Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.3.11 (glutamate dehydrogenase)
 4,437 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of repeated administration of benthiocarb on the nitrogen metabolism of hepatic and neuronal systems have been studied. Repeated benthiocarb treatment was associated with significant decrease in proteins with a concomitant increase in free amino acids (FAA) and specific activity levels of proteases suggesting impaired protein synthesis or elevated proteolysis. The glycogenic aminotransferases showed a significant elevation in both the tissues indicating high feeding of ketoacids into oxidative pathway for efficient operation of TCA cycle to combat energy crisis during induced benthiocarb stress. However, the activity levels of branched-chain aminotransferases decreased suggesting their reduced contribution of intermediates to TCA cycle. A comparative evaluation of the activity levels of ammonogenic enzymes, AMP deaminase, adenosine deaminase and glutamate dehydrogenase (GDH) indicated that ammonia was mostly contributed by nucleotide deamination rather than by oxidative deamination. GDH exhibited reduced activity due to low availability of glutamate. In accordance with increased levels of urea, the activity levels of arginase, a terminal enzyme of urea cycle was increased suggesting increased urea cycle operation in order to combat the increased ammonia content. As the presence of urea cycle in the brain is rather doubtful, the conversion of ammonia to glutamine for the synthesis of GABA is envisaged in brain whereas in liver, excess ammonia was converted to urea through ornithine-arginine reacting system. The increased glutaminase activity observed during benthiocarb intoxication is accounted for counteracting acidosis or maintenance of metabolic homeostasis. Arginase, a terminal enzyme of ornithine cycle showed increased activity denoting the efficient potentiality of tissues to avert ammonia toxicity. The changes observed in tissues of rat administered with benthiocarb reflects a shift in nitrogen metabolism for efficient mobilization of end products of protein catabolism.
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PMID:Perturbations in nitrogen metabolism of brain and liver of rat following repeated benthiocarb administration. 266 46

The activities of aspartate and alanine transaminase, serine dehydratase, arginase, glutamate dehydrogenase, adenylate deaminase and glutamine synthetase were determined in the stomach and small intestine of developing rats. Despite the common embryonic origin of the intestine and stomach, their enzymes showed quite different activity levels and patterns of development, depending on their roles. Most enzyme activities were low during late intrauterine life and after birth, attaining adult levels with the change of diet at weaning. No arginase activity was found in the stomach and no changes were detected in adenylate deaminase in the stomach or intestine throughout the period studied. Alanine transaminase, serine dehydratase and, to some extent, glutamine synthetase levels, significantly higher in late intrauterine life, decreased after birth, suggesting that the foetal stomach has a transient ability to handle amino acids.
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PMID:Activities of amino acid metabolizing enzymes in the stomach and small intestine of developing rats. 286 86

Many different serum biochemical tests can help in the diagnosis of liver disturbances in ruminants. The best tests for hepato-cellular damage are the measurement of enzymes such as glutamate dehydrogenase, sorbitol dehydrogenase and, if available, arginase or ornithine carbamoyl transferase. Disturbances of biliary function can be investigated through the measurement of so-called "cholestasis enzyme markers" such as gammaglutamyl transferase or alkaline phosphatases; bilirubin and bile salts can also be helpful. Liver insufficiency can be approached through the measurement of serum albumin, fibrinogen and coagulation tests whereas inflammative and inductive processes are difficult to investigate. Moreover, liver clearances (bromosulfonephtalein or indocyanine green) can provide useful data about whole liver function.
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PMID:[Biochemical semiology of the liver in ruminants]. 287 2

There was a nil arginase and serine dehydratase activities in interscapular brown adipose tissue, but the activity of adenylate deaminase, glutamine synthetase, glutamate dehydrogenase and the aspartate, alanine and branched chain amino acid transaminases was higher than those of white adipose tissue; the differences were diminished when expressed per unit of protein weight. Brown adipose tissue enzyme activities were in a range between those of liver and muscle. The high amino acid handling capabilities, together with its physiological role, suggest that brown adipose tissue can metabolize significant amounts of amino acids, its enzyme pattern being different both from white adipose tissue, as well as of liver and muscle.
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PMID:Activities of enzymes of amino acid metabolism in rat brown adipose tissue. 287 38

Mutations in the GLN3 gene prevented a normal increase in the NAD-glutamate dehydrogenase and glutamine synthetase levels in glutamate-grown Saccharomyces cerevisiae cells, whereas mutations in the URE2 gene resulted in high levels of these enzymes in glumate- and glutamine-grown cells. A ure2 gln3 double mutant had low levels of glutamate dehydrogenase and glutamine synthetase in cells grown on glutamate and glutamine; thus, gln3 mutations were epistatic to the ure2 mutations. The results suggest that the GLN3 product is capable of promoting increases in enzyme levels in the absence of a functional URE2 product and that the URE2 product antagonizes the GLN3 product. The URE2 and GLN3 genes were also found to regulate the level of arginase activity. This regulation is completely independent of the regulation of arginase by substrate induction. The activities of glutamate dehydrogenase, glutamine synthetase, and arginase were higher in cells grown on glutamate as the nitrogen source than they were in cells grown under a nitrogen-limiting condition. It had previously been shown that the levels of these enzymes can be increased by glutamine deprivation. We propose that the URE2-GLN3 system regulates enzyme synthesis, in response to glutamine and glutamate, to adjust the intracellular concentration of ammonia so as to maintain glutamine at the level required for optimal growth.
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PMID:Regulation of nitrogen assimilation in Saccharomyces cerevisiae: roles of the URE2 and GLN3 genes. 289 26

A spectrophotometric method for the determination of arginase (EC 3.5.3.1) is presented. Arginase is coupled to urease and glutamate dehydrogenase and the decrease in absorbance at 340 nm due to the oxidation of NADPH is followed. The method is rapid, is sensitive, is economical and permits continuous monitoring. The initial velocities were directly proportional to the enzyme concentrations between 0.06 and 0.30 units per 0.5 ml. The Lineweaver-Burk plot yielded positive allosteric behavior for the tetrameric enzyme. The K' and the Hill coefficient, n, calculated from Hill plot were found to be 4.7 mM and 1.26 (r = 1.00), respectively. These values are in good agreement with the literature.
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PMID:A new enzyme-coupled spectrophotometric method for the determination of arginase activity. 401 34

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.
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PMID:Activities of enzymes involved in amino-acid metabolism in developing rat placenta. 610 12

The activities of a number of enzymes in rat liver have been measured at different times during adulthood and senescence and expressed as a percentage of maximal activity that can be attained after hormonal stimulation. Three different profiles can be detected. Type I profile shows decreasing activities during adolescence (1--3 months of age), increasing activities during adulthood (4--12 months of age) and relatively high activities thereafter. Enzymes of this group are carbamoyl-phosphate synthase and arginase; DNA content shows the same pattern. Type II profile shows decreasing activities during adolescence and relatively low activities thereafter. Enzymes of this group are tyrosine aminotransferase, glucose-6-phosphatase, and glucokinase. Type III profile shows relatively high activities during adolescence, adulthood and senescence. Enzymes of this group are ornithine transcarbamoylase, glutamate dehydrogenase and hexokinase. Some enzymes are constant with age in females, but slowly decrease in activity with age in males; decreasing levels of androgens and possibly also thyroid hormones can explain this decrease in males. Decreasing activities of carbamoyl-phosphate synthase and arginase during adolescence can be attributed to a depressant effect of gonadal hormones. The difference between relatively high and relatively low basal activities of enzymes in adult and senescent rats corresponds with their relatively long and short half-lives, respectively. This relation implicates a similar rate of synthesis of glucocorticosteroid hormone-dependent enzymes.
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PMID:Changes in the control of enzyme clusters in the liver of adult and senescent rats. 611 95

Enzyme activities and DNA content have been measure in axolotl liver during the metamorphic period (4-8 months after spawning). Three different types of enzyme activity profiles were observed. In the type I profile (carbamoyl-phosphate synthase, arginase, ornithine transcarbamoylase, and glutamate dehydrogenase) enzyme activity is high in the youngest animals studied, and shows a minimum at 5 months followed by a maximum at 8 months of age. Thereafter activities do not change or slightly decrease. In the type II profile (tyrosine aminotransferase, glucose-6-phosphatase) enzyme activity shows a peak at 5 months of age and is low thereafter. Hexokinase, the enzyme with a type III profile, shows high activity throughout the metamorphic period. DNA content remains high throughout the metamorphic period but decreases 50% between 9 and 12 months of age, probably due to an increase in the size of the hepatocytes. No glucokinase activity was detected. High activities of cluster II enzymes represent early metamorphic events, while the rising part of cluster I is associated with late metamorphic events. The apparent molecular specific activity increases during natural development between 5 and 9 months of age, or precociously, upon thyroid hormone treatment. This change in apparent molecular specific activity is correlated to the advent of ureotelism.
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PMID:Enzyme clusters during the metamorphic period of Ambystoma mexicanum: role of thyroid hormone. 612 71

The amino-acid enzymes (aspartate-, alanine- and tyrosine transaminases, serine dehydratase, glutamate dehydrogenase, glutamine synthetase, adenylate deaminase and arginase) activities in the liver and kidney of developing rats (days 19 and 21 after conception and 1, 5, 10, 20 and 30 after birth) compared with adults were determined in crude homogenates. Most enzymes attained the adult levels early after birth or at weaning, showing a marked trend towards amino-acid nitrogen conservation during late foetal and specially during the neonatal period, increasing their activity during lactation. It is postulated that these changes are closely related to availability of low grade protein in diet as well as to maturation of amino-acid homeostasis maintenance for growth.
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PMID:Amino-acid enzyme activities in liver and kidney of developing rats. 618 14


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