously before MSG administration to the stomach. The effect of MSG was investigated in Pavlov (vagally innervated corpus pouch), Heidenhain (vagally denervated corpus pouch), and antral pouch (vagally innervated) dogs. Upper gut motility was significantly increased by intragastric MSG but not significantly stimulated by intraduodenal MSG. Intragastric MSG (45 mM/kg) stimulated postprandial motility and accelerated gastric emptying. MSG-induced contractions were inhibited by truncal vagotomy, atropine, hexamethonium, and granisetron. Gut motility was increased by intrapouch injection of MSG in the Pavlov pouch, but it was not affected in the Heidenhain or antral pouch dogs. We conclude that intragastric MSG stimulates upper gut motility and accelerates gastric emptying. The sensory structure of MSG is present in the gastric corpus, and the signal is mediated by the vagus nerve. PMID:20071606

  13. Effects of bezafibrate in nonalcoholic steatohepatitis model mice with monosodium glutamate-induced metabolic syndrome.

    PubMed

    Sasaki, Yoshiyuki; Shimada, Tsutomu; Iizuka, Seiichi; Suzuki, Wataru; Makihara, Hiroko; Teraoka, Ryutaro; Tsuneyama, Koichi; Hokao, Ryoji; Aburada, Masaki

    2011-07-15

    Recently, we reported that monosodium glutamate-treated mice (MSG mice) developed severe hyperlipidemia and diabetes mellitus and several complications of obesity. MSG mice acquired fatty livers and subsequently underwent changes that are characteristic of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). In the present study, the effects of bezafibrate on obesity, diabetes mellitus, and NAFLD/NASH were examined in MSG mice. A single dose of MSG (4 mg/g) was administered subcutaneously to neonatal male mice within 24h of birth. Bezafibrate was mixed into the normal feed for 8 weeks. The weight and body mass index of MSG mice increased significantly despite the unchanged intake of food. Triglyceride and total cholesterol levels in blood, visceral adipose tissue, and interscapular adipose tissue rose significantly. In the livers of MSG mice, moderate centrilobular microvesicular steatosis, ballooning degeneration with Mallory bodies, and scattered infiltration of neutrophils and lymphocytes were observed. Centrilobular hepatocytes were 4-hydroxynonenal-positive in MSG mice. Bezafibrate ameliorated the severity of diabetes mellitus, hyperinsulinemia, and hyperlipidemia. Adiponectin and leptin concentrations in blood improved, and the accumulation of visceral fat was inhibited. The expression of acyl-CoA oxidase, a beta-oxidation gene, and carnitine palmitoyl transferase, which regulates lipid metabolism, increased markedly on administration of bezafibrate. The liver pathology in MSG mice also improved with bezafibrate; specifically, macro- and microvesicles in hepatocytes nearly disappeared, and NAFLD activity score improved. It is concluded that bezafibrate inhibits the accumulation of visceral fat, following amelioration of hyperlipidemia, in MSG-induced obese mice, due to improvements in diabetes mellitus, fatty liver, and NAFLD. PMID:21549692

  14. Drug-metabolizing and antioxidant enzymes in monosodium L-glutamate obese mice.

    PubMed

    Matoušková, Petra; Bártíková, Hana; Boušová, Iva; Levorová, Lucie; Szotáková, Barbora; Skálová, Lenka

    2015-02-01

    The prevalence of obesity is rapidly increasing across the world. Physiologic alterations associated with obesity are known to alter enzyme expression and/or activities. As drug-metabolizing and antioxidant enzymes serve as defense system against potentially toxic compounds, their modulation might have serious consequences. In this work, we studied selected antioxidant and drug-metabolizing enzymes (DME) in monosodium glutamate-mouse model of obesity. Specific activities, protein, and mRNA expressions of these enzymes in liver as well as in small intestine were compared in obese male mice and in their lean counterparts. Furthermore, expression of the NF-E2-related factor 2 (Nrf2) and its relation to obesity were tested. Obtained results showed that obesity affects expression and/or activities of some DME and antioxidant enzymes. In obese mice, upregulation of UDP-glucuronosyltransferases 1A (UGT1A), NAD(P)H:quinone oxidoreductase 1 (NQO1), nuclear transcription factor Nrf2, and downregulation of some isoforms of glutathione S-transferases (GST) were observed. Most of these changes were tissue and/or isoform specific. NQO1 seems to be regulated transcriptionally via Nrf2, but other enzymes might be regulated post-transcriptionally and/or post-translationally. Enhanced expression of Nrf2 in livers of obese mice is expected to play a role in protective adaptation. 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. PMID:25473020

  15. Monosodium Glutamate Dietary Consumption Decreases Pancreatic β-Cell Mass in Adult Wistar Rats

    PubMed Central

    Boonnate, Piyanard; Waraasawapati, Sakda; Hipkaeo, Wiphawi; Pethlert, Supattra; Sharma, Amod; Selmi, Carlo; Prasongwattana, Vitoon; Cha’on, Ubon

    2015-01-01

    Background The amount of dietary monosodium glutamate (MSG) is increasing worldwide, in parallel with the epidemics of metabolic syndrome. Parenteral administration of MSG to rodents induces obesity, hyperglycemia, hyperlipidemia, insulin resistance, and type 2 diabetes. However, the impact of dietary MSG is still being debated. We investigated the morphological and functional effects of prolonged MSG consumption on rat glucose metabolism and on pancreatic islet histology. Methods Eighty adult male Wistar rats were randomly subdivided into 4 groups, and test rats in each group were supplemented with MSG for a different duration (1, 3, 6, or 9 months, n=20 for each group). All rats were fed ad libitum with a standard rat chow and water. Ten test rats in each group were provided MSG 2 mg/g body weight/day in drinking water and the 10 remaining rats in each group served as non-MSG treated controls. Oral glucose tolerance tests (OGTT) were performed and serum insulin measured at 9 months. Animals were sacrificed at 1, 3, 6, or 9 months to examine the histopathology of pancreatic islets. Results MSG-treated rats had significantly lower pancreatic β-cell mass at 1, 6 and 9 months of study. Islet hemorrhages increased with age in all groups and fibrosis was significantly more frequent in MSG-treated rats at 1 and 3 months. Serum insulin levels and glucose tolerance in MSG-treated and untreated rats were similar at all time points we investigated. 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. PMID:26121281

  16. Effects of CB1 receptor blockade on monosodium glutamate induced hypometabolic and hypothalamic obesity in rats.

    PubMed

    Chen, Wei; Chen, Zhenhua; Xue, Nina; Zheng, Zhibing; Li, Song; Wang, Lili

    2013-08-01

    Effects of cannabinoid receptor 1 (CB1R) blockade were observed by comparing 9-day and 6-week SR141716 treatments in monosodium glutamate (MSG)-induced hypometabolic and hypothalamic obesity (HO) in rats for the first time and molecular mechanisms were investigated. Compared with normal rats, the MSG rats display typical symptoms of the metabolic syndrome, i.e., excessive abdominal obesity, hypertriglyceridemia, hyperinsulinemia, insulin resistance, and hepatic steatosis, but with lower food intake. Although both the 9-day and 6-week treatments with the specific CB1R antagonist SR141716 effectively lowered body weight, intraperitoneal adipose tissue mass, serum triglyceride (TG), and insulin level, the effect of chronic treatment is more impressive. Moreover, serum cholesterol, free fatty acids (FFA), fasted and postprandial blood glucose, and insulin insensitivity were more effectively improved by 6-week exposure to SR141716, whereas hypophagia was only effective within the initial 2 weeks. In addition, hepatic steatosis as well as hepatic and adipocyte morphology was improved. Western blot analysis revealed that the markedly increased CB1R expression and decreased insulin receptor (INR) expression in liver and adipose tissues were effectively corrected by SR141716. Consistent with this, deregulated gene expression of lipogenesis and lipolysis as well as glucose metabolic key enzymes were also restored by SR141716. In conclusion, based on present data we found that: (1) alteration of the hypothalamus in MSG rats leads to a lower expression of INR in crucially insulin-targeted tissues and hyperinsulinemia that was reversed by SR141716, (2) the abnormally increased expression of CB1R in liver and adipose tissues plays a vital role in the pathophysiological process of MSG rats, and (3) chronic CB1R blockade leads to a sustained improvement of the metabolic dysfunctions of MSG rats. PMID:23620336

  17. [Pathological changes in hepatocytes of mice with obesity-induced type 2 diabetes by monosodium glutamate].

    PubMed

    Nakadate, Kazuhiko; Motojima, Kento; Kamata, Sumito; Yoshida, Testuro; Hikita, Masaaki; Wakamatsu, Hisanori

    2014-01-01

    Type 2 diabetes caused by chronic obesity is a major lifestyle-related disease. The present study aimed to determine the pathological changes in hepatocytes in chronic obesity. To develop our type 2 diabetes mouse model, we induced chronic obesity to mice by monosodium glutamate. By overeating, the mice significantly increased their body weight compared with age-matched healthy animals. To analyze the pathological changes in hepatocytes of chronic obesity before preclinical stage of type 2 diabetes, the mice were analyzed by hematoxylin-eosin staining of tissue sections at 15 w of age. In these mice, we observed eosin-negative accumulations of hepatocytes around central veins in the hepatic lobule. By Oil-Red O staining, the eosin-negative granules were identified in the lipid droplets. We then ascertained whether these lipid droplets of hepatocytes in the obese mice could be modified by diet. After 24 h of diet restriction, the lipid droplets of hepatocytes in the obese mice were swollen. Furthermore, after 48 h of the diet restriction, the lipid droplets continued swelling and the autophagy-like structures that were found in the healthy mice under the same condition in the obese mice were not observed. 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. PMID:24989474

  18. GLUT4 protein is differently modulated during development of obesity in monosodium glutamate-treated mice.

    PubMed

    de Carvalho Papa, Paula; Vargas, Alessandra Martins; da Silva, José Luciano Tavares; Nunes, Maria Tereza; Machado, Ubiratan F

    2002-09-01

    The aim of the present study was to investigate the GLUT4 protein expression during the development of obesity in monosodium glutamate- (MSG) treated mice. Control (C) and neonatally MSG-treated 2-month-old (2-mo), 4-month-old (4-mo) and 7-month-old (7-mo) mice were analyzed. Anthropometric data, basal glycemia and insulinemia were measured; and the GLUT4 protein was assessed by Western blotting in white adipose tissue (WAT), skeletal muscle gastrocnemius (SM) and heart (H). Compared to age-matched C mice, the 2-mo and 4-mo MSG mice were already obese, but metabolically they showed increased or preserved whole-body insulin sensitivity, respectively. At these ages they showed unchanged total GLUT4 content in SM and H. However, in plasma membrane fraction from WAT, the MSG showed increased GLUT4 content at both 2- (by 60%) and 4-month (by 45%) of age. When the GLUT4 protein was expressed by unit of adipocyte surface area the protein amount was increased by 36 and 220% in 2-mo and 4-mo MSG mice, respectively. At 7 months of age, obesity was fully established in MSG mice, showing a strongly insulin resistant condition. Additionally, in the 7-mo MSG-mice the GLUT4 protein was reduced in SM (by 40%), H (by 28%), PM and M fractions of WAT (by approximately 70%), and PM expressed by unit of adipocyte surface area (by 92%). The data demonstrate that early, during the accelerated development of obesity in MSG-treated mice, the GLUT4 content was increased in WAT, and that may play a key role in the development of obesity. Later on, when obesity is fully established, the GLUT4 protein was reduced in SM, heart and WAT, and that may be involved in the insulin resistance present in this condition. PMID:12175706

  19. Chronobiological variations in the convulsive effect of monosodium L-glutamate when administered to adult rats.

    PubMed

    Feria-Velasco, A; Feria-Cuevas, Y; Gutiérrez-Padilla, R

    1995-01-01

    Monosodium L-glutamate (MSG) when administered intraperitoneally (i.p.) to rodents induces convulsions and has been used as a model to study various aspects of status epilepticus of multifocal origin. There are circadian variations of susceptibility to convulsions induced by various factors in some animal species. The aim of this work was to learn whether the convulsive effect of MSG in rats would vary when the drug is given at different times of the day. Three subgroups of Wistar rats were given i.p. 5 mg/g MSG at 07:00, 15:00 and 23:00 h, whereas two groups of rats divided into three subgroups of five animals each were used as controls, also being injected at 07:00, 15:00 and 23:00 h. One group was injected with NaCI solution, equimolar to that of MSG (eqNaCI); the other was injected with physiological saline solution (PSS) in proportional volumes to those of the experimental group. Motor behavior was recorded for 4 h following injections in the three groups of animals. Neither signs of brain hyperexcitability, nor convulsions appeared in animals injected with PSS or eqNaCl. With MSG, no variations were seen in the latency period when data from the three subgroups studied were compared among them. Duration of convulsive period when rats were injected at 07:00 h was shorter than that seen at 15:00 and 23:00 h. No significant variations were seen in total number of convulsive episodes in the three subgroups, while the number of seizures per hour and their intensity were significantly greater when animals were injected at 07:00 h than those seen when rats were studied at 15:00 and 23:00 h. Nearly 70% of animals injected at 07:00 h died in status epilepticus, whereas no deaths were recorded in animals injected at 15:00 and 23:00 h. Results could be explained in terms of variations of physiological processes at both the brain and extracerebral tissues involved in MSG metabolism and cerebral excitability, related to circadian rhythms. PMID:8845636

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

    PubMed

    Krawczyk, A; Jaworska-Adamu, J; Rycerz, K

    2015-01-01

    High concentration of glutamate (Glu) is excitotoxic for nervous system structures. This may lead to glial reactivity ie. increased expression of glial fibrillary acidic protein (GFAP) and S100β protein, and also to hypertrophy and proliferation of cells which are determined by the presence of Ki-67 antigen. The aim of the study was to analyse the immunoreactivity of the GFAP, S100β and Ki-67 proteins in astrocytes of hippocampal CA1 region in young rats after administration of monosodium glutamate (MSG) at two doses: 2 g/kg b.w. (I group) and 4 g/kg b.w. (II group). In rats from I and II group morphologically altered astrocytes with the GFAP expression were observed in the SLM of the hippocampal CA1 region. The cells had eccentrically located nuclei and on the opposite site of the nuclei there were single or double, long and weakly branched processes. Moreover, in the SLM the increase of the number of GFAP and S100β immunopositive astrocytes and nuclei with Ki-67 expression, in contrary to control individuals, was observed. 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. PMID:26812818

  1. The feasibility of using complex wastewater from a monosodium glutamate factory to cultivate Spirulina subsalsa and accumulate biochemical composition.

    PubMed

    Jiang, Liqun; Pei, Haiyan; Hu, Wenrong; Ji, Yan; Han, Lin; Ma, Guixia

    2015-03-01

    This paper is mainly observations on the growth and biomass accumulation of Spirulina subsalsa in modified Zarrouk medium supplemented with complex wastewater (CW, from a monosodium glutamate factory) in different concentrations. High ammonia in 75% and 100% CW inhibits algae growth, but maximum biomass production (2.86mgL(-1)) was obtained in 25% CW (concentration of CW in medium was 25%). Different CW concentration promoted biomass composition accumulation at different degrees, 41% of protein content in 25% CW and 18% of carbohydrate in 50% CW. In terms of economy, a concentration of 25% CW was suitable for protein production and 50% for lipid and carbohydrate production. These results suggested that CW is a feasible replacement in part for cultivation of S. subsalsa to economize input of water and nutrients. PMID:25621725

  2. Monosodium glutamate-induced asthma: study of the potential risk of 30 asthmatics and review of the literature.

    PubMed

    Moneret-Vautrin, D A

    1987-01-01

    Monosodium glutamate is a physiological nutrient, and food additive used as a taste enhancer. Several cases of intolerance to MSG in patients with asthma and with a Chinese Restaurant Syndrome have been published. A high dose of 2.5 g was tested in 6 healthy controls and 30 asthmatics (7: allergic asthma; 15: intrinsic asthma with intolerance to aspirin; 8: intrinsic asthma with aspirin intolerance, intolerance to alcohol or to food additives). Two patients presented with a mild bronchospasm, occurring 6 to 10 hours after the ingestion. Different mechanisms are discussed. A cholinergic mechanism might be incriminated, either due to stimulation of the synthesis of acetylcholine, or due to a vagal reflex elicited by a reflux esophagitis. However, a high vagal hyperreactivity seems to be needed for the occurrence of asthma. It is concluded that a very small subset of patients with intrinsic asthma might present with an intolerance to MSG if high doses are consumed. PMID:3331265

  3. No effects of monosodium glutamate consumption on the body weight or composition of adult rats and mice.

    PubMed

    Tordoff, Michael G; Aleman, Tiffany R; Murphy, Michelle C

    2012-10-10

    Monosodium glutamate (MSG) is pervasively consumed as a flavor enhancer so there are important implications to understanding its physiological actions, particularly its effects on body weight. Previous studies suggest that MSG increases, decreases, or has no effect on the body weight of rodents. However, most of these studies involved administration of MSG to immature rodents and consequently may not be relevant for understanding human obesity. We report here five experiments in which we measured the body weights of a total of 32 groups of 10-12 adult rats or mice given various diets to eat and MSG to eat or drink. We found no evidence that MSG influenced body weight, energy intake, or body composition. To the extent that experiments in rodents illuminate mechanisms involved in human obesity and body weight control, our results suggest that MSG is unlikely to be a useful anti-obesity supplement but neither is it responsible for exacerbating obesity. PMID:22868067

  4. Swim training of monosodium L-glutamate-obese mice improves the impaired insulin receptor tyrosine phosphorylation in pancreatic islets.

    PubMed

    Miranda, Rosiane Aparecida; Branco, Renato Chaves Souto; Gravena, Clarice; Barella, Luiz Felipe; da Silva Franco, Claudinéia Conationi; Andreazzi, Ana Eliza; de Oliveira, Júlio Cezar; Picinato, Maria Cecília; de Freitas Mathias, Paulo Cezar

    2013-06-01

    The goal of the present study was to investigate changes on glucose homoeostasis and of the insulin receptor (IR) and insulin receptor substrate-1 (IRS-1) signalling in pancreatic islets from MSG-obese mice submitted to or not submitted to swim training. Swim training of 90-day-old MSG mice was used to evaluate whether signalling pathways of the IR and IRS-1 in islets are involved with the insulin resistance and glucose intolerance observed in this obese animal model. The results showed that IR tyrosine phosphorylation (pIR) was reduced by 42 % in MSG-obese mice (MSG, 6.7 ± 0.2 arbitrary units (a.u.); control, 11.5 ± 0.4 a.u.); on the other hand, exercise training increased pIR by 76 % in MSG mice without affecting control mice (MSG, 11.8 ± 0.3; control, 12.8 ± 0.2 a.u.). Although the treatment with MSG increased IRS-1 tyrosine phosphorylation (pIRS-1) by 96 % (MSG, 17.02 ± 0.6; control, 8.7 ± 0.2 a.u.), exercise training also increased it in both groups (control, 13.6 ± 0.1; MSG, 22.2 ± 1.1 a.u.). Current research shows that the practice of swim training increases the tyrosine phosphorylation of IRS-1 which can modulate the effect caused by obesity in insulin receptors. PMID:22983867

  5. Monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine improve the sensory quality of fermented cooked sausages with 50% and 75% replacement of NaCl with KCl.

    PubMed

    dos Santos, Bibiana Alves; Campagnol, Paulo Cezar Bastianello; Morgano, Marcelo Antônio; Pollonio, Marise Aparecida Rodrigues

    2014-01-01

    Fermented cooked sausages were produced by replacing 50% and 75% of NaCl with KCl and adding monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine. The manufacturing process was monitored by pH and water activity measurements. The sodium and potassium contents of the resulting products were measured. The color values (L*, a* and b*), texture profiles and sensory profiles were also examined. Replacing 50% and 75% NaCl with KCl depreciated the sensory quality of the products. The reformulated sausages containing monosodium glutamate combined with lysine, taurine, disodium inosinate and disodium guanylate masked the undesirable sensory attributes associated with the replacement of 50% and 75% NaCl with KCl, allowing the production of fermented cooked sausages with good sensory acceptance and approximately 68% sodium reduction. PMID:24008059

  6. Gastric emptying and duodenal motility upon intake of a liquid meal with monosodium glutamate in healthy subjects

    PubMed Central

    Teramoto, Hidemi; Shimizu, Toshiyasu; Yogo, Hideto; Nishimiya, Yuuta; Hori, Shinji; Kosugi, Takashi; Nakayama, Shinsuke

    2014-01-01

    Abstract Glutamate is thought to serve as a special signal for gut functions. We investigated the effects of monosodium l‐glutamate (MSG) on gastric emptying and duodenal motility. Ten healthy male volunteers underwent rapid magnetic resonance imaging (MRI) of the abdomen. Coronal images were successively acquired after ingestion of liquid meal (200 kcal in 200 mL: 9 g protein, 28.4 g carbohydrate, 5.6 g fat, 370 mg Na+) with and without 0.5% MSG. During the acquisition of MRI, participants breathed freely. In all participants, the gastric residual volume gradually decreased to 80.1 ± 14.2% without MSG and to 75.9 ± 14.3% with MSG after 60 min (P = 0.45 between the groups, n = 10). In two of 10 participants, gastric emptying slowed down significantly, whereas in the remaining eight participants, gastric residual volume decreased to 84.0 ± 13.1% without MSG, and to 73.0 ± 14.6% with MSG after 60 min (P = 0.015, n = 8). There was no difference in the shape of the stomach between groups. In four of the eight participants responding positively to MSG, the duodenum wall was sufficiently identified to quantify the motions. The inclusion of MSG enhanced duodenal motility, judging from changes in (1) the magnitude of the duodenal area, (2) the center of gravity, and (3) the mean velocity of the wall motions. The third parameter most significantly indicated the excitatory effect of l‐glutamate on duodenum motility (~ three‐ to sevenfold increase during 60 min, P < 0.05, n = 4). These results suggest that MSG accelerates gastric emptying by facilitating duodenal motility, at least in subjects with positive responses to MSG. PMID:24744869

  7. Antinociceptive action of diphenyl diselenide in the nociception induced by neonatal administration of monosodium glutamate in rats.

    PubMed

    Rosa, Suzan G; Quines, Caroline B; da Rocha, Juliana T; Bortolatto, Cristiani F; Duarte, Thiago; Nogueira, Cristina W

    2015-07-01

    Monosodium glutamate (MSG) is a neuroexcitatory amino acid commonly used as flavoring of foods. MSG neonatal administration to animals leads to behavioral and physiological disorders in adulthood, including increased pain sensitivity. This study aimed to investigate the effect of diphenyl diselenide (PhSe)2, an organoselenium compound with pharmacological properties already documented, on nociception induced by MSG. Newborn Wistar rats received 10 subcutaneous injections of MSG at a dose of 4.0g/kg or saline (once daily). At the 60th day of life, the rats were daily treated with (PhSe)2 (1mg/kg) or vehicle (canola oil) by the intragastric route for 7 days. The behavioral tests (locomotor activity, hot plate, tail-immersion and mechanical allodynia) were carried out. Ex vivo assays were performed in samples of hippocampus to determine Na(+), K(+)-ATPase and Ca(2+)-ATPase activities, cytokine levels and [(3)H]glutamate uptake. The results demonstrated that MSG increased nociception in the hot plate test and in the mechanical allodynia stimulated by Von-Frey hair but did not alter the tail immersion test. (PhSe)2 reversed all nociceptive behaviors altered by MSG. MSG caused an increase in Na(+),K(+)-ATPase and Ca(2+)-ATPase activities and in pro-inflammatory cytokine levels and a decrease in the anti-inflammatory cytokine and in the [(3)H]glutamate uptake. (PhSe)2 was effective in reversing all alterations caused by MSG. The results indicate that (PhSe)2 had a potential antinociceptive and anti-inflammatory action in the MSG model. PMID:25841878

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

    PubMed

    Sasaki-Hamada, Sachie; Hojo, Yuki; Koyama, Hajime; Otsuka, Hayuma; Oka, Jun-Ichiro

    2015-05-01

    Glucose is the sole neural fuel for the brain and is essential for cognitive function. Abnormalities in glucose tolerance may be associated with impairments in cognitive function. Experimental obese model mice can be generated by an intraperitoneal injection of monosodium glutamate (MSG; 2 mg/g) once a day for 5 days from 1 day after birth. MSG-treated mice have been shown to develop glucose intolerance and exhibit chronic neuroendocrine dysfunction associated with marked cognitive malfunctions at 28-29  weeks old. Although hippocampal synaptic plasticity is impaired in MSG-treated mice, changes in synaptic transmission remain unknown. Here, we investigated whether glucose intolerance influenced cognitive function, synaptic properties and protein expression in the hippocampus. We demonstrated that MSG-treated mice developed glucose intolerance due to an impairment in the effectiveness of insulin actions, and showed cognitive impairments in the Y-maze test. Moreover, long-term potentiation (LTP) at Schaffer collateral-CA1 pyramidal synapses in hippocampal slices was impaired, and the relationship between the slope of extracellular field excitatory postsynaptic potential and stimulus intensity of synaptic transmission was weaker in MSG-treated mice. The protein levels of vesicular glutamate transporter 1 and GluA1 glutamate receptor subunits decreased in the CA1 region of MSG-treated mice. 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. PMID:25851080

  9. The Monosodium Glutamate Story: The Commercial Production of MSG and Other Amino Acids

    NASA Astrophysics Data System (ADS)

    Ault, Addison

    2004-03-01

    Examples of the industrial synthesis of pure amino acids are presented. The emphasis is on the synthesis of ( S )-glutamic acid and, to a lesser extent, ( S )-lysine and ( R,S )-methionine. These amino acids account for about 90% of the total world production of amino acids, ( S )-glutamic acid being used as a flavor-enhancing additive (MSG) for the human diet, and ( S )-lysine and ( R,S )-methionine as supplements for the feeding of domestic animals. Examples include chemical, enzymatic, and fermentation synthesis, and two clever continuous processes for the resolution of enantiomers. See Featured Molecules .

  10. Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity

    PubMed Central

    Nakadate, Kazuhiko; Motojima, Kento; Hirakawa, Tomoya; Tanaka-Nakadate, Sawako

    2016-01-01

    Chronic obesity is a known risk factor for metabolic syndrome. However, little is known about pathological changes in the small intestine associated with chronic obesity. This study investigated cellular and subcellular level changes in the small intestine of obese mice. In this study, a mouse model of obesity was established by early postnatal administration of monosodium glutamate. Changes in body weight were monitored, and pathological changes in the small intestine were evaluated using hematoxylin-eosin and Nissl staining and light and electron microscopy. Consequently, obese mice were significantly heavier compared with controls from 9 weeks of age. Villi in the small intestine of obese mice were elongated and thinned. There was reduced hematoxylin staining in the epithelium of the small intestine of obese mice. Electron microscopy revealed a significant decrease in and shortening of rough endoplasmic reticulum in epithelial cells of the small intestine of obese mice compared with normal mice. The decrease in rough endoplasmic reticulum in the small intestine epithelial cells of obese mice indicates that obesity starting in childhood influences various functions of the small intestine, such as protein synthesis, and could impair both the defense mechanism against invasion of pathogenic microbes and nutritional absorption. PMID:27437400

  11. Protective Effect of Calendula officinalis L. Flowers Against Monosodium Glutamate Induced Oxidative Stress and Excitotoxic Brain Damage in Rats.

    PubMed

    Shivasharan, B D; Nagakannan, P; Thippeswamy, B S; Veerapur, V P

    2013-07-01

    Monosodium glutamate (MSG) is a popular flavour enhancer used in food industries; however, excess MSG is neurotoxic. Oxidative stress is well documented in MSG induced neurotoxicity. The compounds having antioxidant and anti-inflammatory properties reportedly possess beneficial effects against various neurotoxic insults. Calendula officinalis Linn. flower extract (COE) is known for its potent antioxidant and anti-inflammatory activities. Hence, this present study has been designed to evaluate the neuroprotective effect of COE on MSG-induced neurotoxicity in rats. Adult Wistar rats were administered systemically for 7 days with MSG and after one h of MSG injection, rats were treated with COE (100 and 200 mg/kg) orally. At the end the treatment period, animals were assessed for locomotor activity and were sacrificed; brains were isolated for estimation of LPO, GSH, CAT, TT, GST, Nitrite and histopathological studies. MSG caused a significant alteration in animal behavior, oxidative defense (raised levels of LPO, nitrite concentration, depletion of antioxidant levels) and hippocampal neuronal histology. Treatment with COE significantly attenuated behavioral alterations, oxidative stress, and hippocampal damage in MSG-treated animals. Hence, this study demonstrates that COE protects against MSG-induced neurotoxicity in rats. The antioxidant and anti-inflammatory properties of COE may be responsible for its observed neuroprotective action. PMID:24426226

  12. Quercetin ameliorates glucose and lipid metabolism and improves antioxidant status in postnatally monosodium glutamate-induced metabolic alterations.

    PubMed

    Seiva, Fábio R F; Chuffa, Luiz Gustavo A; Braga, Camila Pereira; Amorim, João Paulo A; Fernandes, Ana Angélica H

    2012-10-01

    We reported the effects of quercetin on metabolic and hormonal profile as well as serum antioxidant activities in a model of MSG (monosodium glutamate)-induced obesity. Rats were divided into 4 groups: MSG group, submitted to neonatal treatment with high doses of MSG, administrated subcutaneously during 10 days, from 2 day-old; control groups, which received the same volume of saline. After completing 30 day-old, these groups were subdivided into 4 groups: control and MSG groups treated and non-treated with quercetin at doses of 75 mg/kg body weight (i.p.) over 42 days. BW gain and food consumption were higher in MSG treated rats and quercetin significantly reduced BW by 25%. While MSG increased triacylglycerol, total cholesterol and fractions, and reduced HDL concentrations, administration of quercetin normalized HDL-cholesterol and reduced others lipids. Insulin, leptin, glucose and creatinine levels were raised in MSG-treated rats and reduced after quercetin treatment. Alanine transaminase, aspartate transaminase, lactate dehydrogenase and alkaline phosphatase activities were lower after MSG-quercetin combination compared to rats given only MSG. MSG-quercetin combination augmented total protein and urea levels as well as glutathione peroxidase and superoxide dismutase activities in contrast to MSG-treated animals. Quercetin normalized serum lipid and glucose profile and minimized the MSG-related toxic effects, which was associated to its antioxidant properties. PMID:22809473

  13. Serological and Histological Examination of a Nonalcoholic Steatohepatitis Mouse Model Created via the Administration of Monosodium Glutamate

    PubMed Central

    Takai, Atsuko; Kajiyama, Yusuke; Sugiura, Anna; Negishi, Masatsugu; Miyakawa, Hiroshi

    2014-01-01

    The administration of monosodium glutamate (MSG) to mice induces hepatic steatosis and inflammation. In this study, we investigated the metabolic features of MSG-treated mice and the histological changes that occur in their livers and adipose tissue. MSG mice were prepared by subcutaneously injecting MSG into newborn C57BL/6J male mice. The control mice were subcutaneously injected with saline. Another group of mice was fed a methionine- and choline-deficient diet (MCD). Compared with the control mice, the MSG mice had higher serum levels of insulin and cholesterol than the control mice, whereas the opposite was true for the MCD mice. Microvesicular steatosis and inflammatory cell infiltration were detected in both the MSG and MCD mouse livers. Enlarged adipocytes and crown-like structures were observed in the epididymal fat of the MSG mice, whereas neither of these features was seen in the MCD mice. Flow cytometric analysis revealed increased frequencies of monocytes and M1 macrophages in the livers and epididymal fat tissue of the MSG mice, respectively. The MSG mice exhibited the characteristic liver histopathology of nonalcoholic steatohepatitis (NASH) as well as metabolic syndrome-like features, which suggested that MSG mice are a better model of human NASH than MCD mice.

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

    PubMed

    Prastiwi, D; Djunaidi, A; Partadiredja, G

    2015-11-01

    Monosodium glutamate (MSG) has been widely used throughout the world as a flavoring agent of food. However, MSG at certain dosages is also thought to cause damage to many organs, including cerebellum. This study aimed at investigating the effects of different doses of MSG on the motor coordination and the number of Purkinje cells of the cerebellum of Wistar rats. A total of 24 male rats aged 4 to 5 weeks were divided into four groups, namely, control (C), T2.5, T3, and T3.5 groups, which received intraperitoneal injection of 0.9% sodium chloride solution, 2.5 mg/g body weight (bw) of MSG, 3.0 mg/g bw of MSG, and 3.5 mg/g bw of MSG, respectively, for 10 consecutive days. 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. PMID:25697849

  15. Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity.

    PubMed

    Nakadate, Kazuhiko; Motojima, Kento; Hirakawa, Tomoya; Tanaka-Nakadate, Sawako

    2016-01-01

    Chronic obesity is a known risk factor for metabolic syndrome. However, little is known about pathological changes in the small intestine associated with chronic obesity. This study investigated cellular and subcellular level changes in the small intestine of obese mice. In this study, a mouse model of obesity was established by early postnatal administration of monosodium glutamate. Changes in body weight were monitored, and pathological changes in the small intestine were evaluated using hematoxylin-eosin and Nissl staining and light and electron microscopy. Consequently, obese mice were significantly heavier compared with controls from 9 weeks of age. Villi in the small intestine of obese mice were elongated and thinned. There was reduced hematoxylin staining in the epithelium of the small intestine of obese mice. Electron microscopy revealed a significant decrease in and shortening of rough endoplasmic reticulum in epithelial cells of the small intestine of obese mice compared with normal mice. The decrease in rough endoplasmic reticulum in the small intestine epithelial cells of obese mice indicates that obesity starting in childhood influences various functions of the small intestine, such as protein synthesis, and could impair both the defense mechanism against invasion of pathogenic microbes and nutritional absorption. PMID:27437400

  16. Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study.

    PubMed

    Geha, R S; Beiser, A; Ren, C; Patterson, R; Greenberger, P A; Grammer, L C; Ditto, A M; Harris, K E; Shaughnessy, M A; Yarnold, P R; Corren, J; Saxon, A

    2000-04-01

    Monosodium glutamate (MSG) has a long history of use in foods as a flavor enhancer. In the United States, the Food and Drug Administration has classified MSG as generally recognized as safe (GRAS). Nevertheless, there is an ongoing debate exists concerning whether MSG causes any of the alleged reactions. A complex of symptoms after ingestion of a Chinese meal was first described in 1968. MSG was suggested to trigger these symptoms, which were referred to collectively as Chinese Restaurant Syndrome. Numerous reports, most of them anecdotal, were published after the original observation. Since then, clinical studies have been performed by many groups, with varying degrees of rigor in experimental design ranging from uncontrolled open challenges to double-blind, placebo controlled (DBPC) studies. Challenges in subjects who reported adverse reactions to MSG have included relatively few subjects and have failed to show significant reactions to MSG. Results of surveys and of clinical challenges with MSG in the general population reveal no evidence of untoward effects. We recently conducted a multicenter DBPC challenge study in 130 subjects (the largest to date) to analyze the response of subjects who report symptoms from ingesting MSG. The results suggest that large doses of MSG given without food may elicit more symptoms than a placebo in individuals who believe that they react adversely to MSG. However, the frequency of the responses was low and the responses reported were inconsistent and were not reproducible. The responses were not observed when MSG was given with food. PMID:10736382

  17. Effect of different doses of monosodium glutamate on the thyroid follicular cells of adult male albino rats: a histological study

    PubMed Central

    Khalaf, Hanaa A; Arafat, Eetmad A

    2015-01-01

    Monosodium glutamate (MSG) is a major flavor enhancer used as a food additive. The present study investigates the effects of different doses of MSG on the morphometric and histological changes of the thyroid gland. 28 male albino rats were used. The rats were divided into four groups: group I control, group II, III and IV treated with MSG (0.25 g/kg, 3 g/kg, 6 g/kg daily for one month) respectively. The thyroid glands were dissected out and prepared for light and electron microscopic examination. Light microscopic examination of thyroid gland of group II revealed increase in follicular epithelial height. Groups III & IV showed decrease in the follicular diameter and irregularity in the shape of some follicles with discontinuity of basement membrane. Follicular hyperplasia was detected in some follicles with appearance of multiple pyknotic nuclei in follicular and interfollicular cells and multiple exfoliated cells in the colloid. In addition, areas of loss of follicular pattern were appeared in group IV. Immunohistochemical examination of BCL2 immunoexpression of the thyroid glands of groups III & IV reveals weak positive reaction in the follicular cells cytoplasm. Ultrathin sections examination of groups III & IV revealed follicular cells with irregular hyperchromatic nuclei, marked dilatation of rER and increased lysosomes with areas of short or lost apical microvilli. In addition, vacuolation of mitochondria was detected in group IV. The results displayed that MSG even at low doses is capable of producing alterations in the body weights and thyroid tissue function and histology. PMID:26884820

  18. Monosodium L-glutamate and dietary fat exert opposite effects on the proximal and distal intestinal health in growing pigs.

    PubMed

    Feng, Zemeng; Li, Tiejun; Wu, Chunli; Tao, Lihua; Blachier, Francois; Yin, Yulong

    2015-04-01

    The Chinese population has undergone rapid transition to a high-fat diet. Furthermore, monosodium L-glutamate (MSG) is widely used as a flavour enhancer in China. Previous studies have reported that high-fat diet modifies intestinal metabolism and physiology. However, little information is available on the effects of oral MSG on intestine, and no study focus on the interaction of dietary fat and MSG for intestinal health. The aim of the present study was to evaluate the effects of MSG and dietary fat on intestinal health in growing pigs, and to try to identify possible interactions between these 2 nutrients for such effects. A total of 32 growing pigs were used and fed with 4 isonitrogenous and isocaloric diets (basal diet, high-fat diet, basal diet with 3% MSG and high fat diet with 3% MSG). Parameters related to reactive oxygen species metabolism, epithelial morphology, pro-inflammation factors and tight junction protein expression and several species of intestinal microbe were measured. 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. PMID:25781200

  19. Stability of monosodium glutamate in green table olives and pickled cucumbers as a function of packing conditions and storage time.

    PubMed

    de Castro, Antonio; Sánchez, Antonio Higinio; Beato, Víctor Manuel; Casado, Francisco Javier; Montaño, Alfredo

    2014-01-01

    The effects of different packing conditions and storage times on the stability of monosodium glutamate (MSG) added to two different fermented vegetables (Spanish-type green table olives and pickled cucumbers) were studied. Factors such as packaging material (glass bottle versus plastic pouch), heat treatment (pasteurisation versus non-pasteurisation), and the presence or not of a preservative compound (potassium sorbate) were considered. The MSG content of pickled cucumbers was stable for up to 1 year of storage in all packing conditions studied. The MSG content also remained stable in pasteurised green table olives. On the contrary, MSG was extensively degraded (>75% degradation) after 54 weeks of storage in unpasteurised green olives with a higher degradation rate in glass bottles compared with plastic pouches. In the presence of potassium sorbate, MSG was also considerably degraded in olives packed in plastic pouches (>50% degradation), but hardly degraded in glass bottles. The results indicate that MSG degradation in olives is due to the action of both lactic acid bacteria and yeasts, with the formation of γ-aminobutyric acid as the major end-product. PMID:24720705

  20. Heterogeneous Nucleation of n-Butanol Vapor on Submicrometer Charged and Neutral Particles of Lactose and Monosodium Glutamate.

    PubMed

    Chen; Tao; Shu

    2000-04-01

    Condensation of a supersaturated vapor of n-butanol on monodisperse submicrometer particles of lactose and monosodium glutamate is investigated in a flow cloud chamber (FCC). The dependence of critical supersaturation S(cr) on the particle size in the range 30 to 90 nm is experimentally examined. The results show that the size dependence of S(cr) qualitatively agrees with that predicted by the Fletcher version of the Volmer theory of heterogeneous nucleation, but to a lesser degree. The experimental S(cr) is smaller than the theoretical prediction even with the line tension and surface diffusion taken into account, and they induce heterogeneous nucleation better than perfectly wetted particles. The discrepancy can not be fully accounted for by the effects of line tension and surface diffusion and the existing theory concerning the curvature-dependent surface tension. The condensation on single positive-charged particles of diameter 30, 60, and 90 nm is also examined. A lowering of S(cr) at an efficiency much larger than the prediction by Volmer's theory for ion-induced nucleation is observed, and the charge effect fades away as particle size increases. Copyright 2000 Academic Press. PMID:10708489

  1. Glycine regulates the production of pro-inflammatory cytokines in lean and monosodium glutamate-obese mice.

    PubMed

    Alarcon-Aguilar, F J; Almanza-Perez, Julio; Blancas, Gerardo; Angeles, Selene; Garcia-Macedo, Rebeca; Roman, Ruben; Cruz, Miguel

    2008-12-01

    Fat tissue plays an important role in the regulation of inflammatory processes. Increased visceral fat has been associated with a higher production of cytokines that triggers a low-grade inflammatory response, which eventually may contribute to the development of insulin resistance. In the present study, we investigated whether glycine, an amino acid that represses the expression in vitro of pro-inflammatory cytokines in Kupffer and 3T3-L1 cells, can affect in vivo cytokine production in lean and monosodium glutamate-induced obese mice (MSG/Ob mice). Our data demonstrate that glycine treatment in lean mice suppressed TNF-alpha transcriptional expression in fat tissue, and serum protein levels of IL-6 were suppressed, while adiponectin levels were increased. In MSG/Ob mice, glycine suppressed TNF-alpha and IL-6 gene expression in fat tissue and significantly reduced protein levels of IL-6, resistin and leptin. To determine the role of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in the modulation of this inflammatory response evoked by glycine, we examined its expression levels in fat tissue. Glycine clearly increased PPAR-gamma expression in lean mice but not in MSG/Ob mice. Finally, to identify alterations in glucose metabolism by glycine, we also examined insulin levels and other biochemical parameters during an oral glucose tolerance test. Glycine significantly reduced glucose tolerance and raised insulin levels in lean but not in obese mice. In conclusion, our findings suggest that glycine suppresses the pro-inflammatory cytokines production and increases adiponectin secretion in vivo through the activation of PPAR-gamma. Glycine might prevent insulin resistance and associated inflammatory diseases. PMID:18930730

  2. Effects of ad libitum ingestion of monosodium glutamate on weight gain in C57BL6/J mice.

    PubMed

    Ren, Xueying; Ferreira, Jozélia G; Yeckel, Catherine W; Kondoh, Takashi; de Araujo, Ivan E

    2011-01-01

    Although the umami compound monosodium glutamate (MSG) is a widely used flavor enhancer, controversy still persists regarding the effects of MSG intake on body weight. It has been claimed, in particular, that chronic MSG intake may result in excessive body weight gain and obesity. In this study we assessed the effects of chronic (16 weeks) ad libitum MSG on body weight and metabolism of C57BL6/J mice. Adult male mice were divided in four experimental groups and fed with either a low-fat (LF) or high-fat (HF) diet and with either two bottles of plain water or one bottle containing 1% MSG and another one containing water according to a factorial design. Mice were monitored weekly for body weight and food/fluid intake for 15 weeks. At the end of the experiments, the circulating levels of leptin, insulin, total protein, total cholesterol, triglyceride, blood urea nitrogen, and non-esterified fatty acids were also analyzed. Our results show that MSG intake did not influence body weight in either LF or HF groups. Interestingly, although animals overall displayed strong preferences for MSG against water, preferences were relatively higher in LF compared to HF group. Consistent with the body weight data, while significant differences in leptin, insulin, total cholesterol, and non-esterified fatty acids were found between HF and LF groups, such an effect was not influenced by MSG intake. Finally, indirect calorimetry measurements revealed similar energy expenditure levels between animals being presented water only and MSG only. In summary, our data does not support the notion that ad libitum MSG intake should trigger the development of obesity or other metabolic abnormalities. PMID:21389726

  3. Effect of NaCl/Monosodium Glutamate (MSG) Mixture on the Sensorial Properties and Quality Characteristics of Model Meat Products

    PubMed Central

    Chun, Ji-Yeon; Cho, Hyung-Yong; Min, Sang-Gi

    2014-01-01

    Sodium chloride is an important ingredient added to most of foods which contributes to flavor enhancement and food preservation but excess intake of sodium chloride may also cause various diseases such as heart diseases, osteoporosis and so on. Therefore, this study was carried out to investigate the effect of monosodium glutamate (MSG) as a salty flavor enhancer on the quality and sensorial properties of the NaCl/MSG complex and actual food system. For characterizing the spray-dried NaCl/MSG complex, surface dimension, morphology, rheology, and saltiness intensity were estimated by increasing MSG (0-2.0%) levels at a fixed NaCl concentration (2.0%). MSG levels had no effect of the characteristics of the NaCl/MSG complex, although the addition of MSG increased the surface dimension of the NaCl/MSG complex significantly (p<0.05). Furthermore, the effect of MSG on enhancing the salty flavor was not observed in the solution of the NaCl/MSG complex. In the case of an actual food system, model meat products (pork patties) were prepared by replacing NaCl with MSG. MSG enhanced the salty flavor, thereby increasing overall acceptability of pork patties. Replacement of NaCl with MSG (<1.0%) did not result in negative sensorial properties of pork patties, although quality deterioration such as high cooking loss was found. Nevertheless, MSG had a potential application in meat product formulation as a salty flavor enhancer or a partial NaCl replacer when meat products were supplemented with binding agents. PMID:26761490

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

    PubMed

    Abu-Taweel, Gasem M; A, Zyadah M; Ajarem, Jamaan S; Ahmad, Mohammad

    2014-01-01

    The present study was designed to investigate the in vivo effects of monosodium glutamate (MSG) and aspartame (ASM) individually and in combination on the cognitive behavior and biochemical parameters like neurotransmitters and oxidative stress indices in the brain tissue of mice. Forty male Swiss albino mice were randomly divided into four groups of ten each and were exposed to MSG and ASM through drinking water for one month. Group I was the control and was given normal tap water. Groups II and III received MSG (8 mg/kg) and ASM (32 mg/kg) respectively dissolved in tap water. Group IV received MSG and ASM together in the same doses. After the exposure period, the animals were subjected to cognitive behavioral tests in a shuttle box and a water maze. Thereafter, the animals were sacrificed and the neurotransmitters and oxidative stress indices were estimated in their forebrain tissue. 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. PMID:24556450

  5. Enrichment of anammox bacteria from three sludge sources for the startup of monosodium glutamate industrial wastewater treatment system.

    PubMed

    Li-dong, Shen; An-hui, Hu; Ren-cun, Jin; Dong-qing, Cheng; Ping, Zheng; Xiang-yang, Xu; Bao-lan, Hu

    2012-01-15

    Three activated sludges from a landfill leachate treatment plant (S1), a municipal sewage treatment plant (S2) and a monosodium glutamate (MSG) wastewater treatment plant (S3) were used as inocula to enrich anaerobic ammonium oxidation (anammox) bacteria for the startup of MSG industrial wastewater treatment system. After 360 days of cultivation using MSG wastewater, obvious anammox activity was observed in all three cultures. The maximum specific anammox activities of cultures S1, S2 and S3 were 0.11 kg N kg(-1) VSS day(-1), 0.09 kg N kg(-1) VSS day(-1) and 0.16 kg N kg(-1) VSS day(-1), respectively. Brownish-red anammox granules having diameters in the range of 0.2-1.0mm were visible in cultures S1 and S2, and large red granules having diameters in the range of 0.5-2.5mm were formed in culture S3 after 420 days of cultivation. Phylogenetic analysis of 16S rRNA genes showed that Kuenenia organisms were the dominant anammox species in all three cultures. The copy numbers of 16S rRNA genes of anammox bacteria in cultures S1, S2 and S3 were 6.8 × 10(7) copies mL(-1), 9.4 × 10(7) copies mL(-1) and 7.5 × 10(8) copies mL(-1), respectively. The results of this study demonstrated that anammox cultivation from conventional activated sludges was highly possible using MSG wastewater. Thus the anammox process has possibility of applying to the nitrogen removal from MSG wastewater. PMID:22104770

  6. Effect of NaCl/Monosodium Glutamate (MSG) Mixture on the Sensorial Properties and Quality Characteristics of Model Meat Products.

    PubMed

    Chun, Ji-Yeon; Kim, Byong-Soo; Lee, Jung-Gyu; Cho, Hyung-Yong; Min, Sang-Gi; Choi, Mi-Jung

    2014-01-01

    Sodium chloride is an important ingredient added to most of foods which contributes to flavor enhancement and food preservation but excess intake of sodium chloride may also cause various diseases such as heart diseases, osteoporosis and so on. Therefore, this study was carried out to investigate the effect of monosodium glutamate (MSG) as a salty flavor enhancer on the quality and sensorial properties of the NaCl/MSG complex and actual food system. For characterizing the spray-dried NaCl/MSG complex, surface dimension, morphology, rheology, and saltiness intensity were estimated by increasing MSG (0-2.0%) levels at a fixed NaCl concentration (2.0%). MSG levels had no effect of the characteristics of the NaCl/MSG complex, although the addition of MSG increased the surface dimension of the NaCl/MSG complex significantly (p<0.05). Furthermore, the effect of MSG on enhancing the salty flavor was not observed in the solution of the NaCl/MSG complex. In the case of an actual food system, model meat products (pork patties) were prepared by replacing NaCl with MSG. MSG enhanced the salty flavor, thereby increasing overall acceptability of pork patties. Replacement of NaCl with MSG (<1.0%) did not result in negative sensorial properties of pork patties, although quality deterioration such as high cooking loss was found. Nevertheless, MSG had a potential application in meat product formulation as a salty flavor enhancer or a partial NaCl replacer when meat products were supplemented with binding agents. PMID:26761490

  7. The effects of additives on the crystal habit of monosodium L-glutamate monohydrate

    NASA Astrophysics Data System (ADS)

    Sano, Chiaki; Nagashima, Nobuya; Kawakita, Tetsuya; Iitaka, Yoichi

    1990-01-01

    The effects of various amino acids and organic acids on the habit of MSG crystals have been investigated. The addition of L-alanine (L-Ala) and L-lysine (L-Lys) made the MSG crystals short and thick, but D-glutamic acid (D-Glu), γ-amino butylic acid (γ-ABA) and L-pyrrolidone carboxylic acid (L-PCA) made the crystals long and thin. HPLC analysis of the end and the side faces of the MSG crystals grown with the additives revealed that the concentrations of L-Lys and L-Ala were higher at the end faces than at the side faces; but those of D-Glu, γ-ABA and L-PCA were higher at the side faces than at the end faces. The facts indicate that habit modifications of the MSG crystals, brought about in the presence of these additives, are due to stereo-selective adsorption of the additives on the crystal faces. Finally, the cause leading to the differences in adsorption of the additives on the crystal faces of MSG is discussed in relation to the stacking density of L-Glu molecules and Na ions on each face using the results of the X-ray structure analysis.

  8. Sex differences in brain cholinergic activity in MSG-obese rats submitted to exercise.

    PubMed

    Sagae, Sara Cristina; Grassiolli, Sabrina; Raineki, Charlis; Balbo, Sandra Lucinei; Marques da Silva, Ana Carla

    2011-11-01

    Obesity is an epidemic disease most commonly caused by a combination of increased energy intake and lack of physical activity. The cholinergic system has been shown to be involved in the regulation of food intake and energy expenditure. Moreover, physical exercise promotes a reduction of fat pads and body mass by increasing energy expenditure, but also influences the cholinergic system. The aim of this study is to evaluate the interaction between physical exercise (swimming) and central cholinergic activity in rats treated with monosodium glutamate (MSG, a model for obesity) during infancy. Our results show that MSG treatment is able to induce obesity in male and female rats. Specifically, MSG-treated rats presented a reduced body mass and nasoanal length, and increased perigonadal and retroperitoneal fat pads in relation to the body mass. Physical exercise was able to reduce body mass in both male and female rats, but did not change the fat pads in MSG-treated rats. Increased food intake was only seen in MSG-treated females submitted to exercise. Cholinergic activity was increased in the cortex of MSG-treated females and physical exercise was able to reduce this activity. Thalamic cholinergic activity was higher in sedentary MSG-treated females and exercised MSG-treated males. Hypothalamic cholinergic activity was higher in male and female MSG-treated rats, and was not reduced by exercise in the 2 sexes. Taken together, these results show that MSG treatment and physical exercise have different effects in the cholinergic activity of males and females. PMID:22039988

  9. Impaired muscarinic type 3 (M3) receptor/PKC and PKA pathways in islets from MSG-obese rats.

    PubMed

    Ribeiro, Rosane Aparecida; Balbo, Sandra Lucinei; Roma, Letícia Prates; Camargo, Rafael Ludemann; Barella, Luiz Felipe; Vanzela, Emerielle Cristine; de Freitas Mathias, Paulo Cesar; Carneiro, Everardo Magalhães; Boschero, Antonio Carlos; Bonfleur, Maria Lúcia

    2013-07-01

    Monosodium glutamate-obese rats are glucose intolerant and insulin resistant. Their pancreatic islets secrete more insulin at increasing glucose concentrations, despite the possible imbalance in the autonomic nervous system of these rats. Here, we investigate the involvement of the cholinergic/protein kinase (PK)-C and PKA pathways in MSG β-cell function. Male newborn Wistar rats received a subcutaneous injection of MSG (4 g/kg body weight (BW)) or hyperosmotic saline solution during the first 5 days of life. At 90 days of life, plasma parameters, islet static insulin secretion and protein expression were analyzed. Monosodium glutamate rats presented lower body weight and decreased nasoanal length, but had higher body fat depots, glucose intolerance, hyperinsulinemia and hypertrigliceridemia. Their pancreatic islets secreted more insulin in the presence of increasing glucose concentrations with no modifications in the islet-protein content of the glucose-sensing proteins: the glucose transporter (GLUT)-2 and glycokinase. However, MSG islets presented a lower secretory capacity at 40 mM K(+) (P < 0.05). The MSG group also released less insulin in response to 100 μM carbachol, 10 μM forskolin and 1 mM 3-isobutyl-1-methyl-xantine (P < 0.05, P < 0.0001 and P < 0.01). These effects may be associated with a the decrease of 46 % in the acetylcholine muscarinic type 3 (M3) receptor, and a reduction of 64 % in PKCα and 36 % in PKAα protein expressions in MSG islets. Our data suggest that MSG islets, whilst showing a compensatory increase in glucose-induced insulin release, demonstrate decreased islet M3/PKC and adenylate cyclase/PKA activation, possibly predisposing these prediabetic rodents to the early development of β-cell dysfunction. PMID:23652999

  10. [Effect of long-term monosodium glutamate administration on structure and functional state of the stomach and body weight in rats].

    PubMed

    Falalieieva, T M; Kukhars'kyĭ, V M; Berehova, T V

    2010-01-01

    The influence of prolonged administration of monosodium glutamate (MSG) on basal gastric acid secretion, body weight and gastric mucosa in rats was studied. We found that 10-, 20-, 30-days feeding by MSG in doses 15 to 30 mg/kg (equivalent to I and 2 g/person) leads to erosive and ulcerative lesions of the gastric mucosa and an increased secretion of hydrochloric acid and an increased body weight. 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. PMID:20968043

  11. Supplementing chicken broth with monosodium glutamate reduces energy intake from high fat and sweet snacks in middle-aged healthy women.

    PubMed

    Imada, Toshifumi; Hao, Susan Shuzhen; Torii, Kunio; Kimura, Eiichiro

    2014-08-01

    Monosodium L-glutamate (MSG) and inosine monophosphate-5 (IMP) are flavor enhancers for umami taste. However, their effects on appetite and food intake are not well-researched. The objective of the current study was to test their additions in a broth preload on subsequent appetite ratings, energy intake and food choice. Eighty-six healthy middle-aged women with normal body weight received three preload conditions on 3 test days 1 week apart - a low-energy chicken flavor broth (200 ml) as the control preload, and broths with added MSG alone (0.5 g/100 ml, MSG broth) or in combination with IMP (0.05 g/100 ml) (MSG+ broth) served as the experimental conditions. Fifteen minutes after preload administration subjects were provided an ad libitum testing meal which consisted of 16 snacks varying in taste and fat content. MSG and MSG+ enhanced savory taste and broth properties of liking and pleasantness. In comparison with control, the MSG preload resulted in less consumption of total energy, as well as energy from sweet and high-fat snacks. Furthermore, MSG broth preload reduced added sugar intake. These findings were not observed after MSG+ preload. Appetite ratings were not different across the three preloads. Results suggest a potential role of MSG addition to a low-energy broth preload in subsequent energy intake and food choice. This trial was registered at clinicaltrials.gov as NCT01761045. PMID:24768895

  12. Both Dietary Supplementation with Monosodium L-Glutamate and Fat Modify Circulating and Tissue Amino Acid Pools in Growing Pigs, but with Little Interactive Effect

    PubMed Central

    Feng, Zemeng; Zhou, Xiaoli; Wu, Fei; Yao, Kang; Kong, Xiangfeng; Li, Tiejun; Blachier, Francois; Yin, Yulong

    2014-01-01

    Background The Chinese population has undergone rapid transition to a high-fat diet. Furthermore, monosodium L-glutamate (MSG) is widely used as a daily food additive in China. Little information is available on the effects of oral MSG and dietary fat supplementation on the amino acid balance in tissues. The present study aimed to determine the effects of both dietary fat and MSG on amino acid metabolism in growing pigs, and to assess any possible interactions between these two nutrients. Methods and Results Four iso-nitrogenous and iso-caloric diets (basal diet, high fat diet, basal diet with 3% MSG and high fat diet with 3% MSG) were provided to growing pigs. The dietary supplementation with fat and MSG used alone and in combination were found to modify circulating and tissue amino acid pools in growing pigs. Both dietary fat and MSG modified the expression of gene related to amino acid transport in jejunum. Conclusions Both dietary fat and MSG clearly influenced amino acid content in tissues but in different ways. Both dietary fat and MSG enhance the absorption of amino acids in jejunum. However, there was little interaction between the effects of dietary fat and MSG. PMID:24465415

  13. Lycopene modulates cholinergic dysfunction, Bcl-2/Bax balance, and antioxidant enzymes gene transcripts in monosodium glutamate (E621) induced neurotoxicity in a rat model.

    PubMed

    Sadek, Kadry; Abouzed, Tarek; Nasr, Sherif

    2016-04-01

    The effect of monosodium glutamate (MSG) on brain tissue and the relative ability of lycopene to avert these neurotoxic effects were investigated. Thirty-two male Wistar rats were distributed into 4 groups: group I, untreated (placebo); group II, injected with MSG (5 mg·kg(-1)) s.c.; group III, gastrogavaged with lycopene (10 mg·kg(-1)) p.o.; and group IV received MSG with lycopene with the same mentioned doses for 30 days. The results showed that MSG induced elevation in lipid peroxidation marker and perturbation in the antioxidant homeostasis and increased the levels of brain and serum cholinesterase (ChE), total creatine phosphokinase (CPK), creatine phosphokinase isoenzymes BB (CPK-BB), and lactate dehydrogenase (LDH). Glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities and gene expression were increased and glutathione content was reduced in the MSG-challenged rats, and these effects were ameliorated by lycopene. Furthermore, MSG induced apoptosis in brain tissues reflected in upregulation of pro-apoptotic Bax while lycopene upregulated the anti-apoptotic Bcl-2. 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. PMID:26900785

  14. Long-term ingestion of monosodium L-glutamate did not induce obesity, dyslipidemia or insulin resistance: a two-generation study in mice.

    PubMed

    Nakamura, Hidehiro; Kawamata, Yasuko; Kuwahara, Tomomi; Smriga, Miro; Sakai, Ryosei

    2013-01-01

    The use of monosodium glutamate (MSG) as a flavor enhancer spans more than 100 y and there are many studies indicating the safety of general use of MSG. Recently, however, Collison et al. (2010) reported a two-generation study with a low dose of MSG that caused abdominal obesity, insulin resistance and dyslipidemia in mice. Due to public health concerns over metabolic syndrome, their report merits careful analysis. The present study attempted to repeat the Collison et al. findings. Groups of male or female C57BL/6J mice were fed a control diet or one supplemented with high-fructose corn syrup (HFCS) at a level of 20%. Drinking water control was provided or treatment groups were given 0.064% MSG solution (w/v). Diets and MSG administration continued throughout mating and during gestation and lactation periods. To further investigate the effects of ingestion of MSG, the offspring were continued on the same dosing conditions until they reached 32 wk of age. MSG administration in mice fed a normal or a HFCS diet throughout gestation and for 32 wk after birth, did not affect growth, girth size, abdominal fat weight or body composition. This study reports that MSG did not trigger insulin resistance, dyslipidemia or hepatic steatosis, regardless of the diet, not reproducing the results of the above-mentioned study (Collison et al., 2010). PMID:23727643

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

    PubMed

    Castrogiovanni, Daniel; Gaillard, Rolf C; Giovambattista, Andrés; Spinedi, Eduardo

    2008-01-01

    In rats, neonatal treatment with monosodium L-glutamate (MSG) induces several metabolic and neuroendocrine abnormalities, which result in hyperadiposity. No data exist, however, regarding neuroendocrine, immune and metabolic responses to acute endotoxemia in the MSG-damaged rat. We studied the consequences of MSG treatment during the acute phase response of inflammatory stress. Neonatal male rats were treated with MSG or vehicle (controls, CTR) and studied at age 90 days. Pituitary, adrenal, adipo-insular axis, immune, metabolic and gonadal functions were explored before and up to 5 h after single sub-lethal i.p. injection of bacterial lipopolysaccharide (LPS; 150 microg/kg). Our results showed that, during the acute phase response of inflammatory stress in MSG rats: (1) the corticotrope-adrenal, leptin, insulin and triglyceride responses were higher than in CTR rats, (2) pro-inflammatory (TNFalpha) cytokine response was impaired and anti-inflammatory (IL-10) cytokine response was normal, and (3) changes in peripheral estradiol and testosterone levels after LPS varied as in CTR rats. 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. PMID:18382067

  16. The use of concentrated monosodium glutamate wastewater as a conditioning agent for adjusting acidity and minimizing ammonia volatilization in livestock manure composting.

    PubMed

    Liu, Li; Kong, Haimin; Lu, Beibei; Wang, Jibing; Xie, Yuan; Fang, Ping

    2015-09-15

    In this study, concentrated monosodium glutamate waste (CMGW) was proposed as a conditioning agent to adjust acidity and decrease ammonia (NH3) volatilization in thermophilic aerobic composting based on two incubation experiments. The results showed that with the addition of CMGW, NH3 volatilization of compost mixture under high temperature phase decreased significantly and pH met the current national standard within 5.5-8.5. When CMGW dosage increased to 2% (v/w), the decrease in NH3 volatilization was as high as 78.9%. This effect was enhanced by repeated application of CMGW. Furthermore, although the electrical conductivity increased with the application of CMGW, both the germination index and the microbial respiration of compost mixture implied that CMGW had no negative effects on the maturity of compost, instead, a comprehensive maturity might be accelerated. It was concluded that CMGW was an optional conditioning agent for thermophilic aerobic composting of livestock manure in regards to adjusting acidity and preventing nitrogen loss from NH3 volatilization. PMID:26164271

  17. Estradiol target neurons in the hypothalamic arcuate nucleus and lateral ventromedial nucleus of young adult, reproductively senescent, and monosodium glutamate-lesioned female golden hamsters

    SciTech Connect

    Blaha, G.C.; Lamperti, A.A.

    1983-09-01

    Histoautoradiographic methods were used to assess estrogen target neurons in the hypothalamic arcuate nucleus (ARC) and ventromedial nucleus, lateral portion (LVM), comparing young adult and aged female golden hamsters. A subgroup of young adult females had ARC lesions induced by monosodium glutamate at neonatal day 8. All were ovariectomized to remove endogenous estrogens. Controls were given nonradioactive estradiol. After /sup 3/H-estradiol (/sup 3/H-E2) was injected intravenously, hypothalami were removed, frozen, and processed for histoautoradiography. In the ARC and LVM the ratio of /sup 3/H-E2 labelled neurons to total neurons counted was significantly lower in the older animals. Young females with ARC lesions had very few /sup 3/H-E2 labelled neurons remaining in the ARC but had a normal complement in the LVM. Although /sup 3/H-E2 labelled ARC neurons were notably decreased in old females, those ARC neurons that were labelled in the old had virtually the same frequency distribution of the labelling index as in the young, suggesting no change in the average estrogen uptake per target cell.

  18. The Neuroprotective Effect of Dark Chocolate in Monosodium Glutamate-Induced Nontransgenic Alzheimer Disease Model Rats: Biochemical, Behavioral, and Histological Studies.

    PubMed

    Madhavadas, Sowmya; Kapgal, Vijaya Kumar; Kutty, Bindu M; Subramanian, Sarada

    2016-01-01

    The vulnerability to oxidative stress and cognitive decline continue to increase during both normal and pathological aging. Dietary changes and sedentary life style resulting in mid-life obesity and type 2 diabetes, if left uncorrected, further add to the risk of cognitive decline and Alzheimer disease (AD) in the later stages of life. Certain antioxidant agents such as dietary polyphenols, taken in adequate quantities, have been suggested to improve the cognitive processes. In this study, we examined the effect of oral administration of dark chocolate (DC) containing 70% cocoa solids and 4% total polyphenol content for three months at a dose of 500 mg/Kg body weight per day to 17-month-old monosodium glutamate treated obese Sprague-Dawley rats, earlier characterized as a nontransgenic AD (NTAD) rat model after reversal of obesity, diabetes, and consequent cognitive impairments. 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. PMID:26673833

  19. Physical exercise introduced after weaning enhances pancreatic islet responsiveness to glucose and potentiating agents in adult MSG-obese rats.

    PubMed

    Ribeiro, R A; Bonfleur, M L; Vanzela, E C; Zotti, A I; Scomparin, D X; Boschero, A C; Balbo, S L

    2014-08-01

    Physical exercise represents an alternative way to prevent and/or ameliorate chronic metabolic diseases. Disruption of sympathetic nervous system (SNS) activity contributes to adiposity in obese subjects. Here, we verified the preventive effect of swimming training upon adiposity, adrenal catecholamine storage, and pancreatic islet function in obese monosodium glutamate (MSG)-treated rats. Male neonatal Wistar rats received MSG (4 mg/g body weight) during the first 5 days of life and, at weaning, half of the rats were submitted to swimming training, 30 min/day, 3 days a week, until 90 days of age (exercised rats: MSGex). Half of the rats were used as controls (sedentary group, MSGsd). Exercise training (ET) decreased insulinemia and fat deposition in MSGex, and increased adrenal catecholamine content, compared with MSGsd rats. Insulinemia during the ivGTT was lower in MSGex rats, despite a lack of difference in glycemia. Swimming training enhanced insulin release in islets challenged by 2.8-8.3 mmol/l glucose, whereas, at supraphysiological glucose concentrations (11.1-16.7 mmol/l), MSGex islets secreted less insulin than MSGsd. No differences in insulin secretion were observed following l-arginine (Arg) or K(+) stimuli. In contrast, islets from MSGex rats secreted more insulin when exposed to carbachol (100 μmol/l), forskolin (10 μmol/l), or IBMX (1 mmol/l) at 8.3 mmol/l glucose. Additionally, MSGex islets presented a better epinephrine inhibition upon insulin release. These results demonstrate that ET prevented the onset of obesity in MSG rats, probably by enhancing adrenal catecholamine levels. ET ameliorates islet responsiveness to several compounds, as well as insulin peripheral action. PMID:24554535

  20. Low fish oil intake improves insulin sensitivity, lipid profile and muscle metabolism on insulin resistant MSG-obese rats

    PubMed Central

    2011-01-01

    Background Obesity is commonly associated with diabetes, cardiovascular diseases and cancer. The purpose of this study was to determinate the effect of a lower dose of fish oil supplementation on insulin sensitivity, lipid profile, and muscle metabolism in obese rats. Methods Monosodium glutamate (MSG) (4 mg/g body weight) was injected in neonatal Wistar male rats. Three-month-old rats were divided in normal-weight control group (C), coconut fat-treated normal weight group (CO), fish oil-treated normal weight group (FO), obese control group (Ob), coconut fat-treated obese group (ObCO) and fish oil-treated obese group (ObFO). Obese insulin-resistant rats were supplemented with fish oil or coconut fat (1 g/kg/day) for 4 weeks. Insulin sensitivity, fasting blood biochemicals parameters, and skeletal muscle glucose metabolism were analyzed. Results Obese animals (Ob) presented higher Index Lee and 2.5 fold epididymal and retroperitoneal adipose tissue than C. Insulin sensitivity test (Kitt) showed that fish oil supplementation was able to maintain insulin sensitivity of obese rats (ObFO) similar to C. There were no changes in glucose and HDL-cholesterol levels amongst groups. Yet, ObFO revealed lower levels of total cholesterol (TC; 30%) and triacylglycerol (TG; 33%) compared to Ob. Finally, since exposed to insulin, ObFO skeletal muscle revealed an increase of 10% in lactate production, 38% in glycogen synthesis and 39% in oxidation of glucose compared to Ob. Conclusions Low dose of fish oil supplementation (1 g/kg/day) was able to reduce TC and TG levels, in addition to improved systemic and muscle insulin sensitivity. These results lend credence to the benefits of n-3 fatty acids upon the deleterious effects of insulin resistance mechanisms. PMID:21526994

  1. Taste perception of monosodium glutamate and inosine monophosphate by 129P3/J and C57BL/6ByJ mice.

    PubMed

    Murata, Yuko; Beauchamp, Gary K; Bachmanov, Alexander A

    2009-10-19

    Our previous studies have shown that in long-term two-bottle preference tests, mice from the C57BL/6ByJ (B6) inbred strain drink more monosodium glutamate (MSG) and inosine monophosphate (IMP) than mice from the 129P3/J (129) inbred strain. The goal of this study was to examine whether this variation in consumption could be attributed to strain differences in perception of the taste quality of MSG and IMP. We developed a conditioned taste aversion (CTA) in B6 and 129 mice to 100 mM MSG or 10 mM IMP and used a brief-access taste assay to examine CTA generalization. B6 and 129 mice did not differ in the generalization patterns following CTA to MSG: mice from both strains generalized CTA from MSG to NaCl. In contrast, strain differences in the generalization patterns were evident following the CTA to IMP: while mice from both strains generalized CTA from IMP to MSG, 129 mice tended to have stronger CTA generalization to saccharin and d-tryptophan, both of which are perceived as sweet by humans. These data suggest that the strain differences in MSG consumption are not due to variation in perception of the taste quality of MSG. Instead, the differential intake of IMP likely reflects strain differences in the way the taste quality of IMP is perceived. Our data suggest that mice perceive MSG and IMP as complex taste stimuli: some taste components are shared between these two substances, but their relative intensity seems to be different for MSG and IMP. The amiloride-sensitive salt taste component is more prevalent in MSG than in IMP taste, and in B6 compared with 129 mice. PMID:19666040

  2. Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats

    PubMed Central

    Sanches, Jonas R.; França, Lucas M.; Chagas, Vinicyus T.; Gaspar, Renato S.; dos Santos, Kayque A.; Gonçalves, Luciana M.; Sloboda, Deborah M.; Holloway, Alison C.; Dutra, Richard P.; Carneiro, Everardo M.; Cappelli, Ana Paula G.; Paes, Antonio Marcus de A.

    2016-01-01

    Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed, and pulp-fruit, however. there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a twofold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10–1000 μg/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E β-cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated

  3. Effect of trans-fat, fructose and monosodium glutamate feeding on feline weight gain, adiposity, insulin sensitivity, adipokine and lipid profile.

    PubMed

    Collison, Kate S; Zaidi, Marya Z; Saleh, Soad M; Inglis, Angela; Mondreal, Rhea; Makhoul, Nadine J; Bakheet, Razan; Burrows, Joey; Milgram, Norton W; Al-Mohanna, Futwan A

    2011-07-01

    The incidence of obesity and type 2 diabetes mellitus (T2DM) is increasing, and new experimental models are required to investigate the diverse aspects of these polygenic diseases, which are intimately linked in terms of aetiology. Feline T2DM has been shown to closely resemble human T2DM in terms of its clinical, pathological and physiological features. Our aim was to develop a feline model of diet-induced weight gain, adiposity and metabolic deregulation, and to examine correlates of weight and body fat change, insulin homeostasis, lipid profile, adipokines and clinical chemistry, in order to study associations which may shed light on the mechanism of diet-induced metabolic dysregulation. We used a combination of partially hydrogenated vegetable shortening and high-fructose corn syrup to generate a high-fat-high-fructose diet. The effects of this diet were compared with an isoenergetic standard chow, either in the presence or absence of 1.125 % dietary monosodium glutamate (MSG). Dual-energy X-ray absorptiometry body imaging and a glucose tolerance test were performed. The present results indicate that dietary MSG increased weight gain and adiposity, and reduced insulin sensitivity (P < 0.05), whereas high-fat-high-fructose feeding resulted in elevated cortisol and markers of liver dysfunction (P < 0.01). The combination of all three dietary constituents resulted in lower insulin levels and elevated serum β-hydroxybutyrate and cortisol (P < 0.05). This combination also resulted in a lower first-phase insulin release during glucose tolerance testing (P < 0.001). In conclusion, markers of insulin deregulation and metabolic dysfunction associated with adiposity and T2DM can be induced by dietary factors in a feline model. PMID:21429276

  4. Sub-chronic concomitant ingestion of L-arginine and monosodium glutamate improves feed efficiency, lipid metabolism and antioxidant capacity in male Wistar rats.

    PubMed

    Egbuonu, Anthony C Cemaluk

    2012-03-15

    The use of L-arginine (ARG) is common in supplements, whereas, Monosodium Glutamate (MSG) is widely used as flavor enhancing food additive. Thus, ARG and MSG may be present together in human diets, warranting this study aimed at investigating the effect of concomitant ingestion of ARG and MSG on some biochemical indices in male rats. Twelve male albino rats were grouped into three (n = 4) and concomitantly exposed to 0:0, 20:5 and 60:15 mg kg(-1) of ARG:MSG. Exposure was peroral and every twenty four h for 28 days. ARG plus MSG treatment caused a significant (p < or = 0.05) increase in Feed Efficiency (FE) (Low dose: 5.23 +/- 22%; High dose: 5.60 +/- 11%), whereas, it decreased (p < or = 0.05) the serum Total Cholesterol (T-Chol) (low dose: 80.83 +/- 0.11 mg/100 mL, high dose: 92.55 +/- 0.14 mg/100 mL), triacylglycerol (TAG) (low dose: 179.91 +/- 0.09 mg/100 mL, high dose: 119.77 +/- 0.32 mg/100 mL) and malondialdehyde (MDA) (low dose: 5.00 +/- 0.07 mg/100 mL, high dose: 24.36 +/- 0.10 mg/100 mL) concentrations of the rats in a dose dependent manner. However, (at the high dose) the increase in Body Weight (BW) (0.08 +/- 0.07 kg), Feed Intake (FI) (0.40 +/- 0.03 kg) and Water Intake (WI) (0.65 +/- 0.18 L) induced by ARG plus MSG exposure was not significant (p < or = 0.05), suggesting non treatment related effect on these routine parameters. However, exposure to ARG plus MSG may significantly improve feed efficiency, lipid metabolism and antioxidant capacity in the male rats. PMID:24175428

  5. Diphenyl diselenide elicits antidepressant-like activity in rats exposed to monosodium glutamate: A contribution of serotonin uptake and Na(+), K(+)-ATPase activity.

    PubMed

    Quines, Caroline B; Rosa, Suzan G; Velasquez, Daniela; Da Rocha, Juliana T; Neto, José S S; Nogueira, Cristina W

    2016-03-15

    Depression is a disorder with symptoms manifested at the psychological, behavioral and physiological levels. Monosodium glutamate (MSG) is the most widely used additive in the food industry; however, some adverse effects induced by this additive have been demonstrated in experimental animals and humans, including functional and behavioral alterations. The aim of this study was to investigate the possible antidepressant-like effect of diphenyl diselenide (PhSe)2, an organoselenium compound with pharmacological properties already documented, in the depressive-like behavior induced by MSG in rats. Male and female newborn Wistar rats were divided in control and MSG groups, which received, respectively, a daily subcutaneous injection of saline (0.9%) or MSG (4g/kg/day) from the 1st to 5th postnatal day. At 60th day of life, animals received (PhSe)2 (10mg/kg, intragastrically) 25min before spontaneous locomotor and forced swimming tests (FST). The cerebral cortices of rats were removed to determine [(3)H] serotonin (5-HT) uptake and Na(+), K(+)-ATPase activity. A single administration of (PhSe)2 was effective against locomotor hyperactivity caused by MSG in rats. (PhSe)2 treatment protected against the increase in the immobility time and a decrease in the latency for the first episode of immobility in the FST induced by MSG. Furthermore, (PhSe)2 reduced the [(3)H] 5-HT uptake and restored Na(+), K(+)-ATPase activity altered by MSG. In the present study a single administration of (PhSe)2 elicited an antidepressant-like effect and decrease the synaptosomal [(3)H] 5-HT uptake and an increase in the Na(+), K(+)-ATPase activity in MSG-treated rats. PMID:26738966

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

    PubMed

    Quines, Caroline B; Rosa, Suzan G; Chagas, Pietro M; da Rocha, Juliana T; Dobrachinski, Fernando; Carvalho, Nélson R; Soares, Félix A; da Luz, Sônia C Almeida; Nogueira, Cristina W

    2016-01-01

    The metabolic syndrome is a group of metabolic alterations considered a worldwide public health problem. Organic selenium compounds have been reported to have many different pharmacological actions, such as anti-hypercholesterolemic and anti-hyperglycemic. The aim of this study was to evaluate the effect of p-chloro-diphenyl diselenide (p-ClPhSe)2, an organic selenium compound, in a model of obesity induced by monosodium glutamate (MSG) administration in rats. The rats were treated during the first ten postnatal days with MSG and received (p-ClPhSe)2 (10 mg/kg, intragastrically) from 45th to 51 th postnatal day. Glucose, lipid and lactate levels were determined in plasma of rats. Glycogen levels and activities of tyrosine aminotransferase, hexokinase, citrate synthase and glucose-6-phosphatase (G-6-Pase) were determined in livers of rats. Renal G-6-Pase activity was also determined. The purine content [Adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate] and mitochondrial functionality in the liver were also investigated. p-(ClPhSe)2 did not alter the reduction in growth performance and in the body weight caused by MSG but reduced epididymal fat deposition of rats. p-(ClPhSe)2 restored glycemia, triglycerides, cholesterol and lactate levels as well as the glucose metabolism altered in rats treated with MSG. p-(ClPhSe)2 restored hepatic mitochondrial dysfunction and the decrease in citrate synthase activity and ATP and ADP levels caused by MSG in rats. In summary, (p-ClPhSe)2 had homeostatic effects on glucose metabolism and mitochondrial function alterations induced by MSG administration to rats. PMID:26293481

  7. Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats.

    PubMed

    Sanches, Jonas R; França, Lucas M; Chagas, Vinicyus T; Gaspar, Renato S; Dos Santos, Kayque A; Gonçalves, Luciana M; Sloboda, Deborah M; Holloway, Alison C; Dutra, Richard P; Carneiro, Everardo M; Cappelli, Ana Paula G; Paes, Antonio Marcus de A

    2016-01-01

    Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed, and pulp-fruit, however. there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a twofold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10-1000 μg/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E β-cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated

  8. Monosodium L-glutamate in soup reduces subsequent energy intake from high-fat savoury food in overweight and obese women.

    PubMed

    Miyaki, Takashi; Imada, Toshifumi; Hao, Susan Shuzhen; Kimura, Eiichiro

    2016-01-14

    The umami seasoning, monosodium L-glutamate (MSG), has been shown to increase satiety in normal body weight adults, although the results have not been consistent. The satiety effect of MSG in overweight and obese adults has not been examined yet. The objective of the present study was to investigate the effect of MSG in a vegetable soup on subsequent energy intakes as well as food selection in overweight and obese adult women without eating disorders. A total of sixty-eight overweight and obese women (BMI range: 25·0-39·9 kg/m²), otherwise healthy, were recruited to our study. A fixed portion (200 ml) of control vegetable soup or the same soup with added MSG (0·5 g/100 ml) was provided 10 min before an ad libitum lunch and an ad libitum snack in the mid-afternoon. The control soup had equivalent amount of Na to the soup with added MSG. Energy intakes at the ad libitum lunch and ad libitum snack time after the soup preload were assessed using a randomised, double-blind, two-way cross-over design. The soup with MSG in comparison with the control soup resulted in significantly lower consumption of energy at lunch. The addition of MSG in the soup also reduced energy intake from high-fat savoury foods. The soup with MSG showed lower but no significant difference in energy intake at mid-afternoon. The addition of umami seasoning MSG in a vegetable soup may decrease subsequent energy intake in overweight and obese women who do not have eating disorders. PMID:26455957

  9. Neonatal monosodium glutamate treatment counteracts circadian arrhythmicity induced by phase shifts of the light-dark cycle in female and male Siberian hamsters.

    PubMed

    Prendergast, Brian J; Onishi, Kenneth G; Zucker, Irving

    2013-07-12

    Studies of rats and voles suggest that distinct pathways emanating from the anterior hypothalamic-retrochiasmatic area and the mediobasal hypothalamic arcuate nucleus independently generate ultradian rhythms (URs) in hormone secretion and behavior. We evaluated the hypothesis that destruction of arcuate nucleus (ARC) neurons, in concert with dampening of suprachiasmatic nucleus (SCN) circadian rhythmicity, would compromize the generation of ultradian rhythms (URs) of locomotor activity. Siberian hamsters retain-->of both sexes treated neonatally with monosodium glutamate (MSG) that destroys ARC neurons were subjected in adulthood to a circadian disrupting phase-shift protocol (DPS) that produces SCN arrhythmia. MSG treatments induced hypogonadism and obesity, retain-->and markedly reduced the size of the optic chiasm and optic nerves. MSG-treated hamsters exhibited normal entrainment to the light-dark cycle, but MSG treatretain-->ment counteracted the circadian arrhythmicity induced by the DPS protocol: only 6% of retain-->MSG-treated hamsters exhibited circadian arrhythmia, whereas 50% of control hamsters were circadian disrupted. In MSG-treated hamsters that retained circadian rhythmicity after DPS treatment, quantitative parameters of URs appeared normal, but in the two MSG-treated hamsters that became circadian arrhythmic after DPS, both dark-phase and light-phase URs were abolished. Although preliminary, these data are consistent with reports in voles suggesting that the combined disruption of SCN and ARC function impairs the expression of behavioral URs. The data also suggest that light thresholds for entrainment of circadian rhythms may be lower than those required to disrupt circadian organization. PMID:23701725

  10. New frontiers in gut nutrient sensor research: monosodium L-glutamate added to a high-energy, high-protein liquid diet promotes gastric emptying: a possible therapy for patients with functional dyspepsia.

    PubMed

    Kusano, Motoyasu; Zai, Hiroaki; Hosaka, Hiroko; Shimoyama, Yasuyuki; Nagoshi, Atsuto; Maeda, Masaki; Kawamura, Osamu; Mori, Masatomo

    2010-01-01

    Functional dyspepsia is a clinical syndrome that features abdominal symptoms centered in the upper abdomen without an organic basis. Three possible mechanisms of gastric dysfunction could be related to functional dyspepsia: 1) delayed gastric emptying, 2) impaired gastric accommodation to food intake, and 3) hypersensitivity to gastric distention. Delayed gastric emptying has been suggested to lead to prolonged antral distension that causes dyspeptic symptoms. Delayed gastric emptying is therefore a focal point of debate about anorexia caused by dyspepsia, and prokinetic agents are often administered in Japan for its treatment. Recently, we found that addition of monosodium L-glutamate (MSG) to a high-energy liquid diet rich in casein promoted gastric emptying in healthy men. Therefore, another potential method to improve delayed gastric emptying could be enhancement of chemosensors that activate the autonomic nervous system innervating the gastrointestinal tract. In conclusion, enrichment with glutamate promoted gastric emptying after intake of a high-protein meal, suggesting that free glutamate is important for protein digestion and that MSG may be helpful for management of delayed gastric emptying in patients with functional dyspepsia. PMID:20093786

  11. 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.

    PubMed

    Roman-Ramos, Ruben; Almanza-Perez, Julio C; Garcia-Macedo, Rebeca; Blancas-Flores, Gerardo; Fortis-Barrera, Angeles; Jasso, Edgar I; Garcia-Lorenzana, Mario; Campos-Sepulveda, Alfonso E; Cruz, Miguel; Alarcon-Aguilar, Francisco J

    2011-06-01

    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. PMID:21205225

  12. In-capillary derivatization with o-phthalaldehyde in the presence of 3-mercaptopropionic acid for the simultaneous determination of monosodium glutamate, benzoic acid, and sorbic acid in food samples via capillary electrophoresis with ultraviolet detection.

    PubMed

    Aung, Hnin-Pwint; Pyell, Ute

    2016-06-01

    For the rapid simultaneous determination of monosodium glutamate (MSG), benzoic acid (BA), and sorbic acid (SA) in canned food and other processed food samples, we developed a method that combines in-capillary derivatization with separation by capillary electrophoresis. This method employs the rapid derivatization of MSG with o-phthalaldehyde (OPA) in the presence of 3-mercaptopropionic acid (3-MPA) and enables the detection of the resulting OPA-MSG derivative and of non-derivatized BA and SA at 230nm. The composition of the background electrolyte and the parameters of derivatization and separation are as follows: 25mM borax containing 5mM OPA and 6mM 3-MPA, separation voltage 25mV, injection at 30mbar for 20s, and column temperature 25°C. Because of the high reaction rate and suitably adapted effective electrophoretic mobilities, band broadening due to the derivatization reaction at the start of the separation process is kept to a minimum. The optimized method is validated with respect to LOD, LOQ, linearity, recovery, and precision. This method can be applied to real samples such as soy, fish, oyster and sweet and sour chili sauces after application of appropriate clean-up steps. Mechanisms of zone broadening and zone focusing are discussed showing the validity of the employed theoretical approach regarding the dependence of the peak shape for OPA-MSG on the concentration of MSG in the sample. PMID:27156753

  13. The effects of black garlic (Allium sativum L.) ethanol extract on the estimated total number of Purkinje cells and motor coordination of male adolescent Wistar rats treated with monosodium glutamate.

    PubMed

    Aminuddin, M; Partadiredja, G; Sari, D C R

    2015-03-01

    A number of studies have indicated that monosodium glutamate (MSG) might cause negative effects on the nervous system, including in the cerebellum. Garlic (Allium sativum) has long been known as a flavouring agent and a traditional remedy for various illnesses. The present study aimed at investigating the effects of garlic on the motor coordination and the number of Purkinje cells present in rats treated with MSG. A total of 25 male Wistar rats aged 4 to 5 weeks old were used in this study and were divided into five groups, namely a negative control (C-) group, which received 0.9 % NaCl solution, a positive control (C+) group, which received MSG, and three treated groups, which received 2 mg/g bw of MSG and 2.5 mg (T2.5), 5 mg (T5), or 10 mg (T10) of black garlic solution per oral administration (per 200 g bw), respectively. All treatments were carried out for 10 days. Upon the end of the treatment, the motor performance of all rats were tested using the rotarod apparatus. The rats were subsequently sacrificed, and the cerebella of the rats were processed for stereological analyses. It has been found that the number of Purkinje cells of the cerebella of all treated groups were significantly higher than that of the group treated with MSG only. No changes in motor coordination function were observed as a result of MSG treatment. PMID:24737450

  14. 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.

    PubMed

    Hermawati, Ery; Sari, Dwi Cahyani Ratna; Partadiredja, Ginus

    2015-09-01

    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. We have investigated the effects of black garlic, a fermented form of garlic, on spatial memory and estimated the total number of pyramidal cells of the hippocampus in adolescent male Wistar rats treated with MSG. Twenty-five rats were divided into five groups: C- group, which received normal saline; C+ group, which was exposed to 2 mg/g body weight (bw) of MSG; three treatment groups (T2.5, T5, T10), which were treated with black garlic extract (2.5, 5, 10 mg/200 g bw, respectively) and MSG. 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. The estimated total number of pyramidal cells in the CA1 region of the hippocampus was higher in all treated groups than that of the C+ group. Based on these results, we conclude that combined administration of black garlic and MSG may alter the spatial memory functioning and total number of pyramidal neurons of the CA1 region of the hippocampus of rats. PMID:25422084

  15. Metabolic fate and function of dietary glutamate in the gut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glutamate is a major constituent of dietary protein and is also consumed in many prepared foods as an additive in the form of monosodium glutamate. Evidence from human and animal studies indicates that glutamate is a major oxidative fuel for the gut and that dietary glutamate is extensively metabol...

  16. Emerging aspects of dietary glutamate metabolism in the developing gut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glutamate is a major constituent of dietary protein and is also consumed in many prepared foods as a flavour additive in the form of monosodium glutamate (MSG). Evidence from human and animal studies indicates that glutamate is the major oxidative fuel for the gut and that dietary glutamate is exten...

  17. Effect of the umami peptides on the ligand binding and function of rat mGlu4a receptor might implicate this receptor in the monosodium glutamate taste transduction

    PubMed Central

    Monastyrskaia, Katherine; Lundstrom, Kenneth; Plahl, Doris; Acuna, Gonzalo; Schweitzer, Christophe; Malherbe, Pari; Mutel, Vincent

    1999-01-01

    The effect of several metabotropic ligands and di- or tripeptides were tested on the binding of [3H]-L(+)-2-amino-4-phosphonobutyric acid ([3H]-L-AP4) on rat mGlu4 receptor. For selected compounds, the functional activity was determined on this receptor using the guanosine-5′[γ-35S]-thiotriphosphate [γ-35S]-GTP binding assay.Using the scintillation proximity assay, [3H]-L-AP4 saturation analysis gave binding parameters KD and Bmax values of 150 nM and 9.3 pmoles mg−1 protein, respectively. The specific binding was inhibited concentration-dependently by several mGlu receptor ligands, and their rank order of affinity was established.Several peptides inhibited the [3H]-L-AP4 binding with the following rank order of potency: glutamate-glutamate>glutamate-glutamate-leucine=aspartate - glutamate>>glutamate - glutamate-aspartate>lactoyl-glutamate>>aspartate-aspartate. Aspartate-phenylalanine-methyl ester (aspartame) was inactive up to 1 mM and guanosine-5′-monophosphate and inosine-5′-monophosphate were inactive up to 100 μM.The [γ-35S]-GTP binding functional assay was used to determine the agonist activities of the different compounds. For the rat mGlu4 agonists, L-AP4 and L-glutamate, the correlation between their occupancy and activation of the receptor was close to one. The peptides, Glu-Glu, Asp-Glu and Glu-Glu-Asp failed to stimulate the [γ-35S]-GTP binding at receptor occupancy greater than 80% and Glu-Glu-Leu appeared to be a weak partial agonist. These peptides did not elicit a clear dose-dependent umami perception. However, Glu-lac showed a good correlation between its potency to stimulate the [γ-35S]-GTP binding and its affinity for displacement of [3H]-L-AP4 binding. These data are in agreement with the peptide taste assessment in human subjects, which showed that the acid derivatives of glutamate had characteristics similar to umami. PMID:10556940

  18. The Crystallization of Monosodium Urate

    PubMed Central

    Martillo, Miguel A.; Nazzal, Lama; Crittenden, Daria B.

    2014-01-01

    Gout is a common crystal-induced arthritis, in which monosodium urate (MSU) crystals precipitate within joints and soft tissues and elicit an inflammatory response. The causes of elevated serum urate and the inflammatory pathways activated by MSU crystals have been well studied, but less is known about the processes leading to crystal formation and growth. Uric acid, the final product of purine metabolism, is a weak acid that circulates as the deprotonated urate anion under physiologic conditions, and combines with sodium ions to form MSU. MSU crystals are known to have a triclinic structure, in which stacked sheets of purine rings form the needle-shaped crystals that are observed microscopically. Exposed, charged crystal surfaces are thought to allow for interaction with phospholipid membranes and serum factors, playing a role in the crystal-mediated inflammatory response. While hyperuricemia is a clear risk factor for gout, local factors have been hypothesized to play a role in crystal formation, such as temperature, pH, mechanical stress, cartilage components, and other synovial and serum factors. Interestingly, several studies suggest that MSU crystals may drive the generation of crystal-specific antibodies that facilitate future MSU crystallization. Here, we review MSU crystal biology, including a discussion of crystal structure, effector function, and factors thought to play a role in crystal formation. We also briefly compare MSU biology to that of uric acid stones causing nephrolithasis, and consider the potential treatment implications of MSU crystal biology. PMID:24357445

  19. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #071311

    SciTech Connect

    Taylor-Pashow, K.

    2011-10-04

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.071311 qualification and 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process.

  20. Analysis of Harrell Monosodium Titanate Lot #46000824120

    SciTech Connect

    Taylor-Pashow, K. M.L.

    2013-01-23

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #46000824120 qualification and the 16 verification samples failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids.

  1. Analysis of Harrell Monosodium Titanate Lot #46000908120

    SciTech Connect

    Taylor-Pashow, K. M.L.

    2013-01-23

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #46000908120 qualification and the 16 verification samples failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids.

  2. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #46000619120

    SciTech Connect

    Taylor-Pashow, K.

    2012-09-06

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #46000619120 qualification and the 13 verification samples met each of the selected specification requirements that were tested and, consequently, the material is acceptable for use in the ARP process.

  3. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #052511

    SciTech Connect

    Taylor-Pashow, K.

    2011-08-22

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.052511 qualification and 14 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process.

  4. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #46000524120

    SciTech Connect

    Taylor-Pashow, K.

    2012-08-29

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.46000524120 qualification and the 14 verification samples met each of the selected specification requirements that were tested and, consequently, the material is acceptable for use in the ARP process.

  5. Intragastric administration of glutamate increases REM sleep in rats.

    PubMed

    Datta, Karuna; Kumar, Deependra; Mallick, Hruda Nanda

    2013-10-01

    Monosodium glutamate, a umami taste substance is commonly used flavor enhancer. The effect of intragastric administration of 1.5 ml of 0.12M monosodium glutamate on sleep-wake was studied in 10 adult male Wistar rats. Sleep-wake parameters were recorded through chronically implanted electroencephalogram, electrooculogram and electromyogram electrodes using a digital recording system (BIOPAC system Inc. BSL PRO 36, USA). The sleep-wake was recorded for 6h after the intragastric administration of either glutamate or saline. Sleep-wake stages were analyzed as wake, slow wave sleep and REM sleep. Compared to saline, intragastric administration of glutamate significantly increased REM sleep duration and episode frequency. REM sleep duration was increased in all the three 2h bins, 10:00-12:00 h (p=0.037), 12:00-14:00 h (p=0.037) and 14:00-16:00 h (p=0.007). The slow wave sleep and total sleep time were not affected. It is concluded that intragastric glutamate administration increases REM sleep. PMID:24055576

  6. Glutamate. Its applications in food and contribution to health.

    PubMed

    Jinap, S; Hajeb, P

    2010-08-01

    This article reviews application of glutamate in food and its benefits and role as one of the common food ingredients used. Monosodium glutamate is one of the most abundant naturally occurring amino acids which frequently added as a flavor enhancer. It produced a unique taste that cannot be provided by other basic taste (saltiness, sourness, sweetness and bitterness), referred to as a fifth taste (umami). Glutamate serves some functions in the body as well, serving as an energy source for certain tissues and as a substrate for glutathione synthesis. Glutamate has the potential to enhance food intake in older individuals and dietary free glutamate evoked a visceral sensation from the stomach, intestine and portal vein. Small quantities of glutamate used in combination with a reduced amount of table salt during food preparation allow for far less salt to be used during and after cooking. Because glutamate is one of the most intensely studied food ingredients in the food supply and has been found safe, the Joint Expert Committee on Food Additives of the United Nations Food and Agriculture Organization and World Health Organization placed it in the safest category for food additives. Despite a widespread belief that glutamate can elicit asthma, migraine headache and Chinese Restaurant Syndrome (CRS), there are no consistent clinical data to support this claim. In addition, findings from the literature indicate that there is no consistent evidence to suggest that individuals may be uniquely sensitive to glutamate. PMID:20470841

  7. Flavor Preferences Conditioned by Dietary Glutamate.

    PubMed

    Ackroff, Karen; Sclafani, Anthony

    2016-07-01

    Our understanding of the molecular basis of umami taste and its appetitive qualities has been greatly aided by studies in laboratory rodents. This review describes methods for testing responses to the prototypical umami substance monosodium glutamate (MSG) in rodents. Two techniques, forced exposure to MSG and 2-bottle choice tests with ascending concentrations, were used to evaluate the responses to the taste of umami itself, and 2 other methods used oral or postoral MSG to modify the responses to other flavors. Intake and preference for MSG are enhanced in mice by experience with MSG and with other nutrients with positive postoral effects. In addition, flavor preferences are enhanced in mice and rats by gastric or intestinal MSG infusions via an associative learning process. Even mice with an impaired or absent ability to taste MSG can learn to prefer a flavor added to an MSG solution, supporting the notion that glutamate acts postorally. The more complex flavor of dashi seasoning, which includes umami substances (inosinate, glutamate), is attractive to rodents, but dashi does not condition flavor preferences. Details of the postoral glutamate detection process and the nature of the signal involved in learned preferences are still uncertain but probably involve gastric or intestinal sensors or both and vagal transmission. Some findings suggest that postoral glutamate effects may enhance food preferences in humans, but this requires further study. PMID:27422522

  8. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT 46000824120

    SciTech Connect

    Taylor-Pashow, K.

    2014-04-09

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The original Harrell Industries Lot #46000824120 qualification and 16 verification samples received in September 2012 failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids. The lot was returned to the vendor, and in February 2014 a new qualification sample and set of 14 verification samples were received from this lot. The new lot met each of the selected specification requirements that were tested and, consequently, the material is acceptable for use in the ARP process.

  9. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT 46000908120

    SciTech Connect

    Taylor-Pashow, K.

    2014-04-09

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The original Harrell Industries Lot #46000908120 qualification and 16 verification samples received in October 2012 failed to meet the specification for weight percent solids. All of the pails sampled and tested contained less than 15 wt % MST solids. The lot was returned to the vendor, and in February 2014 a new qualification sample and set of 16 verification samples were received from this lot. The new lot met each of the selected specification requirements that were tested and, consequently, the material is acceptable for use in the ARP process.

  10. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #120111

    SciTech Connect

    Shehee, T.

    2012-02-21

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.120111 qualification and the first 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process. Analyses of Pail 125 verification sample fails the criteria for solids content and has measurably lower pH, density, and total bottle weight. The verification sample for Pail 125 was retested for weight percent solids after checking that all of the solids had been suspended. The sample again failed to meet acceptance criteria. SRNL recommends accepting Pails 1 through 120. Pails 121 through 125 should be rejected and returned to the vendor.

  11. Extracellular expression of glutamate decarboxylase B in Escherichia coli to improve gamma-aminobutyric acid production.

    PubMed

    Zhao, Anqi; Hu, Xiaoqing; Li, Ye; Chen, Cheng; Wang, Xiaoyuan

    2016-12-01

    Escherichia coli overexpressing glutamate decarboxylase GadB can produce gamma-aminobutyric acid with addition of monosodium glutamate. The yield and productivity of gamma-aminobutyric acid might be significantly improved if the overexpressed GadB in E. coli cells can be excreted outside, where it can directly transforms monosodium glutamate to gamma-aminobutyric acid. In this study, GadB was fused to signal peptides TorA or PelB, respectively, and overexpressed in E. coli BL21(DE3). It was found that TorA could facilitate GadB secretion much better than PelB. Conditions for GadB secretion and gamma-aminobutyric acid production were optimized in E. coli BL21(DE3)/pET20b-torA-gadB, leading the secretion of more than half of the overexpressed GadB. Fed-batch fermentation for GadB expression and gamma-aminobutyric acid production of BL21(DE3)/pET20b-torA-gadB was sequentially performed in one fermenter; 264.4 and 313.1 g/L gamma-aminobutyric acid were obtained with addition of monosodium glutamate after 36 and 72 h, respectively. PMID:27549808

  12. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #081811

    SciTech Connect

    Taylor-Pashow, K.; Fink, S.

    2011-10-28

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.081811 qualification and 12 verification samples met all the requirements in the specification, with the possible exception of the geometric standard deviation for particle size. Two subsamples from the qualification sample were analyzed, giving results of 3.82 and 3.28, respectively, for the geometric standard deviation. The specification is {le}3.5. The results for both samples met the remaining particle size specifications, i.e. <10 vol% below 0.8 {mu}m and <1 vol% above 37 {mu}m. Filtration behavior of the current batch is expected to be near that of recent batches. SRNL recommends acceptance of this material. SRNL also recommends performing a statistical review of particle size data for the MST lots from this vendor to assess whether an improved material specification is appropriate.

  13. Fissile solubility and monosodium titanate loading tests

    SciTech Connect

    Hobbs, D.T.; Fleischman, S.D.

    1993-02-12

    The solubilities of plutonium and uranium have been determined for alkaline salt solutions having compositions which bound those which will be processed in the In-Tank Precipitation (ITP) process. Loadings of plutonium and uranium onto monosodium titanate (MST) have been determined at temperatures bounding those expected to occur during ITP and using a salt solution which was determined to have the maximum solubility for uranium and plutonium. Fissile loadings increase with decreasing amounts of MST in contact with the salt solutions saturated in plutonium and uranium. At MST concentrations bounding those which are planned for the ITP process, expressions for the maximum loadings (wt %) are determined to be 0.29 - 0.20x[MST] for plutonium and 1.8 - 0.29x[MST] for uranium, where [MST] is the concentration of MST in grams/liter. These expressions are valid over the range of MST concentrations from 0.05 to 0.51 g/L and temperatures of 17{degrees}--74{degrees}C. These loadings are below the individual infinitely safe limits for plutonium and uranium. Additional confirmatory experiments are planned to verify the effects of temperature and multiple contacts of the MST with fresh salt solution on the fissile loadings.

  14. Fissile solubility and monosodium titanate loading tests

    SciTech Connect

    Hobbs, D.T.; Fleischman, S.D.

    1993-02-12

    The solubilities of plutonium and uranium have been determined for alkaline salt solutions having compositions which bound those which will be processed in the In-Tank Precipitation (ITP) process. Loadings of plutonium and uranium onto monosodium titanate (MST) have been determined at temperatures bounding those expected to occur during ITP and using a salt solution which was determined to have the maximum solubility for uranium and plutonium. Fissile loadings increase with decreasing amounts of MST in contact with the salt solutions saturated in plutonium and uranium. At MST concentrations bounding those which are planned for the ITP process, expressions for the maximum loadings (wt %) are determined to be 0.29 - 0.20x[MST] for plutonium and 1.8 - 0.29x[MST] for uranium, where [MST] is the concentration of MST in grams/liter. These expressions are valid over the range of MST concentrations from 0.05 to 0.51 g/L and temperatures of 17[degrees]--74[degrees]C. These loadings are below the individual infinitely safe limits for plutonium and uranium. Additional confirmatory experiments are planned to verify the effects of temperature and multiple contacts of the MST with fresh salt solution on the fissile loadings.

  15. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #03031

    SciTech Connect

    Taylor-Pashow, K.

    2011-05-16

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot 030311 qualification and 9 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process. Harrell Industries is under contract with Savannah River Remediation to provide MST for use in the Actinide Removal Process (ARP). A 500-mL qualification sample for Lot 030311 was sent to the Savannah River National Laboratory (SRNL) to confirm the material meets the requirements specified in the purchase specification. The vendor is also obligated to send verification samples from {approx}10% or more of the pails of MST product for each lot (distributed roughly evenly through the entire lot of pails). For the verification of this lot, Harrell Industries sent 9 samples, one each from pails 1, 5, 15, 20, 25, 30, 40, 45, and 55 of 59 total pails.

  16. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #050411

    SciTech Connect

    Taylor-Pashow, K.

    2011-06-28

    Harrell Industries is under contract with Savannah River Remediation to provide Monosodium titanate (MST) for use in the Actinide Removal Process (ARP). A 500-mL qualification sample for Lot 050411 was sent to the Savannah River National Laboratory (SRNL) to confirm the material meets the requirements specified in the purchase specification. The vendor is also obligated to send verification samples from {approx}10% or more of the pails of MST product for each lot (distributed roughly evenly through the entire lot of pails). For the verification of this lot, Harrell Industries sent 12 samples, one each from pails No.1, 10, 20, 30, 40, 60, 70, 80, 90, 100, 110, and 120 of 120 total pails. MST for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot 050411 qualification and 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process.

  17. 40 CFR 721.3848 - Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-, monosodium salt. 721.3848 Section 721.3848 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3848 Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt. (a... glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt (PMN P-00-469; CAS No. 141321-68-8) is subject...

  18. 40 CFR 721.3848 - Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-, monosodium salt. 721.3848 Section 721.3848 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3848 Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt. (a... glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt (PMN P-00-469; CAS No. 141321-68-8) is subject...

  19. 40 CFR 721.3848 - Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-, monosodium salt. 721.3848 Section 721.3848 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3848 Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt. (a... glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt (PMN P-00-469; CAS No. 141321-68-8) is subject...

  20. 40 CFR 721.3848 - Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-, monosodium salt. 721.3848 Section 721.3848 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3848 Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt. (a... glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt (PMN P-00-469; CAS No. 141321-68-8) is subject...

  1. 40 CFR 721.3848 - Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-, monosodium salt. 721.3848 Section 721.3848 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3848 Glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt. (a... glycine, N-(carboxymethyl)-N-dodecyl-, monosodium salt (PMN P-00-469; CAS No. 141321-68-8) is subject...

  2. Effect of free dietary glutamate on gastric secretion in dogs.

    PubMed

    Zolotarev, Vasiliy; Khropycheva, Raisa; Uneyama, Hisayuki; Torii, Kunio

    2009-07-01

    The amino acid, L-glutamate, which is abundant in many foodstuffs, is a potent stimulator of gastric vagal afferents. The aim of the study was to evaluate a role of dietary glutamate in neuroendocrine control of gastric secretion of acid, pepsinogen, and fluid. In mongrel dogs with small gastric pouches surgically prepared according to Pavlov (vagally innervated) or Heidenhain (vagally decentralized), secretion in a pouch was induced by infusion into the main stomach of an amino acid-rich diet lacking glutamate (Elental) or the same diet supplemented with monosodium glutamate (MSG). Having no effect alone, MSG (100 mM) potentiated secretion induced by Elental both in Pavlov and Heidenhain models. In the Pavlov pouch, the effect of MSG was markedly reduced after i.v. injection of granisetron, an antagonist of 5-HT(3) receptors. In the Heidenhain model, MSG enhanced the stimulatory effect of pentagastrin (1 microg/kg, s.c.). In conclusion, dietary glutamate at doses not exceeding its common concentrations in foods substantially potentiates gastric phase secretion induced by stimulation of gastric mucosa with an amino acid-rich diet or by administration of pentagastrin. The effect of glutamate is partially mediated via serotonin secretion and stimulation of 5-HT(3) receptors. PMID:19686114

  3. Possible significance of adverse reactions to glutamate in humans.

    PubMed

    Reif-Lehrer, L

    1976-09-01

    Of those exposed to Chinese restaurant food, our studies indicate that 25% report adverse reactions (Chinese restaurant syndrome (CRS)), presumably to the mono-sodium glutamate (MSG) content. The possible significance of the symptoms is discussed in the light of the known neuroexcitatory activity of MSG. It is suggested that CRS may result from a "benign" inborn "error" of metabolism that is deserving of further study, particularly in individuals with certain other metabolic abnormalities or who are on certain types of drug therapy. PMID:782921

  4. 78 FR 65278 - Monosodium Glutamate From the People's Republic of China, and the Republic of Indonesia...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... Antidumping Duties; Countervailing Duties; Final Rule, 62 FR 27296, 27323 (May 19, 1997). \\8\\ See Antidumping... Procedures, 76 FR 39263 (July 6, 2011) for details of the Department's electronic filing requirements, which... Submission of Factual Information: Final Rule, 78 FR 21246 (April 10, 2013), which modified two...

  5. 78 FR 65269 - Monosodium Glutamate From the People's Republic of China and the Republic of Indonesia...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... Duties; Final Rule, 62 FR 27296, 27323 (May 19, 1997). \\7\\ See Antidumping and Countervailing Duty Proceedings: Electronic Filing Procedures; Administrative Protective Order Procedures, 76 FR 39263 (July 6... Information and Time Limits for Submission of Factual Information: Final Rule, 78 FR 21246 (April 10,...

  6. 78 FR 57881 - Monosodium Glutamate from China and Indonesia; Institution of Antidumping and Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... took effect on November 7, 2011. See 76 FR 61937 (Oct. 6, 2011) and the newly revised Commission's... investigations and Scheduling of Preliminary Phase Investigations AGENCY: United States International Trade... and commencement of preliminary phase antidumping and countervailing duty investigations Nos....

  7. 78 FR 74115 - Monosodium Glutamate From the People's Republic of China and the Republic of Indonesia...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... China and the Republic of Indonesia: Initiation of Countervailing Duty Investigations, 78 FR 65269... Administrative Determination Deadlines Pursuant to the Tariff Act of 1930, as Amended, 70 FR 24533 (May 10,...

  8. Disorders of glutamate metabolism.

    PubMed

    Kelly, A; Stanley, C A

    2001-01-01

    The significant role the amino acid glutamate assumes in a number of fundamental metabolic pathways is becoming better understood. As a central junction for interchange of amino nitrogen, glutamate facilitates both amino acid synthesis and degradation. In the liver, glutamate is the terminus for release of ammonia from amino acids, and the intrahepatic concentration of glutamate modulates the rate of ammonia detoxification into urea. In pancreatic beta-cells, oxidation of glutamate mediates amino acid-stimulated insulin secretion. In the central nervous system, glutamate serves as an excitatory neurotransmittor. Glutamate is also the precursor of the inhibitory neurotransmittor GABA, as well as glutamine, a potential mediator of hyperammonemic neurotoxicity. The recent identification of a novel form of congenital hyperinsulinism associated with asymptomatic hyperammonemia assigns glutamate oxidation by glutamate dehydrogenase a more important role than previously recognized in beta-cell insulin secretion and hepatic and CNS ammonia detoxification. Disruptions of glutamate metabolism have been implicated in other clinical disorders, such as pyridoxine-dependent seizures, confirming the importance of intact glutamate metabolism. This article will review glutamate metabolism and clinical disorders associated with disrupted glutamate metabolism. PMID:11754524

  9. 21 CFR 184.1521 - Monosodium phosphate derivatives of mono- and diglycerides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Monosodium phosphate derivatives of mono- and diglycerides. 184.1521 Section 184.1521 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1521 Monosodium...

  10. 21 CFR 184.1521 - Monosodium phosphate derivatives of mono- and diglycerides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Monosodium phosphate derivatives of mono- and diglycerides. 184.1521 Section 184.1521 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1521 Monosodium...

  11. Metabotropic glutamate receptors inhibit microglial glutamate release

    PubMed Central

    McMullan, Stephen M; Phanavanh, Bounleut; Guo Li, Gary; Barger, Steven W

    2012-01-01

    Pro-inflammatory stimuli evoke an export of glutamate from microglia that is sufficient to contribute to excitotoxicity in neighbouring neurons. Since microglia also express various glutamate receptors themselves, we were interested in the potential feedback of glutamate on this system. Several agonists of mGluRs (metabotropic glutamate receptors) were applied to primary rat microglia, and the export of glutamate into their culture medium was evoked by LPS (lipopolysaccharide). Agonists of group-II and -III mGluR ACPD [(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid] and L-AP4 [L-(+)-2-amino-4-phosphonobutyric acid] were both capable of completely blocking the glutamate export without interfering with the production of NO (nitric oxide); the group-I agonist tADA (trans-azetidine-2,4-dicarboxylic acid) was ineffective. Consistent with the possibility of feedback, inhibition of mGluR by MSPG [(R,S)-α-2-methyl-4sulfonophenylglycine] potentiated glutamate export. As the group-II and -III mGluR are coupled to Gαi-containing G-proteins and the inhibition of adenylate cyclase, we explored the role of cAMP in this effect. Inhibition of cAMP-dependent protein kinase [also known as protein kinase A (PKA)] by H89 mimicked the effect of ACPD, and the mGluR agonist had its actions reversed by artificially sustaining cAMP through the PDE (phosphodiesterase) inhibitor IBMX (isobutylmethylxanthine) or the cAMP mimetic dbcAMP (dibutyryl cAMP). These data indicate that mGluR activation attenuates a potentially neurotoxic export of glutamate from activated microglia and implicate cAMP as a contributor to this aspect of microglial action. PMID:22770428

  12. SLC1 Glutamate Transporters

    PubMed Central

    Grewer, Christof; Gameiro, Armanda; Rauen, Thomas

    2014-01-01

    The plasma membrane transporters for the neurotransmitter glutamate belong to the solute carrier 1 (SLC1) family. They are secondary active transporters, taking up glutamate into the cell against a substantial concentration gradient. The driving force for concentrative uptake is provided by the cotransport of Na+ ions and the countertransport of one K+ in a step independent of the glutamate translocation step. Due to eletrogenicity of transport, the transmembrane potential can also act as a driving force. Glutamate transporters are expressed in many tissues, but are of particular importance in the brain, where they contribute to the termination of excitatory neurotransmission. Glutamate transporters can also run in reverse, resulting in glutamate release from cells. Due to these important physiological functions, glutamate transporter expression and, therefore, the transport rate, are tightly regulated. This review summarizes recent literature on the functional and biophysical properties, structure-function relationships, regulation, physiological significance, and pharmacology of glutamate transporters. Particular emphasis is on the insight from rapid kinetic and electrophysiological studies, transcriptional regulation of transporter expression, and reverse transport and its importance for pathophysiological glutamate release under ischemic conditions. PMID:24240778

  13. Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate.

    PubMed

    Elvington, Mark C; Taylor-Pashow, Kathryn M L; Tosten, Michael H; Hobbs, David T

    2016-01-01

    This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150 nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m(2)g(-1), which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide. PMID:26967828

  14. Glutamate and Neurodegenerative Disease

    NASA Astrophysics Data System (ADS)

    Schaeffer, Eric; Duplantier, Allen

    As the main excitatory neurotransmitter in the mammalian central nervous system, glutamate is critically involved in most aspects of CNS function. Given this critical role, it is not surprising that glutamatergic dysfunction is associated with many CNS disorders. In this chapter, we review the literature that links aberrant glutamate neurotransmission with CNS pathology, with a focus on neurodegenerative diseases. The biology and pharmacology of the various glutamate receptor families are discussed, along with data which links these receptors with neurodegenerative conditions. In addition, we review progress that has been made in developing small molecule modulators of glutamate receptors and transporters, and describe how these compounds have helped us understand the complex pharmacology of glutamate in normal CNS function, as well as their potential for the treatment of neurodegenerative diseases.

  15. Glutamate release from platelets: exocytosis versus glutamate transporter reversal.

    PubMed

    Kasatkina, Ludmila A; Borisova, Tatiana A

    2013-11-01

    Platelets express neuronal and glial glutamate transporters EAAT 1-3 in the plasma membrane and vesicular glutamate transporters VGLUT 1,2 in the membrane of secretory granules. This study is focused on the assessment of non-exocytotic glutamate release, that is, the unstimulated release, heteroexchange and glutamate transporter reversal in platelets. Using the glutamate dehydrogenase assay, the absence of unstimulated release of endogenous glutamate from platelets was demonstrated, even after inhibition of glutamate transporters and cytoplasmic enzyme glutamine synthetase by dl-threo-β-benzyloxyaspartate and methionine sulfoximine, respectively. Depolarization of the plasma membrane by exposure to elevated [K(+)] did not induce the release of glutamate from platelets that was shown using the glutamate dehydrogenase assay and radiolabeled l-[(14)C]glutamate. Glutamate efflux by means of heteroexchange with transportable inhibitor of glutamate transporters dl-threo-β-hydroxyaspartate (dl-THA) was not observed. Furthermore, the protonophore cyanide-p-trifluoromethoxyphenyl-hydrazon (FCCP) and inhibitor of V-type H(+)-ATPase bafilomycin A1 also failed to stimulate the release of glutamate from platelets. However, exocytotic release of glutamate from secretory granules in response to thrombin stimulation was not prevented by elevated [K(+)], dl-THA, FCCP and bafilomycin A1. In contrast to nerve terminals, platelets cannot release glutamate in a non-exocytotic manner. Heteroexchange, transporter-mediated and unstimulated release of glutamate are not inherent to platelets. Therefore, platelets may be used as a peripheral marker/model for the analysis of glutamate uptake by brain nerve terminals only (direct function of transporters), whereas the mechanisms of glutamate release are different in platelets and nerve terminals. Glutamate is released by platelets exclusively by means of exocytosis. Also, reverse function of vesicular glutamate transporters of platelets is

  16. Biosynthetic preparation of L-(/sup 13/C)- and (/sup 15/N)glutamate by Brevibacterium flavum

    SciTech Connect

    Walker, T.E.; London, R.E.

    1987-01-01

    The biosynthesis of isotopically labeled L-glutamic acid by the microorganism Brevibacterium flavum was studied with a variety of carbon-13-enriched precursors. The purpose of this study was twofold: (i) to develop techniques for the efficient preparation of labeled L-glutamate with a variety of useful labeling patterns which can be used for other metabolic studies, and (ii) to better understand the metabolic events leading to label scrambling in these strains. B. flavum, which is used commercially for the production of monosodium glutamate, has the capability of utilizing glucose or acetate as a sole carbon source, and important criterion from the standpoint of developing labeling strategies. Unfortunately, singly labeled glucose precursors lead to excessive isotopic dilution which reduces their usefulness. Studies with (3-/sup 13/C)pyruvate indicate that this problem can in principle be overcome by using labeled three-carbon precursors; however, conditions could not be found which would lead to an acceptable yield of isotopically labeled L-glutamate. In contrast, (1-/sup 13/C)- or (2-/sup 13/C)acetate provides relatively inexpensive, readily available precursors for the production of selectively labeled, high enriched L-glutamate. The preparation of L-(/sup 15/N)glutamate from (/sup 15/N)ammonium sulfate was carried out and is a very effective labeling strategy. Analysis of the isotopic distribution in labeled glutamate provides details about the metabolic pathways in these interesting organisms.

  17. Evaluation of genotoxic effects of five flavour enhancers (glutamates) on the root meristem cells of Allium cepa.

    PubMed

    Türkoğlu, Şifa

    2015-09-01

    The effects of different treatments with flavour enhancers monosodium glutamate, monopotassium glutamate, calcium diglutamate, monoammonium glutamate, and magnesium diglutamate on the cytology, DNA content, and interphase nuclear volume (INV) of A. cepa were investigated. Three concentrations of these additives - 20, 40, and 60 ppm - were applied for 6, 12, and 24 h. All the concentrations of these chemicals showed an inhibitory effect on cell division in root tips of A. cepa and caused a decrease in mitotic index values. Additionally, all the treatments changed the frequency of mitotic phases when compared with the control groups. These compounds increased chromosome abnormalities, among them are micronuclei, c-mitosis, anaphase bridges, stickiness, binucleus, laggards, and breaks. The nuclear DNA content and INV decreased when compared with control groups. PMID:23377115

  18. LEACHING OF TITANIUM FROM MONOSODIUM TITANATE AND MODIFIED MST

    SciTech Connect

    Taylor-Pashow, K.; Fondeur, F.; Fink, S.

    2012-08-01

    Analysis of a fouled coalescer and pre-filters from Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) operations showed evidence of Ti containing solids. Based on these results a series of tests were planned to examine the extent of Ti leaching from monosodium titanate (MST) and modified monosodium titanate (mMST) in various solutions. The solutions tested included a series of salt solutions with varying free hydroxide concentrations, two sodium hydroxide concentrations, 9 wt % and 15 wt %, nitric and oxalic acid solutions. Overall, the amount of Ti leached from the MST and mMST was much greater in the acid solutions compared to the sodium hydroxide or salt solutions, which is consistent with the expected trend. The leaching data also showed that increasing hydroxide concentration, whether pure NaOH solution used for filter cleaning in ARP or the waste salt solution, increased the amount of Ti leached from both the MST and mMST. For the respective nominal contact times with the MST solids - for filter cleaning or the normal filter operation, the dissolved Ti concentrations are comparable suggesting either cause may contribute to the increased Ti fouling on the MCU coalescers. Tests showed that Ti containing solids could be precipitated from solution after the addition of scrub acid and a decrease in temperature similar to expected in MCU operations. FTIR analysis of these solids showed some similarity to the solids observed on the fouled coalescer and pre-filters. Although only a cursory study, this information suggests that the practice of increasing free hydroxide in feed solutions to MCU as a mitigation to aluminosilicate formation may be offset by the impact of formation of Ti solids in the overall process. Additional consideration of this finding from MCU and SWPF operation is warranted.

  19. Non-sterilized fermentative co-production of poly(γ-glutamic acid) and fibrinolytic enzyme by a thermophilic Bacillus subtilis GXA-28.

    PubMed

    Zeng, Wei; Li, Wei; Shu, Lin; Yi, Juyang; Chen, Guiguang; Liang, Zhiqun

    2013-08-01

    Poly(γ-glutamic acid), as a naturally occurring homopolymer, is widely used in industry, agriculture, food and medicine. Fibrinolytic enzyme has a great potential for the prevention and/or treatment of vascular diseases caused by fibrin clots. Co-production of γ-PGA and fibrinolytic enzyme by Bacillus subtilis GXA-28 (CCTCC M 2012347) from soybean residue using cane molasses and monosodium glutamate waste liquor under sterilized and non-sterilized condition were investigated. It was observed that total sugar from cane molasses of 3% (w/w) and glutamate from monosodium glutamate waste liquor of 2% (w/w) were favorable for γ-PGA and fibrinolytic enzyme co-production at pH 7.0 and 45°C. Based on the optimal medium, the γ-PGA and fibrinolytic activity reached 103.5 g/kg-substrates at 22 h and 986 U/g-substrates at 24h under non-sterilized condition, respectively. To our knowledge, the yield of γ-PGA was highest in all reported literatures. PMID:23725975

  20. Adsorption of biometals to monosodium titanate in biological environments

    SciTech Connect

    HOBBS, D.T.; MESSER, R. L. W.; LEWIS, J. B.; CLICK, D. R. LOCKWOOD, P. E.; WATAHA, J. C.

    2005-06-06

    Monosodium titanate (MST) is an inorganic sorbent/ion exchanger developed for the removal of radionuclides from nuclear wastes. We investigated the ability of MST to bind Cd(II), Hg(II), or Au(III) to establish the utility of MST for applications in environmental decontamination or medical therapy (drug delivery). Adsorption isotherms for MST were determined at pH 7-7.5 in water or phosphate-buffered saline. The extent of metal binding was determined spectroscopically by measuring the concentrations of the metals in solution before and after contact with the MST. Cytotoxic responses to MST were assessed using THP1 monocytes and succinate dehydrogenase activity. Monocytic activation by MST was assessed by TNF{alpha} secretion (ELISA) with or without lipopolysaccharide (LPS) activation. MST sorbed Cd(II), Hg(II), and Au(III) under conditions similar to that in physiological systems. MST exhibited the highest affinity for Cd(II) followed by Hg(II) and Au (III). MST (up to 100 mg/L) exhibited only minor (< 25% suppression of succinate dehydrogenase) cytotoxicity and did not trigger TNF{alpha} secretion nor modulate LPS-induced TNF{alpha} secretion from monocytes. MST exhibits high affinity for biometals with no significant biological liabilities in these introductory studies. MST deserves further scrutiny as a substance with the capacity to decontaminate biological environments or deliver metals in a controlled fashion.

  1. Adsorption of biometals to monosodium titanate in biological environments.

    PubMed

    Hobbs, D T; Messer, R L W; Lewis, J B; Click, D R; Lockwood, P E; Wataha, J C

    2006-08-01

    Monosodium titanate (MST) is an inorganic sorbent/ion exchanger developed for the removal of radionuclides from nuclear wastes. We investigated the ability of MST to bind Cd(II), Hg(II), Au(III), or the Au-organic compound auranofin to establish the utility of MST for applications in environmental decontamination or medical therapy (drug delivery). Adsorption isotherms for MST were determined at pH 7-7.5 in water or phosphate-buffered saline. The extent of metal binding was determined spectroscopically by measuring the concentrations of the metals in solution before and after contact with the MST. Cytotoxic responses to MST were assessed using THP1 monocytes and succinate dehydrogenase activity. Monocytic activation by MST was assessed by TNFalpha secretion (ELISA) with or without lipopolysaccharide (LPS) activation. MST adsorbed Cd(II), Hg(II), and Au(III) under conditions similar to those in physiological systems. MST exhibited the highest affinity for Cd(II) followed by Hg(II) and Au (III). MST (up to 100 mg/L) exhibited only minor (<25% suppression of succinate dehydrogenase) cytotoxicity and did not trigger TNFalpha secretion nor modulate LPS-induced TNFalpha secretion from monocytes. MST exhibits high affinity for biometals with no significant biological liabilities in these introductory studies. MST deserves further scrutiny as a substance with the capacity to decontaminate biological environments or deliver metals or metal compounds for therapeutic applications. PMID:16362965

  2. Monosodium Urate Crystal-Induced Chondrocyte Death via Autophagic Process

    PubMed Central

    Hwang, Hyun Sook; Yang, Chung Mi; Park, Su Jin; Kim, Hyun Ah

    2015-01-01

    Monosodium urate (MSU) crystals, which are highly precipitated in the joint cartilage, increase the production of cartilage-degrading enzymes and pro-inflammatory mediators in cartilage, thereby leading to gouty inflammation and joint damage. In this study, we investigated the effect of MSU crystals on the viability of human articular chondrocytes and the mechanism of MSU crystal-induced chondrocyte death. MSU crystals significantly decreased the viability of primary chondrocytes in a time- and dose-dependent manner. DNA fragmentation was observed in a culture medium of MSU crystal-treated chondrocytes, but not in cell lysates. MSU crystals did not activate caspase-3, a marker of apoptosis, compared with actinomycin D and TNF-α-treated cells. MSU crystals did not directly affect the expression of endoplasmic reticulum (ER) stress markers at the mRNA and protein levels. However, MSU crystals significantly increased the LC3-II level in a time-dependent manner, indicating autophagy activation. Moreover, MSU crystal-induced autophagy and subsequent chondrocyte death were significantly inhibited by 3-methyladenine, a blocker of autophagosomes formation. MSU crystals activated autophagy via inhibition of phosporylation of the Akt/mTOR signaling pathway. These results demonstrate that MSU crystals may cause the death of chondrocytes through the activation of the autophagic process rather than apoptosis or ER stress. PMID:26670233

  3. Synthesis and characterization of monosodium urate (MSU) nano particles

    NASA Astrophysics Data System (ADS)

    Tank, Nirali S.; Rathod, K. R.; Parekh, B. B.; Parikh, K. D.; Joshi, M. J.

    2016-05-01

    In Gout the deposition of crystals of Monosodium Urate (MSU) in various connective tissues and joints occurs, which is very painful with immflamation. The deposition likely to begin with nano particles form and expected to grow in to micro-paricles and hence it is important to synthesize and characrterize MSU nano-particles. The MSU nano particles were synthesized by wet chemical method using NaOH and uric acid (C5H4N4O3) and then characterized by powder XRD, TEM, FT-IR and thermal analysis. From the powder XRD the triclinic structure was found and 40 nm average particle size was estimated by using Scherrer's formula. From TEM the particle size was found to be in the range of 20 to 60 nm. The FT-IR spectrum for the MSU nano particles confirmed the presence of O-H stretching, N-H stretching, N-H rocking, C = O, C = C Enol or Keto and C = N vibrations. The thermal analysis was carried out from room temperature to 900°C. With comparison to the bulk MSU the thermal stability of MSU nano particles was slightly higher and 1.5 water molecules were found to be associated with MSU nano particles. Present results are compared with the bulk MSU.

  4. 21 CFR 582.4521 - Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4521 Section 582.4521 Food and... Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Monosodium phosphate derivatives of mono- and diglycerides of edible fats...

  5. 21 CFR 582.4521 - Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4521 Section 582.4521 Food and... Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Monosodium phosphate derivatives of mono- and diglycerides of edible fats...

  6. 21 CFR 582.4521 - Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4521 Section 582.4521 Food and... Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Monosodium phosphate derivatives of mono- and diglycerides of edible fats...

  7. 21 CFR 582.4521 - Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4521 Section 582.4521 Food and... Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Monosodium phosphate derivatives of mono- and diglycerides of edible fats...

  8. 21 CFR 582.4521 - Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4521 Section 582.4521 Food and... Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Monosodium phosphate derivatives of mono- and diglycerides of edible fats...

  9. New insights into the bonding arrangements of L- and D-glutamates from solid state 17O NMR

    NASA Astrophysics Data System (ADS)

    Lemaitre, V.; Pike, K. J.; Watts, A.; Anupold, T.; Samoson, A.; Smith, M. E.; Dupree, R.

    2003-03-01

    Magic angle spinning (MAS) from L- and D-glutamic acid-HCl at 14.1 T produces highly structured and very similar NMR spectra. Lines from all 4 oxygen sites are readily distinguished and assigned. These 17O NMR spectra are very different from the previously reported 17O spectrum of the D, L-form presumably because that was a racemic crystal. 17O NMR from L-monosodium glutamate-HCl is very different again requiring the application of double angle rotation and 3 quantum MAS NMR to provide resolution of 5 different sites. Hence high resolution 17O solid state NMR techniques offer possible new insight into biochemical bonding processes.

  10. Gamma-aminobutyric acid production using immobilized glutamate decarboxylase followed by downstream processing with cation exchange chromatography.

    PubMed

    Lee, Seungwoon; Ahn, Jungoh; Kim, Yeon-Gu; Jung, Joon-Ki; Lee, Hongweon; Lee, Eun Gyo

    2013-01-01

    We have developed a gamma-aminobutyric acid (GABA) production technique using his-tag mediated immobilization of Escherichia coli-derived glutamate decarboxylase (GAD), an enzyme that catalyzes the conversion of glutamate to GABA. The GAD was obtained at 1.43 g/L from GAD-overexpressed E. coli fermentation and consisted of 59.7% monomer, 29.2% dimer and 2.3% tetramer with a 97.6% soluble form of the total GAD. The harvested GAD was immobilized to metal affinity gel with an immobilization yield of 92%. Based on an investigation of specific enzyme activity and reaction characteristics, glutamic acid (GA) was chosen over monosodium glutamate (MSG) as a substrate for immobilized GAD, resulting in conversion of 2.17 M GABA in a 1 L reactor within 100 min. The immobilized enzymes retained 58.1% of their initial activities after ten consecutive uses. By using cation exchange chromatography followed by enzymatic conversion, GABA was separated from the residual substrate and leached GAD. As a consequence, the glutamic acid was mostly removed with no detectable GAD, while 91.2% of GABA was yielded in the purification step. PMID:23322022

  11. 75 FR 40824 - Monosodium methanearsonate (MSMA); Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... Federal Register notice (75 FR 17733; FRL-8819-2)announcing the Agency's receipt of the requests for... April 7, 2010 (75 FR 17733) (FRL-8819-2). The comment period closed on May 7, 2010. VI. Provisions for... AGENCY Monosodium methanearsonate (MSMA); Cancellation Order for Certain Pesticide Registrations...

  12. 21 CFR 184.1521 - Monosodium phosphate derivatives of mono- and diglycerides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Monosodium phosphate derivatives of mono- and diglycerides. 184.1521 Section 184.1521 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  13. 21 CFR 184.1521 - Monosodium phosphate derivatives of mono- and diglycerides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Monosodium phosphate derivatives of mono- and diglycerides. 184.1521 Section 184.1521 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing...

  14. Growth and adhesion properties of monosodium urate monohydrate (MSU) crystals

    NASA Astrophysics Data System (ADS)

    Perrin, Clare M.

    The presence of monosodium urate monohydrate (MSU) crystals in the synovial fluid has long been associated with the joint disease gout. To elucidate the molecular level growth mechanism and adhesive properties of MSU crystals, atomic force microscopy (AFM), scanning electron microscopy, and dynamic light scattering (DLS) techniques were employed in the characterization of the (010) and (1-10) faces of MSU, as well as physiologically relevant solutions supersaturated with urate. Topographical AFM imaging of both MSU (010) and (1-10) revealed the presence of crystalline layers of urate arranged into v-shaped features of varying height. Growth rates were measured for both monolayers (elementary steps) and multiple layers (macrosteps) on both crystal faces under a wide range of urate supersaturation in physiologically relevant solutions. Step velocities for monolayers and multiple layers displayed a second order polynomial dependence on urate supersaturation on MSU (010) and (1-10), with step velocities on (1-10) generally half of those measured on MSU (010) in corresponding growth conditions. Perpendicular step velocities on MSU (010) were obtained and also showed a second order polynomial dependence of step velocity with respect to urate supersaturation, which implies a 2D-island nucleation growth mechanism for MSU (010). Extensive topographical imaging of MSU (010) showed island adsorption from urate growth solutions under all urate solution concentrations investigated, lending further support for the determined growth mechanism. Island sizes derived from DLS experiments on growth solutions were in agreement with those measured on MSU (010) topographical images. Chemical force microscopy (CFM) was utilized to characterize the adhesive properties of MSU (010) and (1-10). AFM probes functionalized with amino acid derivatives and bio-macromolecules found in the synovial fluid were brought into contact with both crystal faces and adhesion forces were tabulated into

  15. Metabotropic Glutamate Receptors

    PubMed Central

    Dillon, James; Franks, Christopher J.; Murray, Caitriona; Edwards, Richard J.; Calahorro, Fernando; Ishihara, Takeshi; Katsura, Isao; Holden-Dye, Lindy; O'Connor, Vincent

    2015-01-01

    Glutamatergic neurotransmission is evolutionarily conserved across animal phyla. A major class of glutamate receptors consists of the metabotropic glutamate receptors (mGluRs). In C. elegans, three mGluR genes, mgl-1, mgl-2, and mgl-3, are organized into three subgroups, similar to their mammalian counterparts. Cellular reporters identified expression of the mgls in the nervous system of C. elegans and overlapping expression in the pharyngeal microcircuit that controls pharyngeal muscle activity and feeding behavior. The overlapping expression of mgls within this circuit allowed the investigation of receptor signaling per se and in the context of receptor interactions within a neural network that regulates feeding. We utilized the pharmacological manipulation of neuronally regulated pumping of the pharyngeal muscle in the wild-type and mutants to investigate MGL function. This defined a net mgl-1-dependent inhibition of pharyngeal pumping that is modulated by mgl-3 excitation. Optogenetic activation of the pharyngeal glutamatergic inputs combined with electrophysiological recordings from the isolated pharyngeal preparations provided further evidence for a presynaptic mgl-1-dependent regulation of pharyngeal activity. Analysis of mgl-1, mgl-2, and mgl-3 mutant feeding behavior in the intact organism after acute food removal identified a significant role for mgl-1 in the regulation of an adaptive feeding response. Our data describe the molecular and cellular organization of mgl-1, mgl-2, and mgl-3. Pharmacological analysis identified that, in these paradigms, mgl-1 and mgl-3, but not mgl-2, can modulate the pharyngeal microcircuit. Behavioral analysis identified mgl-1 as a significant determinant of the glutamate-dependent modulation of feeding, further highlighting the significance of mGluRs in complex C. elegans behavior. PMID:25869139

  16. Pivotal Enzyme in Glutamate Metabolism of Poly-γ-Glutamate-Producing Microbes

    PubMed Central

    Ashiuchi, Makoto; Yamamoto, Takashi; Kamei, Tohru

    2013-01-01

    The extremely halophilic archaeon Natrialba aegyptiaca secretes the L-homo type of poly-γ-glutamate (PGA) as an extremolyte. We examined the enzymes involved in glutamate metabolism and verified the presence of L-glutamate dehydrogenases, L-aspartate aminotransferase, and L-glutamate synthase. However, neither glutamate racemase nor D-amino acid aminotransferase activity was detected, suggesting the absence of sources of D-glutamate. In contrast, D-glutamate-rich PGA producers mostly possess such intracellular sources of D-glutamate. The results of our present study indicate that the D-glutamate-anabolic enzyme “glutamate racemase” is pivotal in the biosynthesis of PGA. PMID:25371338

  17. Glutamic acid as anticancer agent: An overview

    PubMed Central

    Dutta, Satyajit; Ray, Supratim; Nagarajan, K.

    2013-01-01

    The objective of the article is to highlight various roles of glutamic acid like endogenic anticancer agent, conjugates to anticancer agents, and derivatives of glutamic acid as possible anticancer agents. Besides these emphases are given especially for two endogenous derivatives of glutamic acid such as glutamine and glutamate. Glutamine is a derivative of glutamic acid and is formed in the body from glutamic acid and ammonia in an energy requiring reaction catalyzed by glutamine synthase. It also possesses anticancer activity. So the transportation and metabolism of glutamine are also discussed for better understanding the role of glutamic acid. Glutamates are the carboxylate anions and salts of glutamic acid. Here the roles of various enzymes required for the metabolism of glutamates are also discussed. PMID:24227952

  18. Computational Studies of Glutamate Transporters

    PubMed Central

    Setiadi, Jeffry; Heinzelmann, Germano; Kuyucak, Serdar

    2015-01-01

    Glutamate is the major excitatory neurotransmitter in the human brain whose binding to receptors on neurons excites them while excess glutamate are removed from synapses via transporter proteins. Determination of the crystal structures of bacterial aspartate transporters has paved the way for computational investigation of their function and dynamics at the molecular level. Here, we review molecular dynamics and free energy calculation methods used in these computational studies and discuss the recent applications to glutamate transporters. The focus of the review is on the insights gained on the transport mechanism through computational methods, which otherwise is not directly accessible by experimental probes. Recent efforts to model the mammalian glutamate and other amino acid transporters, whose crystal structures have not been solved yet, are included in the review. PMID:26569328

  19. Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid.

    PubMed

    Huang, Yan; Su, Lingqia; Wu, Jing

    2016-01-01

    Glutamate decarboxylase (GAD) catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA). In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP)-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V) activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C). Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C), superior thermostability (2.8-fold greater than that of GAD-C), and higher kcat/Km (1.6-fold higher than that of GAD-C). Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG) to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA. PMID:27438707

  20. Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid

    PubMed Central

    Huang, Yan; Su, Lingqia; Wu, Jing

    2016-01-01

    Glutamate decarboxylase (GAD) catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA). In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP)-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V) activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C). Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C), superior thermostability (2.8-fold greater than that of GAD-C), and higher kcat/Km (1.6-fold higher than that of GAD-C). Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG) to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA. PMID:27438707

  1. Glutamate receptors at atomic resolution

    SciTech Connect

    Mayer, Mark L.

    2010-12-03

    At synapses throughout the brain and spinal cord, the amino-acid glutamate is the major excitatory neurotransmitter. During evolution, a family of glutamate-receptor ion channels seems to have been assembled from a kit consisting of discrete ligand-binding, ion-channel, modulatory and cytoplasmic domains. Crystallographic studies that exploit this unique architecture have greatly aided structural analysis of the ligand-binding core, but the results also pose a formidable challenge, namely that of resolving the allosteric mechanisms by which individual domains communicate and function in an intact receptor.

  2. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #s 46000606120, 46000722120, AND 46000808120

    SciTech Connect

    Taylor-Pashow, K.

    2012-10-08

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #s 46000706120, 46000722120, and 460008081120 qualification and verification samples met each of the selected specification requirements that were tested with the exception of a few pails being marginally below the lower weight percent solids limit. These deviations from the specifications are viewed as negligible since the corresponding density of the slurries indicates no appreciable shortage of MST solids. Therefore, SRNL recommends acceptance and use of these pails.

  3. SORPTION BEHAVIOR OF MONOSODIUM TITANATE AND AMORPHOUS PEROXOTITANATE MATERIALS UNDER WEAKLY ACIDIC CONDITIONS

    SciTech Connect

    Hobbs, D.; Elvington, M.; Click, D.

    2009-11-11

    Inorganic, titanate-based sorbents are tested with respect to adsorption of a variety of sorbates under weakly acidic conditions (pH 3). Specifically, monosodium titanate (MST) and amorphous peroxotitanate (APT) sorption characteristics are initially probed through a screening process consisting of a pair of mixed metal solutions containing a total of 29 sorbates including alkali metals, alkaline earth metals, transition metals, metalloids and nonmetals. MST and APT sorption characteristics are further analyzed individually with chromium(III) and cadmium(II) using a batch method at ambient laboratory temperature, varying concentrations of the sorbents and sorbates and contact times. Maximum sorbate loadings are obtained from the respective adsorption isotherms.

  4. Glutamate in peripheral organs: Biology and pharmacology.

    PubMed

    Du, Jie; Li, Xiao-Hui; Li, Yuan-Jian

    2016-08-01

    Glutamate is a versatile molecule existing in both the central nervous system and peripheral organs. Previous studies have mainly focussed on the biological effect of glutamate in the brain. Recently, abundant evidence has demonstrated that glutamate also participates in the regulation of physiopathological functions in peripheral tissues, including the lung, kidney, liver, heart, stomach and immune system, where the glutamate/glutamate receptor/glutamate transporter system plays an important role in the pathogenesis of certain diseases, such as myocardial ischaemia/reperfusion injury and acute gastric mucosa injury. All these findings provide new insight into the biology and pharmacology of glutamate and suggest a potential therapeutic role of glutamate in non-neurological diseases. PMID:27164423

  5. 21 CFR 182.1045 - Glutamic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Glutamic acid. 182.1045 Section 182.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1045 Glutamic acid. (a) Product. Glutamic acid. (b) (c) Limitations, restrictions, or explanation....

  6. 21 CFR 182.1045 - Glutamic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Glutamic acid. 182.1045 Section 182.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1045 Glutamic acid. (a) Product. Glutamic acid. (b) (c) Limitations, restrictions, or explanation....

  7. 21 CFR 182.1045 - Glutamic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glutamic acid. 182.1045 Section 182.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1045 Glutamic acid. (a) Product. Glutamic acid. (b) (c) Limitations, restrictions, or explanation....

  8. 21 CFR 182.1045 - Glutamic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Glutamic acid. 182.1045 Section 182.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1045 Glutamic acid. (a) Product. Glutamic acid. (b) (c) Limitations, restrictions, or explanation....

  9. 21 CFR 182.1045 - Glutamic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Glutamic acid. 182.1045 Section 182.1045 Food and... GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1045 Glutamic acid. (a) Product. Glutamic acid. (b) (c) Limitations, restrictions, or explanation. This substance is generally recognized...

  10. Modes of glutamate receptor gating

    PubMed Central

    Popescu, Gabriela K

    2012-01-01

    Abstract The time course of excitatory synaptic currents, the major means of fast communication between neurons of the central nervous system, is encoded in the dynamic behaviour of post-synaptic glutamate-activated channels. First-pass attempts to explain the glutamate-elicited currents with mathematical models produced reaction mechanisms that included only the most basic functionally defined states: resting vs. liganded, closed vs. open, responsive vs. desensitized. In contrast, single-molecule observations afforded by the patch-clamp technique revealed an unanticipated kinetic multiplicity of transitions: from microseconds-lasting flickers to minutes-long modes. How these kinetically defined events impact the shape of the synaptic response, how they relate to rearrangements in receptor structure, and whether and how they are physiologically controlled represent currently active research directions. Modal gating, which refers to the slowest, least frequently observed ion-channel transitions, has been demonstrated for representatives of all ion channel families. However, reaction schemes have been largely confined to the short- and medium-range time scales. For glutamate receptors as well, modal gating has only recently come under rigorous scrutiny. This article reviews the evidence for modal gating of glutamate receptors and the still developing hypotheses about the mechanism(s) by which modal shifts occur and the ways in which they may impact the time course of synaptic transmission. PMID:22106181

  11. Fluorescence imaging of glutamate release in neurons

    SciTech Connect

    Wang, Ziqiang; Yeung, Edward S.

    1999-12-01

    A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with charge-coupled device (CCD) imaging is down to {mu}M levels of glutamate with reasonable response time ({approx}30 s). The standard glutamate test shows a linear response over 3 orders of magnitude, from {mu}M to 0.1 mM range. The in vitro monitoring of glutamate release from cultured neuron cells demonstrated excellent spatial and temporal resolution. (c) 1999 Society for Applied Spectroscopy.

  12. Nonvesicular Release of Glutamate by Glial xCT Transporters Suppresses Glutamate Receptor Clustering In Vivo

    PubMed Central

    Augustin, Hrvoje; Grosjean, Yael; Chen, Kaiyun; Sheng, Qi; Featherstone, David E.

    2008-01-01

    We hypothesized that cystine/glutamate transporters (xCTs) might be critical regulators of ambient extracellular glutamate levels in the nervous system and that misregulation of this glutamate pool might have important neurophysiological and/or behavioral consequences. To test this idea, we identified and functionally characterized a novel Drosophila xCT gene, which we subsequently named “genderblind” (gb). Genderblind is expressed in a previously overlooked subset of peripheral and central glia. Genetic elimination of gb causes a 50% reduction in extracellular glutamate concentration, demonstrating that xCT transporters are important regulators of extracellular glutamate. Consistent with previous studies showing that extracellular glutamate regulates postsynaptic glutamate receptor clustering, gb mutants show a large (200–300%) increase in the number of postsynaptic glutamate receptors. This increase in postsynaptic receptor abundance is not accompanied by other obvious synaptic changes and is completely rescued when synapses are cultured in wild-type levels of glutamate. Additional in situ pharmacology suggests that glutamate-mediated suppression of glutamate receptor clustering depends on receptor desensitization. Together, our results suggest that (1) xCT transporters are critical for regulation of ambient extracellular glutamate in vivo; (2) ambient extracellular glutamate maintains some receptors constitutively desensitized in vivo; and (3) constitutive desensitization of ionotropic glutamate receptors suppresses their ability to cluster at synapses. PMID:17202478

  13. Ligands for Ionotropic Glutamate Receptors

    NASA Astrophysics Data System (ADS)

    Swanson, Geoffrey T.; Sakai, Ryuichi

    Marine-derived small molecules and peptides have played a central role in elaborating pharmacological specificities and neuronal functions of mammalian ionotropic glutamate receptors (iGluRs), the primary mediators of excitatory syn-aptic transmission in the central nervous system (CNS). As well, the pathological sequelae elicited by one class of compounds (the kainoids) constitute a widely-used animal model for human mesial temporal lobe epilepsy (mTLE). New and existing molecules could prove useful as lead compounds for the development of therapeutics for neuropathologies that have aberrant glutamatergic signaling as a central component. In this chapter we discuss natural source origins and pharmacological activities of those marine compounds that target ionotropic glutamate receptors.

  14. Physiological roles of dietary glutamate signaling via gut-brain axis due to efficient digestion and absorption.

    PubMed

    Torii, Kunio; Uneyama, Hisayuki; Nakamura, Eiji

    2013-04-01

    Dietary glutamate (Glu) stimulates to evoke the umami taste, one of the five basic tastes, enhancing food palatability. But it is also the main gut energy source for the absorption and metabolism for each nutrient, thus, only a trace amount of Glu reaches the general circulation. Recently, we demonstrated a unique gut sensing system for free Glu (glutamate signaling). Glu is the only nutrient among amino acids, sugars and electrolytes that activates rat gastric vagal afferents from the luminal side specifically via metabotropic Glu receptors type 1 on mucosal cells releasing mucin and nitrite mono-oxide (NO), then NO stimulates serotonin (5HT) release at the enterochromaffin cell. Finally released 5HT stimulates 5HT3 receptor at the nerve end of the vagal afferent fiber. Functional magnetic resonance imaging (f-MRI, 4.7 T) analysis revealed that luminal sensing with 1 % (w/v) monosodium L-glutamate (MSG) in rat stomach activates both the medial preoptic area (body temperature controller) and the dorsomedial hypothalamus (basic metabolic regulator), resulting in diet-induced thermogenesis during mealing without changes of appetite for food. Interestingly, rats were forced to eat a high fat and high sugar diet with free access to 1 % (w/w) MSG and water in a choice paradigm and showed the strong preference for the MSG solution and subsequently, they displayed lower fat deposition, weight gain and blood leptin. On the other hand, these brain functional changes by the f-MRI signal after 60 mM MSG intubation into the stomach was abolished in the case of total vagotomized rats, suggesting that luminal glutamate signaling contributes to control digestion and thermogenesis without obesity. PMID:23463402

  15. Strontium and Actinide Separations from High Level Nuclear Waste Solutions using Monosodium Titanate - Actual Waste Testing

    SciTech Connect

    Peters, T.B.; Barnes, M.J.; Hobbs,D.T.; Walker, D.D.; Fondeur, F.F.; Norato, M.A.; Pulmano, R.L.; Fink, S.D.

    2005-11-01

    Pretreatment processes at the Savannah River Site will separate {sup 90}Sr, alpha-emitting and radionuclides (i.e., actinides) and {sup 137}Cs prior to disposal of the high-level nuclear waste. Separation of {sup 90}Sr and alpha-emitting radionuclides occurs by ion exchange/adsorption using an inorganic material, monosodium titanate (MST). Previously reported testing with simulants indicates that the MST exhibits high selectivity for strontium and actinides in high ionic strength and strongly alkaline salt solutions. This paper provides a summary of data acquired to measure the performance of MST to remove strontium and actinides from actual waste solutions. These tests evaluated the effects of ionic strength, mixing, elevated alpha activities, and multiple contacts of the waste with MST. Tests also provided confirmation that MST performs well at much larger laboratory scales (300-700 times larger) and exhibits little affinity for desorption of strontium and plutonium during washing.

  16. Arsenic levels in blood, urine, and hair of workers applying monosodium methanearsonate (MSMA)

    SciTech Connect

    Abdelghani, A.A.; Anderson, A.C.; Jaghabir, M.; Mather, F.

    1986-05-01

    Uptake and excretion of total arsenic from monosodium methanearsonate (MSMA) in workers who applied the herbicide was followed during the spraying season. Urine, blood, and hair samples were collected and air samples were taken from the workers' breathing zone. Arsenic concentrations in air samples ranged from 0.001-1.086 micrograms/m3. Blood and urine arsenic values ranged from 0.0-0.2 mg/L and 0.002-1.725 mg/L, respectively. The geometric mean arsenic concentration in urine increased during the week but returned to base levels on weekends. Hair arsenic concentrations ranged from 0.02-358.0 mg/kg, increased during the spraying season, and returned to pre-season levels once herbicide application ceased. Three workers had higher than normal pre-exposure hair values. However, only one of the three workers had consistently above normal values throughout the study period.

  17. Chronic effects of arsenic on American red crayfish, Procambarus clarkii, exposed to monosodium methanearsonate (MSMA) herbicide

    SciTech Connect

    Naqvi, S.M. ); Flagge, C.T. )

    1990-07-01

    Bioaccumulative and biomagnifying effects of arsenic on crayfish have been reported. However, no work has been done on the chronic effects of this heavy metal on crayfish populations. There is a great concern for MSMA (Monosodium Methanearsonate) herbicide in the vicinity of natural waters due to its high water solubility and bioaccumulative potential. American red crayfish (Procambarus clarkii) account for 98% of the annual crayfish harvest in North America. Those pesticides which have greater water solubility (i.e. MSMA) than other less soluble compounds may cause higher mortalities of aquatic organisms, or cause adverse chronic effects if the non-target animals are sublethally exposed. This work was conducted in the laboratory to assess the possible chronic effects of arsenic on crayfish.

  18. CHARACTERIZATION OF MODIFIED MONOSODIUM TITANATE - AN IMPROVED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS

    SciTech Connect

    Hobbs, D.; Taylor-Pashow, K.; Missimer, D.

    2010-12-21

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, {sup 90}Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. An inorganic sorbent, monosodium titanate (MST), is currently used to remove {sup 90}Sr and alpha-emitting radionuclides, while a caustic-side solvent extraction process is used for removing {sup 134,137}Cs. A new peroxotitanate material, modified MST, or mMST, has recently been developed and has shown increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the current baseline material, MST. This paper describes recent results focused on further characterization of this material.

  19. The glutamate homeostasis hypothesis of addiction.

    PubMed

    Kalivas, Peter W

    2009-08-01

    Addiction is associated with neuroplasticity in the corticostriatal brain circuitry that is important for guiding adaptive behaviour. The hierarchy of corticostriatal information processing that normally permits the prefrontal cortex to regulate reinforcement-seeking behaviours is impaired by chronic drug use. A failure of the prefrontal cortex to control drug-seeking behaviours can be linked to an enduring imbalance between synaptic and non-synaptic glutamate, termed glutamate homeostasis. The imbalance in glutamate homeostasis engenders changes in neuroplasticity that impair communication between the prefrontal cortex and the nucleus accumbens. Some of these pathological changes are amenable to new glutamate- and neuroplasticity-based pharmacotherapies for treating addiction. PMID:19571793

  20. Novel flavours paired with glutamate condition increased intake in older adults in the absence of changes in liking.

    PubMed

    Dermiki, Maria; Prescott, John; Sargent, Laura J; Willway, Joanne; Gosney, Margot A; Methven, Lisa

    2015-07-01

    Previous research on the repeat exposure to a novel flavour combined with monosodium glutamate (MSG) has shown an increase in liking and consumption for the particular flavour. The aim of the current work was to investigate whether this could also be observed in the case of older people, since they are most affected by undernutrition in the developed world and ways to increase consumption of food are of significant importance for this particular age group. For this study, 40 older adults (age 65-88) repeatedly consumed potato soup with two novel flavours (lemongrass and cumin) which were either with or without a high level of MSG (5% w/w). A randomized single blind within-subject design was implemented, where each participant was exposed to both soup flavours three times over 6 days, with one of the soup flavours containing MSG. After three repeat exposures, consumption increased significantly for the soups where the flavours had contained MSG during the repeated exposure (mean weight consumed increased from 123 to 164 g, p = 0.017), implying that glutamate conditioned for increased wanting and consumption, despite the fact that the liking for the soup had not increased. PMID:25754148

  1. Insulin-regulated aminopeptidase in adipocyte is Cys-specific and affected by obesity.

    PubMed

    Alponti, Rafaela Fadoni; Viana, Luciana Godoy; Yamanouye, Norma; Silveira, Paulo Flavio

    2015-08-01

    Insulin-regulated aminopeptidase (IRAP, EC 3.4.11.3) in adipocytes is well known to traffic between high (HDM) and low (LDM) density microsomal fractions toward the plasma membrane (MF) under stimulation by insulin. However, its catalytic preference for aminoacyl substrates with N-terminal Leu or Cys is controversial. Furthermore, possible changes in its traffic under metabolic challenges are unknown. The present study investigated the catalytic activity attributable to EC 3.4.11.3 in HDM, LDM and MF from isolated adipocytes of healthy (C), food deprived (FD) and monosodium glutamate (MSG) obese rats on aminoacyl substrates with N-terminal Cys or Leu, in absence or presence of insulin. Efficacy and reproducibility of subcellular adipocyte fractionation procedure were demonstrated. Comparison among HDM vs LDM vs MF intragroup revealed that hydrolytic activity trafficking from LDM to MF under influence of insulin in C, MSG and FD is only on N-terminal Cys. In MSG the same pattern of anterograde traffic and aminoacyl preference occurred independently of insulin stimulation. The pathophysiological significance of IRAP in adipocytes seems to be linked to comprehensive energy metabolism related roles of endogenous substrates with N-terminal cysteine pair such as vasopressin and oxytocin. PMID:25999180

  2. Synaptic Glutamate Spillover Due to Impaired Glutamate Uptake Mediates Heroin Relapse

    PubMed Central

    Scofield, Michael D.; Boger, Heather; Hensley, Megan; Kalivas, Peter W.

    2014-01-01

    Reducing the enduring vulnerability to relapse is a therapeutic goal in treating drug addiction. Studies with animal models of drug addiction show a marked increase in extrasynaptic glutamate in the core subcompartment of the nucleus accumbens (NAcore) during reinstated drug seeking. However, the synaptic mechanisms linking drug-induced changes in extrasynaptic glutamate to relapse are poorly understood. Here, we discovered impaired glutamate elimination in rats extinguished from heroin self-administration that leads to spillover of synaptically released glutamate into the nonsynaptic extracellular space in NAcore and investigated whether restoration of glutamate transport prevented reinstated heroin seeking. Through multiple functional assays of glutamate uptake and analyzing NMDA receptor-mediated currents, we show that heroin self-administration produced long-lasting downregulation of glutamate uptake and surface expression of the transporter GLT-1. This downregulation was associated with spillover of synaptic glutamate to extrasynaptic NMDA receptors within the NAcore. Ceftriaxone restored glutamate uptake and prevented synaptic glutamate spillover and cue-induced heroin seeking. Ceftriaxone-induced inhibition of reinstated heroin seeking was blocked by morpholino-antisense targeting GLT-1 synthesis. These data reveal that the synaptic glutamate spillover in the NAcore results from reduced glutamate transport and is a critical pathophysiological mechanism underling reinstated drug seeking in rats extinguished from heroin self-administration. PMID:24741055

  3. Regional brain glutamate transport in rats at normal and raised concentrations of circulating glutamate.

    PubMed

    Hawkins, R A; DeJoseph, M R; Hawkins, P A

    1995-08-01

    The permeability of the blood-brain barrier to glutamate was measured by quantitative autoradiography in brains of control rats (average plasma glutamate concentration of 95 microns) and rats infused with glutamate (average plasma glutamate concentration of 837 microns). Measurements of glutamate permeability were initiated by the injection of [14C]glutamate and stopped at 1 min to avoid the accumulation of [14C]glutamate metabolites. Glutamate entered the brain at a slow rate, with an average permeability-surface area product of 7 microliters.min-g-1, except in those areas known to have fenestrated capillaries. Glutamate accumulated in the choroid plexus of ventricles, but did not seem to enter the cerebrospinal fluid in detectable amounts regardless of the circulating concentration. Glutamate accumulated in circumventricular organs, such as the median eminence, where the radioactivity was localized without detectable spread. Infusion of glutamate to create high plasma concentrations did not result in greater spread of [14C]glutamate beyond the immediate vicinity of the circumventricular organs. PMID:7648616

  4. Conversion of agroindustrial residues for high poly(γ-glutamic acid) production by Bacillus subtilis NX-2 via solid-state fermentation.

    PubMed

    Tang, Bao; Xu, Hong; Xu, Zongqi; Xu, Cen; Xu, Zheng; Lei, Peng; Qiu, Yibin; Liang, Jinfeng; Feng, Xiaohai

    2015-04-01

    Poly(γ-glutamic acid) (γ-PGA) production by Bacillus subtilis NX-2 was carried out through solid-state fermentation with dry mushroom residues (DMR) and monosodium glutamate production residues (MGPR; a substitute of glutamate) for the first time. Dry shiitake mushroom residue (DSMR) was found to be the most suitable solid substrate among these DMRs; the optimal DSMR-to-MGPR ratio was optimized as 12:8. To increase γ-PGA production, industrial waste glycerol was added as a carbon source supplement to the solid-state medium. As a result, γ-PGA production increased by 34.8%. The batch fermentation obtained an outcome of 115.6 g kg(-1) γ-PGA and 39.5×10(8) colony forming units g(-1) cells. Furthermore, a satisfactory yield of 107.7 g kg(-1) γ-PGA was achieved by compost experiment on a scale of 50 kg in open air, indicating that economically large-scale γ-PGA production was feasible. Therefore, this study provided a novel method to produce γ-PGA from abundant and low-cost agroindustrial residues. PMID:25670398

  5. Glutamate: Tastant and Neuromodulator in Taste Buds.

    PubMed

    Vandenbeuch, Aurelie; Kinnamon, Sue C

    2016-07-01

    In taste buds, glutamate plays a double role as a gustatory stimulus and neuromodulator. The detection of glutamate as a tastant involves several G protein-coupled receptors, including the heterodimer taste receptor type 1, member 1 and 3 as well as metabotropic glutamate receptors (mGluR1 and mGluR4). Both receptor types participate in the detection of glutamate as shown with knockout animals and selective antagonists. At the basal part of taste buds, ionotropic glutamate receptors [N-methyl-d-aspartate (NMDA) and non-NMDA] are expressed and participate in the modulation of the taste signal before its transmission to the brain. Evidence suggests that glutamate has an efferent function on taste cells and modulates the release of other neurotransmitters such as serotonin and ATP. This short article reviews the recent developments in the field with regard to glutamate receptors involved in both functions as well as the influence of glutamate on the taste signal. PMID:27422519

  6. Glutamate Transporter-Mediated Glutamate Secretion in the Mammalian Pineal Gland

    PubMed Central

    Kim, Mean-Hwan; Uehara, Shunsuke; Muroyama, Akiko; Hille, Bertil; Moriyama, Yoshinori; Koh, Duk-Su

    2008-01-01

    Glutamate transporters are expressed throughout the central nervous system where their major role is to clear released glutamate from presynaptic terminals. Here we report a novel function of the transporter in rat pinealocytes. This electrogenic transporter conducted inward current in response to L-glutamate and L- or D-aspartate and depolarized the membrane in patch clamp experiments. Ca2+ imaging demonstrated that the transporter-mediated depolarization induced a significant Ca2+ influx through voltage-gated Ca2+ channels. The Ca2+ rise finally evoked glutamate exocytosis as detected by carbon-fiber amperometry and by high-performance liquid chromatography. In pineal slices with densely packed pinealocytes, glutamate released from the cells effectively activated glutamate transporters in neighboring cells. The Ca2+ signal generated by KCl depolarization or acetylcholine propagated through several cell layers by virtue of the regenerative ‘glutamate-induced glutamate release’. Therefore we suggest that glutamate transporters mediate synchronized elevation of L-glutamate and thereby efficiently down-regulate melatonin secretion via previously identified inhibitory metabotropic glutamate receptors in the pineal gland. PMID:18945893

  7. Glutamate Racemase Mutants of Bacillus anthracis

    PubMed Central

    Oh, So-Young; Richter, Stefan G.; Missiakas, Dominique M.

    2015-01-01

    ABSTRACT d-Glutamate is an essential component of bacterial peptidoglycan and a building block of the poly-γ-d-glutamic acid (PDGA) capsule of Bacillus anthracis, the causative agent of anthrax. Earlier work suggested that two glutamate racemases, encoded by racE1 and racE2, are each essential for growth of B. anthracis, supplying d-glutamic acid for the synthesis of peptidoglycan and PDGA capsule. Earlier work could not explain, however, why two enzymes that catalyze the same reaction may be needed for bacterial growth. Here, we report that deletion of racE1 or racE2 did not prevent growth of B. anthracis Sterne (pXO1+ pXO2−), the noncapsulating vaccine strain, or of B. anthracis Ames (pXO1+ pXO2+), a fully virulent, capsulating isolate. While mutants with deletions in racE1 and racE2 were not viable, racE2 deletion delayed vegetative growth of B. anthracis following spore germination and caused aberrant cell shapes, phenotypes that were partially restored by exogenous d-glutamate. Deletion of racE1 or racE2 from B. anthracis Ames did not affect the production or stereochemical composition of the PDGA capsule. A model is presented whereby B. anthracis, similar to Bacillus subtilis, utilizes two functionally redundant racemase enzymes to synthesize d-glutamic acid for peptidoglycan synthesis. IMPORTANCE Glutamate racemases, enzymes that convert l-glutamate to d-glutamate, are targeted for antibiotic development. Glutamate racemase inhibitors may be useful for the treatment of bacterial infections such as anthrax, where the causative agent, B. anthracis, requires d-glutamate for the synthesis of peptidoglycan and poly-γ-d-glutamic acid (PDGA) capsule. Here we show that B. anthracis possesses two glutamate racemase genes that can be deleted without abolishing either bacterial growth or PDGA synthesis. These data indicate that drug candidates must inhibit both glutamate racemases, RacE1 and RacE2, in order to block B. anthracis growth and achieve therapeutic

  8. Glutamate-gated Chloride Channels*

    PubMed Central

    Wolstenholme, Adrian J.

    2012-01-01

    Glutamate-gated chloride channels (GluCls) are found only in protostome invertebrate phyla but are closely related to mammalian glycine receptors. They have a number of roles in these animals, controlling locomotion and feeding and mediating sensory inputs into behavior. In nematodes and arthropods, they are targeted by the macrocyclic lactone family of anthelmintics and pesticides, making the GluCls of considerable medical and economic importance. Recently, the three-dimensional structure of a GluCl was solved, the first for any eukaryotic ligand-gated anion channel, revealing a macrocyclic lactone-binding site between the channel domains of adjacent subunits. This minireview will highlight some unique features of the GluCls and illustrate their contribution to our knowledge of the entire Cys loop ligand-gated ion channel superfamily. PMID:23038250

  9. Different pools of glutamate receptors mediate sensitivity to ambient glutamate in the cochlear nucleus

    PubMed Central

    Yang, Yang

    2015-01-01

    Ambient glutamate plays an important role in pathological conditions, such as stroke, but its role during normal activity is not clear. In addition, it is not clear how ambient glutamate acts on glutamate receptors with varying affinities or subcellular localizations. To address this, we studied “endbulb of Held” synapses, which are formed by auditory nerve fibers onto bushy cells (BCs) in the anteroventral cochlear nucleus. When ambient glutamate was increased by applying the glutamate reuptake inhibitor TFB-TBOA, BCs depolarized as a result of activation of N-methyl-d-aspartate receptors (NMDARs) and group I metabotropic glutamate receptors (mGluRs). Application of antagonists against NMDARs (in 0 Mg2+) or mGluRs caused hyperpolarization, indicating that these receptors were bound by a tonic source of glutamate. AMPA receptors did not show these effects, consistent with their lower glutamate affinity. We also evaluated the subcellular localization of the receptors activated by ambient glutamate. The mGluRs were not activated by synaptic stimulation and thus appear to be exclusively extrasynaptic. By contrast, NMDARs in both synaptic and extrasynaptic compartments were activated by ambient glutamate, as shown using the use-dependent antagonist MK-801. Levels of ambient glutamate appeared to be regulated in a spike-independent manner, and glia likely play a major role. These low levels of ambient glutamate likely have functional consequences, as even low concentrations of TBOA caused significant increases in BC spiking following synaptic stimulation. These results indicate that normal resting potential appears to be poised in the region of maximal sensitivity to small changes in ambient glutamate. PMID:25855696

  10. Different pools of glutamate receptors mediate sensitivity to ambient glutamate in the cochlear nucleus.

    PubMed

    Yang, Yang; Xu-Friedman, Matthew A

    2015-06-01

    Ambient glutamate plays an important role in pathological conditions, such as stroke, but its role during normal activity is not clear. In addition, it is not clear how ambient glutamate acts on glutamate receptors with varying affinities or subcellular localizations. To address this, we studied "endbulb of Held" synapses, which are formed by auditory nerve fibers onto bushy cells (BCs) in the anteroventral cochlear nucleus. When ambient glutamate was increased by applying the glutamate reuptake inhibitor TFB-TBOA, BCs depolarized as a result of activation of N-methyl-D-aspartate receptors (NMDARs) and group I metabotropic glutamate receptors (mGluRs). Application of antagonists against NMDARs (in 0 Mg(2+)) or mGluRs caused hyperpolarization, indicating that these receptors were bound by a tonic source of glutamate. AMPA receptors did not show these effects, consistent with their lower glutamate affinity. We also evaluated the subcellular localization of the receptors activated by ambient glutamate. The mGluRs were not activated by synaptic stimulation and thus appear to be exclusively extrasynaptic. By contrast, NMDARs in both synaptic and extrasynaptic compartments were activated by ambient glutamate, as shown using the use-dependent antagonist MK-801. Levels of ambient glutamate appeared to be regulated in a spike-independent manner, and glia likely play a major role. These low levels of ambient glutamate likely have functional consequences, as even low concentrations of TBOA caused significant increases in BC spiking following synaptic stimulation. These results indicate that normal resting potential appears to be poised in the region of maximal sensitivity to small changes in ambient glutamate. PMID:25855696

  11. REVIEW OF EXPERIMENTAL STUDIES INVESTIGATING THE RATE OF STRONTIUM AND ACTINIDE ADSORPTION BY MONOSODIUM TITANATE

    SciTech Connect

    Hobbs, D.

    2010-10-01

    A number of laboratory studies have been conducted to determine the influence of mixing and mixing intensity, solution ionic strength, initial sorbate concentrations, temperature, and monosodium titanate (MST) concentration on the rates of sorbate removal by MST in high-level nuclear waste solutions. Of these parameters, initial sorbate concentrations, ionic strength, and MST concentration have the greater impact on sorbate removal rates. The lack of a significant influence of mixing and mixing intensity on sorbate removal rates indicates that bulk solution transport is not the rate controlling step in the removal of strontium and actinides over the range of conditions and laboratory-scales investigated. However, bulk solution transport may be a significant parameter upon use of MST in a 1.3 million-gallon waste tank such as that planned for the Small Column Ion Exchange (SCIX) program. Thus, Savannah River National Laboratory (SRNL) recommends completing the experiments in progress to determine if mixing intensity influences sorption rates under conditions appropriate for this program. Adsorption models have been developed from these experimental studies that allow prediction of strontium (Sr), plutonium (Pu), neptunium (Np) and uranium (U) concentrations as a function of contact time with MST. Fairly good agreement has been observed between the predicted and measured sorbate concentrations in the laboratory-scale experiments.

  12. The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats

    PubMed Central

    Kim, Youngkyung; Kim, Eun-hye; Lee, Kyu Sang; Lee, Koeun; Park, Sung Ho; Na, Sook Hyun; Ko, Cheolwoong; Yooon, Young Wook

    2016-01-01

    This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, 8 mg/50 µl) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord. PMID:26807032

  13. The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats.

    PubMed

    Kim, Youngkyung; Kim, Eun-Hye; Lee, Kyu Sang; Lee, Koeun; Park, Sung Ho; Na, Sook Hyun; Ko, Cheolwoong; Kim, Junesun; Yooon, Young Wook

    2016-01-01

    This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, 8 mg/50 µl) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord. PMID:26807032

  14. Effect of monosodium methanarsonate application on cuticle wax content of cocklebur and cotton plants.

    PubMed

    Keese, Renee J; Camper, N Dwight

    2006-01-01

    Leaf cuticle waxes were extracted from monosodium methanearsonate (MSMA)-resistant (R) and -susceptible (S) common cocklebur (Xanthium strumarium L.) and cotton (Gossypium hirsutum L.) plants at 0, 3, 5, and 7 days after treatment (DAT) following 1x and 2x MSMA applications. Wax constituents were analyzed by gas chromatography (GC) with flame ionization detection and compared to alkane and alcohol standards of carbon lengths varying from C21 to C30. Differences in waxes were calculated and reported as change per ng mm2-1. Tricosane (C23) was found to increase following MSMA applications. All other alkanes decreased by 7 DAT, with some showing a linear effect over time in the R-cocklebur. Alcohol constituents were also observed to decrease by 7 DAT. Total arsenic in the extracted wax fraction was determined, with greatest quantities detected in the R-cocklebur. Wax changes are not believed to play a role in cotton tolerance, since changes in cuticle concentrations were minimal. Cocklebur resistance to MSMA is not due to cuticle constituents; the wax changes are a secondary effect in response to herbicide application. PMID:16893783

  15. Vesicular Glutamate Transport Promotes Dopamine Storage and Glutamate Corelease In Vivo

    PubMed Central

    Hnasko, Thomas S.; Chuhma, Nao; Zhang, Hui; Goh, Germaine Y.; Sulzer, David; Palmiter, Richard D.; Rayport, Stephen; Edwards, Robert H.

    2010-01-01

    SUMMARY Dopamine neurons in the ventral tegmental area (VTA) play an important role in the motivational systems underlying drug addiction, and recent work has suggested that they also release the excitatory neurotransmitter glutamate. To assess a physiological role for glutamate corelease, we disrupted the expression of vesicular glutamate transporter 2 selectively in dopamine neurons. The conditional knockout abolishes glutamate release from midbrain dopamine neurons in culture and severely reduces their excitatory synaptic output in mesoaccumbens slices. Baseline motor behavior is not affected, but stimulation of locomotor activity by cocaine is impaired, apparently through a selective reduction of dopamine stores in the projection of VTA neurons to ventral striatum. Glutamate co-entry promotes monoamine storage by increasing the pH gradient that drives vesicular monoamine transport. Remarkably, low concentrations of glutamate acidify synaptic vesicles more slowly but to a greater extent than equimolar Cl−, indicating a distinct, presynaptic mechanism to regulate quantal size. PMID:20223200

  16. Glutamate Receptor Stimulation Up-Regulates Glutamate Uptake in Human Müller Glia Cells.

    PubMed

    López-Colomé, Ana María; López, Edith; Mendez-Flores, Orquidia G; Ortega, Arturo

    2016-07-01

    Glutamate, the main excitatory amino acid in the vertebrate retina, is a well know activator of numerous signal transduction pathways, and has been critically involved in long-term synaptic changes acting through ionotropic and metabotropic glutamate receptors. However, recent findings underlining the importance of intensity and duration of glutamate stimuli for specific neuronal responses, including excitotoxicity, suggest a crucial role for Na(+)-dependent glutamate transporters, responsible for the removal of this neurotransmitter from the synaptic cleft, in the regulation of glutamate-induced signaling. Transporter proteins are expressed in neurons and glia cells, albeit most of glutamate uptake occurs in the glial compartment. Within the retina, Müller glia cells are in close proximity to glutamatergic synapses and participate in the recycling of glutamate through the glutamate/glutamine shuttle. In this context, we decided to investigate a plausible role of glutamate as a regulatory signal for its own transport in human retinal glia cells. To this end, we determined [(3)H]-D-aspartate uptake in cultures of spontaneously immortalized human Müller cells (MIO-M1) exposed to distinct glutamatergic ligands. A time and dose-dependent increase in the transporter activity was detected. This effect was dependent on the activation of the N-methyl D-aspartate subtype of glutamate receptors, due to a dual effect: an increase in affinity and an augmented expression of the transporter at the plasma membrane, as established via biotinylation experiments. Furthermore, a NMDA-dependent association of glutamate transporters with the cystoskeletal proteins ezrin and glial fibrillary acidic protein was also found. These results add a novel mediator of the glutamate transporter modulation and further strengthen the notion of the critical involvement of glia cells in synaptic function. PMID:27017513

  17. Glutamate Receptor Dynamics in Dendritic Microdomains

    PubMed Central

    Newpher, Thomas M.; Ehlers, Michael D.

    2008-01-01

    Among diverse factors regulating excitatory synaptic transmission, the abundance of postsynaptic glutamate receptors figures prominently in molecular memory and learning-related synaptic plasticity. To allow for both long-term maintenance of synaptic transmission and acute changes in synaptic strength, the relative rates of glutamate receptor insertion and removal must be tightly regulated. Interactions with scaffolding proteins control the targeting and signaling properties of glutamate receptors within the postsynaptic membrane. In addition, extrasynaptic receptor populations control the equilibrium of receptor exchange at synapses and activate distinct signaling pathways involved in plasticity. Here, we review recent findings that have shaped our current understanding of receptor mobility between synaptic and extrasynaptic compartments at glutamatergic synapses, focusing on AMPA and NMDA receptors. We also examine the cooperative relationship between intracellular trafficking and surface diffusion of glutamate receptors that underlies the expression of learning-related synaptic plasticity. PMID:18498731

  18. Mechanism for the activation of glutamate receptors

    Cancer.gov

    Scientists at the NIH have used a technique called cryo-electron microscopy to determine a molecular mechanism for the activation and desensitization of ionotropic glutamate receptors, a prominent class of neurotransmitter receptors in the brain and spina

  19. [Glutamate transporter dysfunction and major mental illnesses].

    PubMed

    Tanaka, Kohichi

    2016-01-01

    Glutamate is the main excitatory neurotransmitter in the central nervous system and plays an important role in most aspects of normal brain function. In spite of its importance as a neurotransmitter, excess glutamate is toxic to neurons. Clearance of extracellular glutamate is critical for maintenance of low extracellular glutamate concentration, and occurs in large part through the activity of GLT1 (EAAT2) and GLAST (EAAT1), which are primarily expressed by astrocytes. Rare variants and down-regulation of GLT1 and GLAST, in psychiatric disorders have been reported. In this review, we demonstrate that various kinds of GLT1 and/or GLAST knockout mice replicate many aspects of the behavioral abnormalities seen in major mental illnesses including schizophrenia, depression, obsessive -compulsive disorders, autism, epilepsy and addiction. PMID:26793898

  20. DNA nanopore translocation in glutamate solutions

    NASA Astrophysics Data System (ADS)

    Plesa, C.; van Loo, N.; Dekker, C.

    2015-08-01

    Nanopore experiments have traditionally been carried out with chloride-based solutions. Here we introduce silver/silver-glutamate-based electrochemistry as an alternative, and study the viscosity, conductivity, and nanopore translocation characteristics of potassium-, sodium-, and lithium-glutamate solutions. We show that it has a linear response at typical voltages and can be used to detect DNA translocations through a nanopore. The glutamate anion also acts as a redox-capable thickening agent, with high-viscosity solutions capable of slowing down the DNA translocation process by up to 11 times, with a corresponding 7 time reduction in signal. These results demonstrate that glutamate can replace chloride as the primary anion in nanopore resistive pulse sensing.

  1. [Glutamate neurotransmission, stress and hormone secretion].

    PubMed

    Jezová, D; Juránková, E; Vigas, M

    1995-11-01

    Glutamate neurotransmission has been investigated in relation to several physiological processes (learning, memory) as well as to neurodegenerative and other disorders. Little attention has been paid to its involvement in neuroendocrine response during stress. Penetration of excitatory amino acids from blood to the brain is limited by the blood-brain barrier. As a consequence, several toxic effects but also bioavailability for therapeutic purposes are reduced. A free access to circulating glutamate is possible only in brain structures lacking the blood-brain barrier or under conditions of its increased permeability. Excitatory amino acids were shown to stimulate the pituitary hormone release, though the mechanism of their action is still not fully understood. Stress exposure in experimental animals induced specific changes in mRNA levels coding the glutamate receptor subunits in the hippocampus and hypothalamus. The results obtained with the use of glutamate receptor antagonists indicate that a number of specific receptor subtypes contribute to the stimulation of ACTH release during stress. The authors provided also data on the role of NMDA receptors in the control of catecholamine release, particularly in stress-induced secretion of epinephrine. These results were the first piece of evidence on the involvement of endogenous excitatory amino acids in neuroendocrine activation during stress. Neurotoxic effects of glutamate in animals are well described, especially after its administration in the neonatal period. In men, glutamate toxicity and its use as a food additive are a continuous subject of discussions. The authors found an increase in plasma cortisol and norepinephrine, but not epinephrine and prolactin, in response to the administration of a high dose of glutamate. It cannot be excluded that these effects might be induced even by lower doses in situations with increased vulnerability to glutamate action (age, individual variability). (Tab. 1, Fig. 6, Ref. 44

  2. Glutamic Acid Decarboxylation in Chlorella12

    PubMed Central

    Lane, T. R.; Stiller, Mary

    1970-01-01

    The decarboxylation of endogenous free glutamic acid by Chlorella pyrenoidosa, Marburg strain, was induced by a variety of metabolic poisons, by anaerobic conditions, and by freezing and thawing the cells. The rate of decarboxylation was proportional to the concentration of inhibitor present. Possible mechanisms which relate the effects of the various conditions on glutamate decarboxylation and oxygen consumption by Chlorella are discussed. Images PMID:5429350

  3. Ionotropic Glutamate Receptors & CNS Disorders

    PubMed Central

    Bowie, Derek

    2008-01-01

    Disorders of the central nervous system (CNS) are complex disease states that represent a major challenge for modern medicine. Although etiology is often unknown, it is established that multiple factors such as defects in genetics and/or epigenetics, the environment as well as imbalance in neurotransmitter receptor systems are all at play in determining an individual’s susceptibility to disease. Gene therapy is currently not available and therefore, most conditions are treated with pharmacological agents that modify neurotransmitter receptor signaling. Here, I provide a review of ionotropic glutamate receptors (iGluRs) and the roles they fulfill in numerous CNS disorders. Specifically, I argue that our understanding of iGluRs has reached a critical turning point to permit, for the first time, a comprehensive re-evaluation of their role in the cause of disease. I illustrate this by highlighting how defects in AMPA receptor trafficking are important to Fragile X mental retardation and ectopic expression of kainate (KA) receptor synapses contributes to the pathology of temporal lobe epilepsy. Finally, I discuss how parallel advances in studies of other neurotransmitter systems may allow pharmacologists to work towards a cure for many CNS disorders rather than developing drugs to treat their symptoms. PMID:18537642

  4. Therapeutic Potential of Metabotropic Glutamate Receptor Modulators

    PubMed Central

    Hovelsø, N; Sotty, F; Montezinho, L.P; Pinheiro, P.S; Herrik, K.F; Mørk, A

    2012-01-01

    Glutamate is the main excitatory neurotransmitter in the central nervous system (CNS) and is a major player in complex brain functions. Glutamatergic transmission is primarily mediated by ionotropic glutamate receptors, which include NMDA, AMPA and kainate receptors. However, glutamate exerts modulatory actions through a family of metabotropic G-protein-coupled glutamate receptors (mGluRs). Dysfunctions of glutamatergic neurotransmission have been implicated in the etiology of several diseases. Therefore, pharmacological modulation of ionotropic glutamate receptors has been widely investigated as a potential therapeutic strategy for the treatment of several disorders associated with glutamatergic dysfunction. However, blockade of ionotropic glutamate receptors might be accompanied by severe side effects due to their vital role in many important physiological functions. A different strategy aimed at pharmacologically interfering with mGluR function has recently gained interest. Many subtype selective agonists and antagonists have been identified and widely used in preclinical studies as an attempt to elucidate the role of specific mGluRs subtypes in glutamatergic transmission. These studies have allowed linkage between specific subtypes and various physiological functions and more importantly to pathological states. This article reviews the currently available knowledge regarding the therapeutic potential of targeting mGluRs in the treatment of several CNS disorders, including schizophrenia, addiction, major depressive disorder and anxiety, Fragile X Syndrome, Parkinson’s disease, Alzheimer’s disease and pain. PMID:22942876

  5. RADIUM AND THORIUM SORPTION BY MONOSODIUM TITANATE (MST) AND MODIFIED MST (mMST)

    SciTech Connect

    Taylor-Pashow, K.; Hobbs, D.

    2012-02-15

    A series of tests were planned to examine the removal of Ra and Th by monosodium titanate (MST) and modified monosodium titanate (mMST). Simulated waste solutions were prepared containing Ra and Th, along with Sr, Np, Pu, and U. Following simulant preparation the simulants were filtered through 0.45-m filters. Analysis of the simulants indicated no Th in the filtered solution. This is due to the very low solubility of Th in alkaline solutions. Based on the reported detection limits for {sup 228}Th by gamma analyses, the solubility of Th in the simulant solutions is < 3.0E-10 g/L or < 1.3E-12 M. Therefore, data could not be obtained regarding the removal of Th by MST and mMST; however, testing proceeded to examine the removal of Ra. Sorption testing indicated that Ra, like Sr, is very rapidly removed from solution by both MST and mMST. The Ra concentration in solution fell below the method detection limit (MDL) within 30 minutes of contact with MST, and within 2 hours of contact with mMST, when tested at 25 C using a 5.6 M Na simulant. Additional testing examined the effects of ionic strength and temperature on the MST and mMST performance. Results from these tests showed that the majority of samples still reached a Ra concentration below the MDL, indicating excellent removal. For the highest ionic strength solution (6.6 M Na), there did appear to be a slight decrease in the Ra removal by mMST, as indicated by a larger number of samples just above the MDL. The effect of temperature on {sup 226}Ra removal is indeterminate for either MST or mMST in the temperature range (25-60 C) and concentrations studied since the final soluble concentration of Ra remained at or below the detection limits for all tests. Desorption testing was also performed using decontaminated salt solution (DSS) diluted to sodium concentrations of 2 M and 0.5 M, to represent the intermediate and final stages of washing. Results from these tests indicated no desorption of any sorbents, with the

  6. Arsenic Retention in Foliage and Soil after Monosodium Methyl Arsenate (MSMA) Application to Turfgrass.

    PubMed

    Matteson, Audrey R; Gannon, Travis W; Jeffries, Matthew D; Haines, Stephanie; Lewis, Dustin F; Polizzotto, Matthew L

    2014-01-01

    Monosodium methyl arsenate (MSMA) is a commonly used herbicide for weed control in turfgrass systems. There is concern that arsenic from applied MSMA could leach to groundwater or run off into surface water, thereby threatening human and ecosystem health. The USEPA has proposed a phase-out of the herbicide but is seeking additional research about the toxicity and environmental impacts of MSMA before establishing a final ruling. Little research has systematically investigated MSMA in field-based settings; instead, risks have been inferred from isolated field measurements or model-system studies. Accordingly, the overall goal of this study was to quantify the fate of arsenic after MSMA application to a managed turfgrass system. After MSMA application to turfgrass-covered and bareground lysimeters, the majority of arsenic was retained in turfgrass foliage and soils throughout year-long experiments, with 50 to 101% of the applied arsenic recovered in turfgrass systems and 55 to 66% recovered in bareground systems. Dissolved arsenic concentrations from 76.2-cm-depth pore water in the MSMA-treated soils were consistently <2 μg L, indistinguishable from background concentrations. As measured by adsorption isotherm experiments, MSMA retention by the sandy soil from our field site was markedly less than retention by a washed sand and a clay loam. Collectively, these results suggest that under aerobic conditions, minimal arsenic leaching to groundwater would occur after a typical application of MSMA to turfgrass. However, repeated MSMA application may pose environmental risks. Additional work is needed to examine arsenic cycling near the soil surface and to define arsenic speciation changes under different soil conditions. PMID:25602572

  7. Management considerations to minimize environmental impacts of arsenic following monosodium methylarsenate (MSMA) applications to turfgrass.

    PubMed

    Mahoney, Denis J; Gannon, Travis W; Jeffries, Matthew D; Matteson, Audrey R; Polizzotto, Matthew L

    2015-03-01

    Monosodium methylarsenate (MSMA) is an organic arsenical herbicide currently utilized in turfgrass and cotton systems. In recent years, concerns over adverse impacts of arsenic (As) from MSMA applications have emerged; however, little research has been conducted in controlled field experiments using typical management practices. To address this knowledge gap, a field lysimeter experiment was conducted during 2012-2013 to determine the fate of As following MSMA applications to a bareground and an established turfgrass system. Arsenic concentrations in soil, porewater, and aboveground vegetation, were measured through one yr after treatment. Aboveground vegetation As concentration was increased compared to nontreated through 120 d after initial treatment (DAIT). In both systems, increased soil As concentrations were observed at 0-4 cm at 30 and 120 DAIT and 0-8 cm at 60 and 365 DAIT, suggesting that As was bound in shallow soil depths. Porewater As concentrations in MSMA-treated lysimeters from a 30-cm depth (22.0-83.8 μg L(-1)) were greater than those at 76-cm depth (0.4-5.1 μg L(-1)). These results were combined with previous research to devise management considerations in systems where MSMA is utilized. MSMA should not be applied if rainfall is forecasted within 7 DAIT and/or in areas with shallow water tables. Further, disposing of MSMA-treated turfgrass aboveground vegetation in a confined area - a common management practice for turfgrass clippings - may be of concern due to As release to surface water or groundwater as the vegetation decomposes. Finally, long-term MSMA use may cause soil As accumulation and thus downward migration of As over time; therefore, MSMA should be used in rotation with other herbicides. PMID:25556868

  8. The Degradation of 14C-Glutamic Acid by L-Glutamic Acid Decarboxylase.

    ERIC Educational Resources Information Center

    Dougherty, Charles M; Dayan, Jean

    1982-01-01

    Describes procedures and semi-micro reaction apparatus (carbon dioxide trap) to demonstrate how a particular enzyme (L-Glutamic acid decarboxylase) may be used to determine the site or sites of labeling in its substrate (carbon-14 labeled glutamic acid). Includes calculations, solutions, and reagents used. (Author/SK)

  9. Glutamate receptor ligands as anxiolytics.

    PubMed

    Chojnacka-Wójcik, E; Kłodzinska, A; Pilc, A

    2001-08-01

    The glutamatergic system has received considerable attention over recent years as a potential target for anxiolytic drugs. In spite of the pronounced anxiolytic-like effects of competitive and non-competitive antagonists of NMDA receptors in animal models of anxiety, these substances can not be regarded as potential anxiolytic drugs, mainly due to their side-effect profiles (eg, ataxia, myorelaxation, impairment of learning and memory processes and psychotomimetic effects). Antagonists and partial agonists of the glycine, receptor inhibit function of the NMDA receptor complex and evoke in animals an anxiolytic-like response. Although data concerning anti-anxiety-like effects of glycine, receptor antagonists are not very promising, studies are underway to develop new, brain-penetrating agents devoid of side effects. Further developments are necessary to more fully elucidate the possible involvement of AMPA/kainate receptors in anxiety. The recent discovery of metabotropic glutamate receptors, which modulate the function of the glutamatergic system, offers new hope for discovery of a new generation of anxiolytics. MPEP, a highly selective, brain penetrable, noncompetitive mGlu5 receptor antagonist, evokes anxiolytic-like effects in several animal models of anxiety, remaining remarkably free of side effects. LY-354740, a selective brain-penetrable group II mGlu receptor agonist, evokes marked anxiolytic-like effects in animal models of anxiety. LY-354740 causes mild sedation in mice, does not disturb motor coordination and has no potential to cause dependence. Therefore mGlu receptor ligands may become the anxiolytics of the future, free from the side effects characteristic of benzodiazepines. PMID:11892923

  10. Glutamate Metabolism in Major Depressive Disorder

    PubMed Central

    Abdallah, Chadi G.; Jiang, Lihong; De Feyter, Henk M.; Fasula, Madonna; Krystal, John H.; Rothman, Douglas L.; Mason, Graeme F.; Sanacora, Gerard

    2015-01-01

    Objective Emerging evidence suggests abnormalities in amino acid neurotransmitter function and impaired energy metabolism contribute to the underlying pathophysiology of Major Depressive Disorder (MDD). To test whether impairments in energetics and glutamate neurotransmitter cycling are present in MDD we used in vivo 13C magnetic resonance spectroscopy (13C MRS) to measure these fluxes in individuals diagnosed with MDD relative to non-depressed subjects. Method 1H MRS and 13C MRS data were collected on 23 medication-free MDD and 17 healthy subjects. 1H MRS provided total glutamate and GABA concentrations, and 13C MRS, coupled with intravenous infusion of [1-13C]-glucose, provided measures of the neuronal tricarboxylic acid cycle (VTCAN) for mitochondrial energy production, GABA synthesis, and glutamate/glutamine cycling, from voxels placed in the occipital cortex. Results Our main finding was that mitochondrial energy production of glutamatergic neurons was reduced by 26% in MDD subjects (t = 2.57, p = 0.01). Paradoxically we found no difference in the rate of glutamate/glutamine cycle (Vcycle). We also found a significant correlation between glutamate concentrations and Vcycle considering the total sample. Conclusions We interpret the reduction in mitochondrial energy production as being due to either mitochondrial dysfunction or a reduction in proper neuronal input or synaptic strength. Future MRS studies could help distinguish these possibilities. PMID:25073688

  11. Single channel kinetics of a glutamate receptor.

    PubMed Central

    Kerry, C J; Kits, K S; Ramsey, R L; Sansom, M S; Usherwood, P N

    1987-01-01

    The glutamate receptor-channel of locust muscle membrane was studied using the patch-clamp technique. Muscles were pretreated with concanavalin A to block receptor-channel desensitization, thus facilitating analysis of receptor-channel gating kinetics. Single channel kinetics were analyzed to aid in identification of the molecular basis of channel gating. Channel dwell-time distributions and dwell-time autocorrelation functions were calculated from single channel data recorded in the precence of 10-4M glutamate. Analysis of the dwell time distributions in terms of mixtures of exponential functions revealed there to be at least three open states of the receptor-channel and at least four closed states. Autocorrelation function analysis showed there to be at least three pathways linking the open states with the closed. This results in a minimal scheme for gating of the glutamate receptor-channel, which is suggestive of allosteric models of receptor-channel gating. PMID:2436676

  12. Single Channel Kinetics of a Glutamate Receptor

    PubMed Central

    Kerry, Cathryn J.; Kits, Karel S.; Ramsey, Robert L.; Sansom, Mark S. P.; Usherwood, Peter N. R.

    1986-01-01

    The glutamate receptor-channel of locust muscle membrane was studied using the patch-clamp technique. Muscles were pretreated with concanavalin A to block receptor-channel desensitization, thus facilitating analysis of receptor-channel gating kinetics. Single channel kinetics were analyzed to aid in identification of the molecular basis of channel gating. Channel dwell-time distributions and dwell-time autocorrelation functions were calculated from single channel data recorded in the presence of 10-4 M glutamate. Analysis of the dwell time distributions in terms of mixtures of exponential functions revealed there to be at least three open states of the receptor-channel and at least four closed states. Autocorrelation function analysis showed there to be at least three pathways linking the open states with the closed. This results in a minimal scheme for gating of the glutamate receptor-channel, which is suggestive of allosteric models of receptor-channel gating. PMID:19431683

  13. Exposure to enriched environment decreases neurobehavioral deficits induced by neonatal glutamate toxicity.

    PubMed

    Horvath, Gabor; Reglodi, Dora; Vadasz, Gyongyver; Farkas, Jozsef; Kiss, Peter

    2013-01-01

    Environmental enrichment is a popular strategy to enhance motor and cognitive performance and to counteract the effects of various harmful stimuli. The protective effects of enriched environment have been shown in traumatic, ischemic and toxic nervous system lesions. Monosodium glutamate (MSG) is a commonly used taste enhancer causing excitotoxic effects when given in newborn animals. We have previously demonstrated that MSG leads to a delay in neurobehavioral development, as shown by the delayed appearance of neurological reflexes and maturation of motor coordination. In the present study we aimed at investigating whether environmental enrichment is able to decrease the neurobehavioral delay caused by neonatal MSG treatment. Newborn pups were treated with MSG subcutaneously on postnatal days 1, 5 and 9. For environmental enrichment, we placed rats in larger cages, supplemented with different toys that were altered daily. Normal control and enriched control rats received saline treatment only. Physical parameters such as weight, day of eye opening, incisor eruption and ear unfolding were recorded. Animals were observed for appearance of reflexes such as negative geotaxis, righting reflexes, fore- and hindlimb grasp, fore- and hindlimb placing, sensory reflexes and gait. In cases of negative geotaxis, surface righting and gait, the time to perform the reflex was also recorded daily. For examining motor coordination, we performed grid walking, footfault, rope suspension, rota-rod, inclined board and walk initiation tests. We found that enriched environment alone did not lead to marked alterations in the course of development. On the other hand, MSG treatment caused a slight delay in reflex development and a pronounced delay in weight gain and motor coordination maturation. This delay in most signs and tests could be reversed by enriched environment: MSG-treated pups kept under enriched conditions showed no weight retardation, no reflex delay in some signs and

  14. Permanent Uncoupling of Male-specific CYP2C11 Transcription / Translation by Perinatal Glutamate

    PubMed Central

    Banerjee, Sarmistha; Das, Rajat Kumar; Giffear, Kelly A.; Shapiro, Bernard H.

    2015-01-01

    Perinatal exposure of rats and mice to the typically reported 4mg/g bd wt dose of monosodium glutamate (MSG) results in a complete block in GH secretion as well as obesity, growth retardation and a profound suppression of several cytochrome P450s, including CYP2C11, the predominant male-specific isoform - all irreversible effects. In contrast, we have found that a lower dose of the food additive, 2mg/g bd wt on alternate days for the first 9 days of life results in a transient neonatal depletion of plasma GH, a subsequent permanent overexpression of CYP2C11 as well as subnormal (mini) GH pulse amplitudes in an otherwise normal adult masculine episodic GH profile. The overexpressed CYP2C11 was characterized by a 250% increase in mRNA, but only a 40 to 50% increase in CYP2C11 protein and its catalytic activity. Using freshly isolated hepatocytes as well as primary cultures exposed to the masculine-like episodic GH profile, we observed normal induction, activation, nuclear translocation and binding to the CYP2C11 promoter of the GH-dependent signal transducers required for CYP2C11 transcription. The disproportionately lower expression levels of CYP2C11 protein were associated with dramatically high expression levels of an aberrant, presumably nontranslated CYP2C11 mRNA, a 200% increase in CYP2C11 ubiquitination and a 70–80% decline in miRNAs associated, at normal levels, with a suppression of CYP2C expression. Whereas the GH-responsiveness of CYP2C7 and CYP2C6 as well as albumin was normal in the MSG-derived hepatocytes, the abnormal expression of CYP2C11 was permanent and irreversible. PMID:25697375

  15. Permanent uncoupling of male-specific CYP2C11 transcription/translation by perinatal glutamate.

    PubMed

    Banerjee, Sarmistha; Das, Rajat Kumar; Giffear, Kelly A; Shapiro, Bernard H

    2015-04-01

    Perinatal exposure of rats and mice to the typically reported 4mg/g bd wt dose of monosodium glutamate (MSG) results in a complete block in GH secretion as well as obesity, growth retardation and a profound suppression of several cytochrome P450s, including CYP2C11, the predominant male-specific isoform--all irreversible effects. In contrast, we have found that a lower dose of the food additive, 2mg/g bd wt on alternate days for the first 9days of life results in a transient neonatal depletion of plasma GH, a subsequent permanent overexpression of CYP2C11 as well as subnormal (mini) GH pulse amplitudes in an otherwise normal adult masculine episodic GH profile. The overexpressed CYP2C11 was characterized by a 250% increase in mRNA, but only a 40 to 50% increase in CYP2C11 protein and its catalytic activity. Using freshly isolated hepatocytes as well as primary cultures exposed to the masculine-like episodic GH profile, we observed normal induction, activation, nuclear translocation and binding to the CYP2C11 promoter of the GH-dependent signal transducers required for CYP2C11 transcription. The disproportionately lower expression levels of CYP2C11 protein were associated with dramatically high expression levels of an aberrant, presumably nontranslated CYP2C11 mRNA, a 200% increase in CYP2C11 ubiquitination and a 70-80% decline in miRNAs associated, at normal levels, with a suppression of CYP2C expression. Whereas the GH-responsiveness of CYP2C7 and CYP2C6 as well as albumin was normal in the MSG-derived hepatocytes, the abnormal expression of CYP2C11 was permanent and irreversible. PMID:25697375

  16. IN VITRO PERCUTANEOUS ABSORPTION OF MONOSODIUM METHANERARSONATE (MSMA) AND DISODIUM METHANE-ARSONATE (DSMA) IN FEMALE B6C3F1 MICE

    EPA Science Inventory

    Percutaneous absorption of (14C] monosodium methanearsonate (MSMA) and disodium methanearsonate (DSMA) was investigated in female B6C3F1 mice from a variety of exposure conditions, including aqueous solution, solid compound, and soil. hese chemicals are the sodium salts of methan...

  17. PILOT SCALE TESTING OF MONOSODIUM TITANATE MIXING FOR THE SRS SMALL COLUMN ION EXCHANGE PROCESS - 11224

    SciTech Connect

    Poirier, M.; Restivo, M.; Williams, M.; Herman, D.; Steeper, T.

    2011-01-25

    The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and select actinides from Savannah River Site (SRS) Liquid Waste using an existing waste tank (i.e., Tank 41H) to house the process. Savannah River National Laboratory (SRNL) is conducting pilot-scale mixing tests to determine the pump requirements for suspending monosodium titanate (MST), crystalline silicotitanate (CST), and simulated sludge. The purpose of this pilot scale testing is to determine the requirements for the pumps to suspend the MST particles so that they can contact the strontium and actinides in the liquid and be removed from the tank. The pilot-scale tank is a 1/10.85 linear scaled model of SRS Tank 41H. The tank diameter, tank liquid level, pump nozzle diameter, pump elevation, and cooling coil diameter are all 1/10.85 of their dimensions in Tank 41H. The pump locations correspond to the proposed locations in Tank 41H by the SCIX program (Risers B5 and B2 for two pump configurations and Risers B5, B3, and B1 for three pump configurations). The conclusions from this work follow: (i) Neither two standard slurry pumps nor two quad volute slurry pumps will provide sufficient power to initially suspend MST in an SRS waste tank. (ii) Two Submersible Mixer Pumps (SMPs) will provide sufficient power to initially suspend MST in an SRS waste tank. However, the testing shows the required pump discharge velocity is close to the maximum discharge velocity of the pump (within 12%). (iii) Three SMPs will provide sufficient power to initially suspend MST in an SRS waste tank. The testing shows the required pump discharge velocity is 66% of the maximum discharge velocity of the pump. (iv) Three SMPs are needed to resuspend MST that has settled in a waste tank at nominal 45 C for four weeks. The testing shows the required pump discharge velocity is 77% of the maximum discharge velocity of the pump. Two SMPs are not sufficient to resuspend MST that settled under these

  18. Neural correlates of hyperalgesia in the monosodium iodoacetate model of osteoarthritis pain

    PubMed Central

    Abaei, Maryam; Sagar, Devi R; Stockley, Elizabeth G; Spicer, Clare H; Prior, Malcolm; Auer, Dorothee P

    2016-01-01

    Background The mechanisms driving osteoarthritic pain remain poorly understood, but there is increasing evidence for a role of the central nervous system in the chronification of pain. We used functional magnetic resonance imaging to investigate the influence of a model of unilateral knee osteoarthritis on nociceptive processing. Results Four to five weeks post intra-articular injection of monosodium iodoacetate (MIA, 1 mg) into the left knee, Sprague Dawley rats were anesthetized for functional magnetic resonance imaging studies to characterize the neural response to a noxious stimulus (intra-articular capsaicin injection). In a two-arm cross-over design, 5 µM/50 µl capsaicin was injected into either the left knee (n = 8, CAPS-MIA) or right control knee (n = 8, CAPS-CON), preceded by contralateral vehicle (SAL) injection. To assess neural correlates of mechanical hyperalgesia, hindpaws were stimulated with von Frey hairs (8 g: MIA; 15 g: control knee, based on behavioral withdrawal responses). The CAPS-MIA group exhibited significant activation of the periaqueductal gray, unilateral thalamus and bilateral mensencephalon, superior-colliculus, and hippocampus, with no significant activation in the other groups/conditions. Capsaicin injection increased functional connectivity in the mid-brain network and mediodorsal thalamic nucleus, hippocampus, and globus pallidus, which was significantly stronger in CAPS-MIA compared to CAPS-CON groups. Mechanical stimulation of the hyperalgesic (ipsilateral to MIA knee) and normalgesic (contralateral) hindpaws evoked qualitatively different brain activation with more widespread brainstem and anterior cingulate (ACC) activation when stimulating the hyperalgesic paw, and clearer frontal sensory activation from the normalgesic paw. Conclusions We provide evidence for modulation of nociceptive processing in a chronic knee osteoarthritis pain model with stronger brain activation and alteration of brain networks

  19. GLT-1: The elusive presynaptic glutamate transporter.

    PubMed

    Rimmele, Theresa S; Rosenberg, Paul A

    2016-09-01

    Historically, glutamate uptake in the CNS was mainly attributed to glial cells for three reasons: 1) none of the glutamate transporters were found to be located in presynaptic terminals of excitatory synapses; 2) the putative glial transporters, GLT-1 and GLAST are expressed at high levels in astrocytes; 3) studies of the constitutive GLT-1 knockout as well as pharmacological studies demonstrated that >90% of glutamate uptake into forebrain synaptosomes is mediated by the operation of GLT-1. Here we summarize the history leading up to the recognition of GLT-1a as a presynaptic glutamate transporter. A major issue now is understanding the physiological and pathophysiological significance of the expression of GLT-1 in presynaptic terminals. To elucidate the cell-type specific functions of GLT-1, a conditional knockout was generated with which to inactivate the GLT-1 gene in different cell types using Cre/lox technology. Astrocytic knockout led to an 80% reduction of GLT-1 expression, resulting in intractable seizures and early mortality as seen also in the constitutive knockout. Neuronal knockout was associated with no obvious phenotype. Surprisingly, synaptosomal uptake capacity (Vmax) was found to be significantly reduced, by 40%, in the neuronal knockout, indicating that the contribution of neuronal GLT-1 to synaptosomal uptake is disproportionate to its protein expression (5-10%). Conversely, the contribution of astrocytic GLT-1 to synaptosomal uptake was much lower than expected. In contrast, the loss of uptake into liposomes prepared from brain protein from astrocyte and neuronal knockouts was proportionate with the loss of GLT-1 protein, suggesting that a large portion of GLT-1 in astrocytic membranes in synaptosomal preparations is not functional, possibly because of a failure to reseal. These results suggest the need to reinterpret many previous studies using synaptosomal uptake to investigate glutamate transport itself as well as changes in glutamate

  20. Mood disorders: regulation by metabotropic glutamate receptors.

    PubMed

    Pilc, Andrzej; Chaki, Shigeyuki; Nowak, Gabriel; Witkin, Jeffrey M

    2008-03-01

    Medicinal therapies for mood disorders neither fully serve the efficacy needs of patients nor are they free of side-effect issues. Although monoamine-based therapies are the primary current treatment approaches, both preclinical and clinical findings have implicated the excitatory neurotransmitter glutamate in the pathogenesis of major depressive disorders. The present commentary focuses on the metabotropic glutamate receptors and their relationship to mood disorders. Metabotropic glutamate (mGlu) receptors regulate glutamate transmission by altering the release of neurotransmitter and/or modulating the post-synaptic responses to glutamate. Convergent biochemical, pharmacological, behavioral, and clinical data will be reviewed that establish glutamatergic neurotransmission via mGlu receptors as a biologically relevant process in the regulation of mood and that these receptors may serve as novel targets for the discovery of small molecule modulators with unique antidepressant properties. Specifically, compounds that antagonize mGlu2, mGlu3, and/or mGlu5 receptors (e.g. LY341495, MGS0039, MPEP, MTEP) exhibit biochemical effects indicative of antidepressant effects as well as in vivo activity in animal models predictive of antidepressant efficacy. Both preclinical and clinical data have previously been presented to define NMDA and AMPA receptors as important targets for the modulation of major depression. In the present review, we present a model suggesting how the interplay of glutamate at the mGlu and at the ionotropic AMPA and NMDA receptors might account for the antidepressant-like effects of glutamatergic- and monoaminergic-based drugs affecting mood in patients. The current data lead to the hypothesis that mGlu-based compounds and conventional antidepressants impact a network of interactive effects that converge upon a down regulation of NMDA receptor function and an enhancement in AMPA receptor signaling. PMID:18164691

  1. Circuit Mapping by UV Uncaging of Glutamate

    PubMed Central

    Shepherd, Gordon M. G.

    2014-01-01

    In laser photostimulation, small clusters of neurons in brain slices are induced to fire action potentials by focal glutamate uncaging, and synaptic connectivity between photoexcited presynaptic neurons and individual postsynaptic neurons is assessed by intracellular recording of synaptic events. With a scanner, this process can be repeated sequentially across a patterned array of stimulus locations, generating maps of neurons’ local sources of synaptic inputs. Laser scanning photostimulation (LSPS) based on patterned glutamate uncaging offers an efficient, quantitative, optical-electrophysiological way to map synaptic circuits in brain slices. PMID:22949715

  2. Molecular physiology of vesicular glutamate transporters in the digestive system

    PubMed Central

    Li, Tao; Ghishan, Fayez K.; Bai, Liqun

    2005-01-01

    Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system (CNS). Packaging and storage of glutamate into glutamatergic neuronal vesicles require ATP-dependent vesicular glutamate uptake systems, which utilize the electrochemical proton gradient as a driving force. Three vesicular glutamate transporters (VGLUT1-3) have been recently identified from neuronal tissue where they play a key role to maintain the vesicular glutamate level. Recently, it has been demonstrated that glutamate signaling is also functional in peripheral neuronal and non-neuronal tissues, and occurs in sites of pituitary, adrenal, pineal glands, bone, GI tract, pancreas, skin, and testis. The glutamate receptors and VGLUTs in digestive system have been found in both neuronal and endocrinal cells. The glutamate signaling in the digestive system may have significant relevance to diabetes and GI tract motility disorders. This review will focus on the most recent update of molecular physiology of digestive VGLUTs. PMID:15793854

  3. GLUTAMATE NEUROTOXICITY IN RAT AUDITORY SYSTEM: COCHLEAR NUCLEAR COMPLEX

    EPA Science Inventory

    In other systems such as the hypothalamus and hippocampus, it has been shown that cells postsynaptic with respect to glutamatergic inputs degenerate when exposed to large doses of glutamate ("glutamate neurotoxicity"). e have shown that large doses of glutamate administered intra...

  4. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  5. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  6. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  7. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  8. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride. (b) (c) Limitations, restrictions, or explanation....

  9. Circuit mapping by ultraviolet uncaging of glutamate.

    PubMed

    Shepherd, Gordon M G

    2012-09-01

    In laser photostimulation, small clusters of neurons in brain slices are induced to fire action potentials by focal glutamate uncaging, and synaptic connectivity between photoexcited presynaptic neurons and individual postsynaptic neurons is assessed by intracellular recording of synaptic events. With a scanner, this process can be repeated sequentially across a patterned array of stimulus locations, generating maps of neurons' local sources of synaptic inputs. Laser scanning photostimulation (LSPS) based on patterned glutamate uncaging offers an efficient, quantitative, optical-electrophysiological way to map synaptic circuits in brain slices. The efficacy of glutamate-based photostimulation for circuit mapping (in contrast to electrical stimulation) derives from the ability to stimulate neurons with high precision and speed, and without stimulating axons of passage. This protocol describes the components, assembly, and operation of a laser scanning microscope for ultraviolet (UV) uncaging, along with experimental methods for circuit mapping in brain slices. It presents a general approach and a set of guidelines for quantitative circuit mapping using "standard" LSPS methods based on single-photon glutamate uncaging using a UV laser, a pair of scanning mirror galvanometers, a patch-clamp setup, and open-source data acquisition software. PMID:22949715

  10. L-glutamate Receptor In Paramecium

    NASA Astrophysics Data System (ADS)

    Bernal-Martínez, Juan; Ortega-Soto, Arturo

    2004-09-01

    Behavioral, electrophysiological and biochemical experiments were performed in order to establish the presence of a glutamate receptor in the ciliate Paramecium. It was found that an AMPA/KA receptor is functionally expressed in Paramecium and that this receptor is immunologically and fillogenetically related to the AMPA/KA receptor present in vertebrates.