Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alcoholic hepatitis is defined by histological findings, i.e. Mallory bodies, necrosis and polynuclear infiltration. It may be accompanied by steatosis and more or less advanced fibrosis. The clinical picture is variable, ranging from a total absence of symptoms to high fever, jaundice and encephalopathy. Laboratory findings reveal high polynuclear white cell counts, SGOT (but not SGPT) and glutamate dehydrogenase levels. The prognosis varies according to the series studied. The pathogenesis is unclear but cellular and humoral immunity mechanisms may play a role. Therapeutic possibilities are limited, corticosteroids only being useful in very serious cases. Alcoholic hepatitis is not a nosological entity but an acute inflammatory reaction of the liver due to cell necrosis caused by alcohol, and can therefore occur at any stage of alcoholic liver.
Schweiz Med Wochenschr 1980 Sep 20
PMID:[Alcoholic hepatitis]. 610 66

Aspartate transaminase, alanine transaminase, glutamate dehydrogenase, arginase, serine dehydratase, tyrosine transaminase, glutamine synthetase, glutaminase and adenylate deaminase activities were measured in crude homogenates of 12, 19 and 21-day rat placentae. There is a considerable quantitative importance in enzymes able to produce free ammonia, such as adenylate deaminase and glutamate dehydrogenase, activity that progressively decrease with the age of placenta. The glutamine synthetase and tyrosine transaminase activities increase with age, while serine dehydratase decreases considerably and aspartate and alanine transaminase do not change practically. Arginase shows a maximum at 19, with lower 12 and 21-day activities. No measurable glutaminase activity has been found. The possible implications of the enzymes studied upon the ammonia-producing activity of rat placenta are discussed together with the relative decreasing role of placenta for the overall metabolic activity of the foetus, especially during the last phases of its development.
Eur J Biochem 1980 Sep
PMID:Activities of enzymes involved in amino-acid metabolism in developing rat placenta. 610 12

The leucine analog beta-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid (BCH) activates glutamate dehydrogenase [L-glutamate:NAD+ oxidoreductase (deaminating), EC 1.4.1.2] in pancreatic islet homogenates. In intact islets, BCH increased the islet content or output of NH4+, 2-ketoglutarate, malate, pyruvate, and alanine. BCH caused a dose-related increase in 14CO2 output from islets prelabeled with L-[U-14C]glutamine. BCH increased the islet content of ATP and stimulated both 45Ca net uptake and insulin release. The capacity of seven distinct amino acids to activate glutamate dehydrogenase tightly correlated with their ability to augment 14CO2 output from islets prelabeled with [U-14C]-glutamine and to stimulate insulin release in the presence of L-glutamine. The activation of glutamate dehydrogenase by BCH may thus account for the insulin-releasing capacity of the leucine analog.
Proc Natl Acad Sci U S A 1981 Sep
PMID:Stimulation of pancreatic islet metabolism and insulin release by a nonmetabolizable amino acid. 611 57

The formation of GABA from L-glutamate was investigated in homogenates of rat brain, liver, and kidney, using highly purified [14C]-L-glutamic acid as substrate and a thin-layer chromatographic separation of products. In agreement with other workers, liberation of [14C]-CO2 was found to be stoichiometric with GABA formation in brain homogenates, but not in liver or kidney extracts. Subcellular fractionation and dialysis experiments suggested that most of the GABA synthesis in these peripheral tissues, unlike brain, does not occur via a direct decarboxylation of glutamate and requires one or more cofactors other than pyridoxal phosphate. NAD stimulated GABA formation in dialyzed extracts, and inhibition of GABA-transaminase, both in vitro and in vivo, caused marked inhibition of GABA formation from glutamate in peripheral extracts. Although a very low GAD activity in liver and kidney cannot be excluded, these experiments suggest a major pathway from glutamate to GABA in these homogenates which includes (1) conversion of glutamate to alpha-ketoglutarate by glutamate dehydrogenase or transaminases, (2) conversion of alpha-ketoglutarate to succinic semialdehyde, and (3) formation of GABA from succinic semialdehyde and glutamate by GABA-transaminase.
Mol Cell Biochem 1981 Sep 25
PMID:Glutamate as a precursor of GABA in rat brain and peripheral tissues. 611 23

Acetylcholinesterase, glutamine synthetase, acid phosphatase and glutamate dehydrogenase activity in brain and cholinesterase activity in blood were investigated in mice exposed to 170 p.p.m. trichloroethylene (TCE) during 30 days. The neuronal enzymes remained unaffected which suggests that no general damage occurred to either the glia or the nerve cell populations. In accordance with this no effect was seen on acid phosphatase. In contrast, plasma butyrylcholinesterase increased twofold in exposed male mice while it was unaffected in females. Liver weight in males and females increased with a factor of 1.5 and 1.9, respectively.
Acta Pharmacol Toxicol (Copenh) 1981 Sep
PMID:Neurotransmitter metabolizing enzymes and plasma butyrylcholinesterase in mice exposed to trichloroethylene. 612 57

The effects of transcription and translation inhibitors on NADP-glutamate dehydrogenase and glutamine synthetase synthesis in nitrogen-starving Ankistrodesmus braunii cells have been studied. Considering the results obtained one can suggest that both enzymes are coded in a chloroplast genome and that during nitrogen starvation specific mRNA's are partly transferred from chloroplast into cytoplasm and can be translated there on 80S ribosomes.
Mol Cell Biochem 1982 Sep 03
PMID:The role of chloroplast and cytoplasm in the NADP-glutamate dehydrogenase and glutamine synthetase synthesis in Ankistrodesmus cells. 612 70

The NAD+-specific glutamate dehydrogenase from Peptostreptococcus asaccharolyticus follows Michaelis-Menten kinetics in contrast to the enzyme from several other sources, and thus gives linear double-reciprocal plots of initial-rate data. The initial-rate parameters have been determined for this bacterial dehyrogenase in the direction of oxidative deamination. The use of alternative coenzymes leads to some conclusions about the order of substrate addition. An investigation of the pH dependence of this reaction reveals that the binding of oxidised coenzyme is independent of pH over the range 6-9. The kinetic data are consistent with an ordered addition of coenzyme prior to glutamate, the reverse of the mechanism derived with ox glutamate dehydrogenase in the presence of ADP.
Eur J Biochem 1984 Sep 17
PMID:A kinetic study of the oxidative deamination of L-glutamate by Peptostreptococcus asaccharolyticus glutamate dehydrogenase using a variety of coenzymes. 614 40

The effect of pyridoxal 5'-phosphate on the activity of ox liver glutamate dehydrogenase towards different amino acid substrates was investigated. Both alanine and glutamate activities decreased steadily in the presence of pyridoxal 5'-phosphate. The alanine/glutamate activity ratio increased as a function of inactivation by pyridoxal 5'-phosphate, indicating that glutamate activity is lost more rapidly than alanine activity. A mixture of NADH, GTP and 2-oxoglutarate completely protected the alanine and glutamate activities against inactivation by pyridoxal 5'-phosphate. The activity of glutamate dehydrogenase towards glutamate and leucine decreased steadily in a constant ratio in the presence of pyridoxal 5'-phosphate. The effect of leucine on the alanine and glutamate activities as a function of inactivation by pyridoxal 5'-phosphate was studied. The results are interpreted to suggest that the subunits of glutamate dehydrogenase hexamer are kinetically non-equivalent with regard to activity towards the two monocarboxylic amino acids as well as glutamate, and that all three substrates share the same active centre. However, leucine is also able to bind at a separate regulatory site.
Biochem J 1984 Sep 15
PMID:Ox liver glutamate dehydrogenase. The use of chemical modification to study the relationship between catalytic sites for different amino acid substrates and the question of kinetic non-equivalence of the subunits. 614 32

This study examines the structural relationship of mitochondria and the endoplasmic reticulum in liver. Livers of rat and Japanese quail were homogenized and fractionated in media of 0.25 M-sucrose, either 5mM or 50 mM in sodium Hepes [4-(2-hydroxyethyl)-1-piperazine-ethanesulphonic acid], pH 7.4 (2.2 mM or 22 mM in Na respectively), designated here as low- and high-salt media. Three particulate fractions were prepared by sequential centrifugation. A nuclear pellet sedimenting at 300 g was obtained as described by Shore & Tata [(1977) J. Cell Biol. 72, 714-725], and from the resulting supernatant thereof a low-speed pellet (1100-1500 g) and a high-speed pellet (8000-10 000 g) were prepared. In the low-salt medium the yields of mitochondrial matrix enzymes (citrate synthase, glutamate dehydrogenase, ornithine carbamoyltransferase) and their specific activities in the low-speed pellet were over twice those in the high-speed pellet. In the high-salt medium the yield of matrix enzymes was 4-5 times, and the specific activities were up to 3 times, higher in the low-speed pellet than in the high-speed pellet. Oxygen uptake and respiratory control ratio were also much higher in the low-speed pellets in both media. Some 50-65% of the microsomal marker enzyme glucose 6-phosphatase was in the supernatant from the high-speed pellet, and the rest sedimented with the mitochondria. Repeated washing with the high-salt medium removes only a limited amount of reticulum. Washing with salt-free sucrose removes most of the reticulum, but a fraction remains strongly bound to mitochondria. Homogenates from quail and rat liver were fractioned isopycnically on Percoll gradients in either 0.25 M-sucrose or 0.25 M-sucrose/50 mM-sodium Hepes. Up to five particulate bands were separated and assayed. Mitochondria were present in two to three bands and were associated with endoplasmic reticulum. As seen in the phase-contrast microscope the mitochondria prepared in the low-salt medium consist of separate organelles. In the high-salt medium the mitochondria appear as chains of from three to ten organelles not touching each other. On addition of univalent ions at concentrations above 20 mM, the mitochondria aggregate into chains, and at higher ionic strength larger multidimensional aggregates are formed. The dispersion and aggregation of mitochondria are reversible. Negatively stained electron micrographs reveal a branched mitochondrial structure, with mitochondria held together by strands of reticulum.(ABSTRACT TRUNCATED AT 400 WORDS)
Biochem J 1983 Sep 15
PMID:Mitochondrial-reticular cytostructure in liver cells. 635 78

Affinity precipitation, a novel technique closely related to immunoprecipitation and affinity chromatography, has been evaluated in systems comprised of dehydrogenases and a bifunctional NAD derivative, Bis-NAD. Lactate dehydrogenase and glutamate dehydrogenase were easily precipitated whereas yeast alcohol dehydrogenase required the presence of salt to enhance the affinity precipitation. Liver alcohol dehydrogenase did not precipitate, probably because most of the affinity complexes formed were composed of only two enzyme molecules. Affinity precipitation was carried out on a preparative scale for the isolation of ox heart lactate dehydrogenase from a crude extract. The yield and purity of the enzyme and the general properties of the procedure are considered very satisfactory.
Anal Biochem 1983 Sep
PMID:Affinity precipitation of dehydrogenases. 635 87


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