Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GLUTAMIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1981

Influence of hyperprolactinemia induced by adenopituitary transplantation under the kidney capsule on the glutamic acid decarboxylase activity in various brain regions.

Glutamic acid decarboxylase activity was assayed in rat substantia nigra, corpus striatum, medial basal hypothalamus and cerebellum under conditions of hyperprolactinemia induced by transplantation of adenopituitary under the kidney capsule. The results indicate that hyperprolactinemia induces a slight increase in the glutamic acid decarboxylase activity of substantia nigra and medial basal hypothalamus and a more evident increase at striatal level. No change was observed in the cerebellum.

Animals↗
PubMed1980

Alterations in the compartmentalized metabolism of glutamic acid with changed cerebral conditions.

Data obtained from combined determinations of the nervous tissue content of glutamic acid, taurine and glutamine were examined in terms of the well established concept of a compartmentalized metabolism for glutamic acid. Three different situations associated with altered cortical conditions were studied: cortical hyperexcitability induced by cobalt epilepsy (mouse); chronic stimulation of the optic tectum by light adaptation (fish); and anatomic alteration of the optic tectum following unilateral enucleation (fish). All 3 situations appear to cause a reduction in the ability of glial elements to capture free glutamic acid released from neuronal structures. However, the underlying causes for such an insufficiency seem to differ in each instance. In epilepsy the release of glutamic acid and taurine exceeds the glial capture rate; during chronic stimulation of a normal cortex a diminished glial uptake rate for both amino acids seems apparent; anatomical degenerative changes seem to diminish especially the glutamine retention capacity of the cortex, possibly in combination with a reduced glial taurine uptake.

Animals↗
PubMed1983

Incorporation of glutamic acid into protein by a soluble system.

A heat-labile, non-dialyzable factor(s) in soluble fractions from Escherichia coli strains and Bacillus subtilis was found to incorporate the radioactivity of [14C]glutamic acid into 95 degrees C CCl3COOH-insoluble fraction. Incorporation catalyzed by a partially purified factor from E. coli B required ATP, Mg2+, tRNA, casein, carbonate, and 2-mercaptoethanol. A mixture of nineteen amino acids other than glutamic acid had no effect on the incorporation. Heparin, spermine and monovalent cations were inhibitory. Incorporation proceeded via glutamyl-tRNA. The incorporation from [14C]glutamyl-tRNA required Mg2+, casein, carbonate, and 2-mercaptoethanol, and there was no incorporation from [14C]aspartyl-tRNA. The reaction product was identified as protein. The incorporated moiety was the glutamyl moiety of glutamic acid and it retained a free alpha-amino group in the product protein. The incorporating factor of E. coli B was demonstrated to be glutamyl-tRNA synthetase.

Bacillus subtilis↗
PubMed2000

[Effect of Jiunaoning injection on overload of intracellular free calcium of cerebral cortex induced by glutamic acid or 5-hydroxytryptamine in fetal rats].

OBJECTIVE: To explore the effect of Jiunaoning Injection (JNNI) on overload of intracellular free calcium of cerebral cortex induced by glutamic acid or 5-hydroxytryptamine (5-HT) in fetal rats. METHODS: Double wavelength spectrofluorometer with Fura-2/AM as the fluorescence indicator for intracellular calcium ions ([Ca2+]i) was used to measure the changes of [Ca2+]i in instantly separated cortical nerve cells of newborn rats affected by glutamic acid or 5-HT, as well as the interference of JNNI on it. RESULTS: Glutamic acid or 5-HT could elevate the intracellular [Ca2+]i dose-dependently and induce [Ca2+]i overload. JNNI could restrain the elevation markedly so as to protect the neurocytes from injury of glutamic acid and 5-HT. CONCLUSION: The therapeutic effect of JNNI in treating apoplexy is related with its action in suppressing the toxic substances as glutamic acid and 5-HT, restraining the opening of receptor dependent calcium channel, reducing the external cellular calcium influx and preventing the calcium overload effectively.

Animals↗
PubMed1987

Effect of hyperoxia on glutathione levels and glutamic acid uptake in endothelial cells.

Intracellular glutathione was increased by 80% after exposure of bovine pulmonary arterial endothelial cells to 80% O2 (hyperoxia) for 24 h. No change in glutathione occurred in cells exposed to hypoxia (3% O2) for a corresponding period of time. The rate of uptake of [3H]glutamic acid also increased by 35-55% after 24 h of exposure of cells to hyperoxia, whereas exposure to hypoxia had no effect on the [3H]glutamic acid uptake. The increase in glutamic acid uptake reflected a specific effect on amino acid transport systems rather than a change in cell membrane permeability. The major portion of the increased uptake was inhibited by the elimination of sodium and the addition of the competitive inhibitor, cystine, to the incubation medium. Thus increases in glutamic acid uptake parallel increases in cellular glutathione, and glutamic acid may be a regulating factor in the increase in glutathione after exposure to hyperoxia.

Amino Acids↗
PubMed1994

The heterogeneity of whole islet cell cytoplasmic antibodies evidenced by absorption test with glutamic acid decarboxylase.

A recent report identified two islet cell cytoplasmic antibody subclasses using an immunohistochemical method. The islet cell cytoplasmic antibody subclass which reacts with only Beta-cells was termed 'Beta-cell islet cell cytoplasmic antibodies' and another islet cell cytoplasmic antibody subclass which reacts with Beta and non-Beta cells was called 'whole islet cell cytoplasmic antibodies'. The whole islet cell cytoplasmic antibody reactivity with pancreatic islets has been shown not to be abolished by pre-incubation with rat brain homogenate. In this study, we examined the inhibitory effect of purified glutamic acid decarboxylase to islet cell cytoplasmic antibody reactivity among whole islet cell cytoplasmic antibodies and assessed the heterogeneity of islet cell cytoplasmic antibodies. Auto-antibodies to 64,000 Mr islet cell protein (64 K antibodies) were also determined by conventional method. Sera from 17 Type 1 (insulin-dependent) diabetic patients containing whole islet cell cytoplasmic antibodies with more than 20 Juvenile Diabetes Foundation units were used. In 11 (78.6%) of 14 sera positive for 64 K antibodies, the reactivity of islet cell cytoplasmic antibodies was markedly blocked by pre-incubation with purified glutamic acid decarboxylase. In contrast, none of the 64 K antibody-negative sera were blocked. All of the patients showed similar clinical characteristics regardless of the inhibitory effect of glutamic acid decarboxylase on islet cell cytoplasmic antibodies, except for islet cell cytoplasmic antibody titer and glutamic acid decarboxylase antibody titer. The mean log 2 islet cell cytoplasmic antibody titer was 2.4 +/- 0.6 (mean +/- SD) JDF unit in the 'markedly blocked' group and 1.6 +/- 0.3 (mean +/- SD) in the 'never blocked' group. The islet cell cytoplasmic antibody titer was significantly higher (P < 0.05) in the former, and the mean glutamic acid decarboxylase antibody titer was 624 +/- 127.0 (mean +/- SE) units in the 'markedly blocked' group and 127 +/- 55.5 (mean +/- SE) in the 'never blocked' group. The glutamic acid decarboxylase antibody titer was also significantly higher (P < 0.05) in the former. We demonstrated here that some whole islet cell cytoplasmic antibodies are absorbed by purified glutamic acid decarboxylase, suggesting heterogeneity of islet cell cytoplasmic antibodies among the 64 K glutamic acid decarboxylase antibody positive group.

Absorption↗
PubMed1984

[Perissodactyla: the primary structure of hemoglobins from the lowland tapir (Tapirus terrestris): glutamic acid in position 2 of the beta chains].

The hemoglobins from a lowland tapir (Tapirus terrestris) were analysed and the complete primary structure is described. The globin chains were separated on CM cellulose column in 8M urea and the amino-acid sequences were determined in the liquid phase sequenator. The results show that globin consists of two alpha chains (alpha I and alpha II) and beta major and beta minor components. The alpha chains differ only at one position: alpha I contains aspartic acid and alpha II glycine. The beta chains are heterogeneous: aspartic and glutamic acid were found at position beta 21 and beta 73 of the beta major components and asparagine and serine at position beta 139. In the beta minor components four positions were found with more than one amino acid, namely beta 2, beta 4, beta 6 and beta 56. The sequences are compared with those of man, horse and rhinoceros. Four residues of horse methemoglobin, which are involved in the alpha 1 beta 1 contacts are substituted in tapir hemoglobins. In the alpha chains: alpha 107(G14)Ser----Val, alpha 111-(G18) Val----Leu, alpha 115(GH3) Asn----Asp or Gly; in the beta chains: beta 116(G18) Arg----Gln. The amino acid at beta 2 of the major components is glutamic acid while glutamine and histidine are found in the minor components. Although glutamic acid, a binding site for ATP, does not interact with 2,3-bisphosphoglycerate, glutamine and histidine in the minor components are responsible for the slight effect of 2,3-bisphosphoglycerate on tapir hemoglobin.

Amino Acid Sequence↗
PubMed1978

Glutamine and glutamic acid uptake by rat renal brushborder membrane vesicles.

Glutamine uptake by rat renal brushborder vesicles occurred via two distinct saturable processes with Km values of 0.145 and 8.5 mM which were stimulated by both ionic and sodium gradients with a pH optimum of 6.8--7.1. Glutamic acid uptake also occurred by a two-component system with Km values of 0.016 and 3.60 mM. Both components were stimulated specifically by a sodium gradient. The low Km system for glutamic acid had a pH optimum of 7.2--7.4. Glutamine entry at 0.06 mM was inhibited by a variety of amino acids at 3 mM, including dibasic amino acids, glycine, valine, and phenylalanine. Glutamic acid entry at 0.06 mM was inhibited 20--30% by 3 mM phenylalanine, valine, alpha-aminoisobutyric acid, and glutamine. No metabolic alteration of glutamic acid was observed on incubation with membrane vesicles, but glutamine was significantly hydrolyzed to glutamic acid upon prolonged incubation. Hydrolysis of glutamine was negligible at 15 sec incubation which was employed for measurement of initial rate of entry. These studies provide support for the existence of an uptake system in the brushborder of the renal proximal tubule cell capable of handling the reabsorption of glutamine normally present in glomerular filtrate.

Amino Acids↗
PubMed1984

Distribution of glycine, gamma-aminobutyric acid, glutamate decarboxylase, and gamma-aminobutyric acid transaminase in rabbit and mudpuppy retinas.

The distributions of glycine, gamma-aminobutyric acid (GABA), glutamate decarboxylase (EC 4.1.1.15), and GABA transaminase (EC 2.6.1.19) were determined in rabbit and mudpuppy retinas. In both species, peak levels of the amino acids and the enzymes occurred in the inner plexiform layer. Glutamate decarboxylase was almost entirely confined to the inner plexiform layer. Determinations were also made of the GABA content of 107 individual putative amacrine cell somas from mudpuppy retina. About 30% of those somas were found to have high endogenous GABA levels.

4-Aminobutyrate Transaminase↗
PubMedDate not supplied

[Human blood glutamic acid in exposure to elevated ammonia levels in the gaseous environment].

Amino acid metabolism of men kept in a enclosed environment was investigated. A high concentration of ammonia produced a specific redistribution of free amino acids in plasma with the content of glutamic acid increasing by the end of study. The estimates of glutamic acid in blood can be used for assessing maximally allowable concentrations of ammonia in enclosed environments.

Amino Acids↗
PubMed2006

Stereological estimates of the basal forebrain cell population in the rat, including neurons containing choline acetyltransferase, glutamic acid decarboxylase or phosphate-activated glutaminase and colocalizing vesicular glutamate transporters.

The basal forebrain (BF) plays an important role in modulating cortical activity and influencing attention, learning and memory. These activities are fulfilled importantly yet not entirely by cholinergic neurons. Noncholinergic neurons also contribute and comprise GABAergic neurons and other possibly glutamatergic neurons. The aim of the present study was to estimate the total number of cells in the BF of the rat and the proportions of that total represented by cholinergic, GABAergic and glutamatergic neurons. For this purpose, cells were counted using unbiased stereological methods within the medial septum, diagonal band, magnocellular preoptic nucleus, substantia innominata and globus pallidus in sections stained for Nissl substance and/or the neurotransmitter enzymes, choline acetyltransferase (ChAT), glutamic acid decarboxylase (GAD) or phosphate-activated glutaminase (PAG). In Nissl-stained sections, the total number of neurons in the BF was estimated as approximately 355,000 and the numbers of ChAT-immuno-positive (+) as approximately 22,000, GAD+ approximately 119,000 and PAG+ approximately 316,000, corresponding to approximately 5%, approximately 35% and approximately 90% of the total. Thus, of the large population of BF neurons, only a small proportion has the capacity to synthesize acetylcholine (ACh), one third to synthesize GABA and the vast majority to synthesize glutamate (Glu). Moreover, through the presence of PAG, a proportion of ACh- and GABA-synthesizing neurons also has the capacity to synthesize Glu. In sections dual fluorescent immunostained for vesicular transporters, vesicular glutamate transporter (VGluT) 3 and not VGluT2 was present in the cell bodies of most PAG+ and ChAT+ and half the GAD+ cells. Given previous results showing that VGluT2 and not VGluT3 was present in BF axon terminals and not colocalized with VAChT or VGAT, we conclude that the BF cell population influences cortical and subcortical regions through neurons which release ACh, GABA or Glu from their terminals but which in part can also synthesize and release Glu from their soma or dendrites.

Acetylcholine↗
PubMed1981

The failure of glutamic acid to protect the rat embryo against the action of trypan blue.

The effect of L-glutamic acid on the embryolethal and teratogenic action of trypan blue was investigated in Wistar albino rats. L-glutamic acid was either incorporated into the diet, from gestation day 2 to day 20, or suspended in sesame oil and administered by gavage, from gestation day 6 to day 10. The day of finding sperm in the vaginal smear was designated day 0 of pregnancy. A teratogenic dose of trypan blue was injected at day 8 of pregnancy, either intraperitoneally (14 mg/kg maternal body weight) or subcutaneously (160 mg/kg). The amount of glutamic acid consumed, after the injection of trypan blue, ranged from 600 to 1,500 mg/rat/day. Pregnancy was terminated at day 20, and the fetuses were recovered and examined. Glutamic acid failed consistently to protect the rat embryo against the lethal and teratogenic action of trypan blue. These results are in contrast to those obtained in mice. the administration of sesame oil alone was found to cause embryonic death but not malformations.

Abnormalities, Drug-Induced↗
PubMed1984

Glutamic acid modification of vincristine toxicity.

The principal limiting feature of the antitumor agent, vincristine, in the clinic has been neurotoxicity; there are no known agents which can routinely prevent or decrease this side effect. Glutamic acid in laboratory and clinical investigations in the early 1960s was found to antagonize vinblastine, another clinically useful vinca alkaloid. Glutamic acid 250 mg/kg/d i.p. was given to normal mice treated with repetitive doses of vincristine 1.5 mg/kg every other day. When glutamic acid was given both before and during vincristine administration, it produced a 49-79% increase in survival compared to control mice receiving vincristine only (p less than 0.01). Other schedules of glutamic acid administration were ineffective. Also, there appeared to be a delay in development of neurotoxic manifestations (toe-walking gait) but the results were not as consistent as the improvement in survival. Glutamic acid given to tumor-bearing mice (P-388 and P-1534 murine leukemia) did not inhibit the antitumor effect of vincristine-induced host toxicity in a schedule-dependent fashion without inhibition of the antitumor effect of vincristine.

Animals↗
PubMed1998

ATP-dependent inactivation of Escherichia coli gamma-glutamylcysteine synthetase by L-glutamic acid gamma-monohydroxamate.

Incubation of Escherichia coli gamma-glutamylcysteine synthetase with L-glutamic acid gamma-monohydroxamate and ATP caused slow but irreversible inhibition of the enzyme, and more than 90% activity was lost in three days. The enzyme was not inactivated when ATP was absent or L-aspartic acid beta-monohydroxamate was substituted for L-glutamic acid gamma-monohydroxamate, suggesting that the inactivation process reflected a mechanism-based reaction of L-glutamic acid gamma-monohydroxamate and ATP.

Adenosine Triphosphate↗
PubMed2006

A glutamic acid 3-methyltransferase encoded by an accessory gene locus important for daptomycin biosynthesis in Streptomyces roseosporus.

In many peptide antibiotics, modified amino acids are important for biological activity. The amino acid 3-methyl-glutamic acid (3mGlu) has been found only in three cyclic lipopeptide antibiotics: daptomycin and the A21978C family produced by Streptomyces roseosporus, calcium-dependent antibiotic produced by Streptomyces coelicolor and A54145 produced by Streptomyces fradiae. We studied the non-ribosomal peptide synthetase genes involved in A21978C biosynthesis and the downstream genes, dptG, dptH, dptI and dptJ predicted to encode a conserved protein of unknown function, a thioesterase, a methyltransferase (MTase) and a tryptophan 2,3-dioxygenase respectively. Deletion of dptGHIJ reduced overall lipopeptide yield and led to production of a series of novel A21978C analogues containing Glu12 instead of 3mGlu12. Complementation by only dptI, or its S. coelicolor homologue, glmT, restored the biosynthesis of the 3mGlu-containing compounds in the mutant. Compared with A21978C, the Glu12-containing derivatives were less active against Staphylococcus aureus. Further genetic analyses showed that members of the dptGHIJ locus cooperatively contributed to optimal A21978C production; deletion of dptH, dptI or dptJ genes reduced the yield significantly, while expression of dptIJ or dptGHIJ from the strong ermEp* promoter substantially increased lipopeptide production. The results indicate that these genes play important roles in the biosynthesis of daptomycin, and that dptI encodes a Glu MTase.

Amino Acid Motifs↗
PubMed1976

Effects of intraventricular glutamic acid on the acquisition, performance, and extinction of an operant response, and on general activity.

This study was designed to investigate the effects of intracerebral injections of glutamic acid on acquisition and extinction of a bar-press response, performance of that response, and behavior activity. Nineteen food-deprived rats bearing chronic ventricular cannulae were tested in operant conditioning chambers or in an open field. Just prior to each testing session each animal was injected intraventricularly with 10 mul of either normal or acidified saline solution (control groups), or 10 mul of 100 mMol glutamic acid solution. Acquisition of the bar-pressing response by the glutamic acid group was significantly retarded as compared to the control groups, and the responding of the glutamic acid group was suppressed during the beginning of the first few sessions of testing on a fixed-interval schedule and during extinction. Other behavioral measures, such as operant level, performance of the response on a continuous schedule, performance on fixed-interval and extinction schedules except during the start of the first few sessions, and behavioral activity, were either unaffected or only slightly affected. It is concluded that interference with the normal neurophysiological activity of glutamic acid in the central nervous system interferes with learning and suppresses behavioral output in certain situations.

Animals↗