Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Cell-free extracts of rat brain catalyze the reactions of the purine nucleotide cycle. Ammonia is formed during the deamination but not the amination phase of the cycle. The activity of adenylate deaminase in brain is sufficient to account for the maximum rates of ammonia production that have been reported. The activity of glutamate dehydrogenase is not sufficient to account for these rates of ammonia production. The activities of adenylosuccinate synthetase and adenylosuccinase are nearly sufficient to account for the steady state rates of ammonia production observed in brain. Demonstration of the cycle in extracts of brain is complicated by the occurrence of side reactions, in particular those catalyzed by phosphomonoesterase, nucleoside phosphorylase, and guanase.
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PMID:Purine nucleotide cycle. Evidence for the occurrence of the cycle in brain. 0 96

The use of L-glutamate dehydrogenase (GLUD) as a reagent in staining mixtures to detect the isozymes of enzymes which catalyze the production of ammonia has been investigated. Methods have been devised for the electrophoresis and detection, using GLUD, of seven enzymes: cytidine deaminase, adenosine deaminase, adenosine monophosphate deaminase, arginase, argininosuccinase, D-amino acid oxidase, and D-aspartate oxidase. GLUD-linked staining methods appear to be sensitive, specific, and of general application.
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PMID:Detection after electrophoresis of enzymes involved in ammonia metabolism using L-glutamate dehydrogenase as a linking enzyme. 2 58

The widely used activity expressions for enzyme levels in tissues are discussed: microkatals per unit of tissue weight, protein weight, and DNA weight. The expression of microkatals present in a definite organ in reference to a standard animal weight, 100 g in the case of rat, is also used. The different expressions are applied to aspartate transaminase, glutamate dehydrogenase and AMP deaminase activities in liver, hind leg striated muscle and kidneys in rat. The conclusion is reached that measurements of enzyme activity in tissues should be expressed in more than one form, as the information drawn from one could differ substantially from that obtained from other, giving artifactual views of the metabolic role played by the enzyme in a given tissue.
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PMID:Different expressions for enzyme activities in organs of rat. Application to aspartate transaminase, glutamate dehydrogenase and AMP-deaminase. 72 35

Urea cycle enzymes are all shown to be active in dolphin liver. Acetylglutamate-independent cytoplasmic carbamylphosphate synthase is also present. Arginase is a basic protein, although less markedly basic than the dog enzyme. It is 118 per cent activated by heating at 50 degrees. Optimum pH is 10.5. Co++ and Ni++ inhibit the enzyme. AMP deaminase, glutamicoxaloacetic transaminase, glutamate dehydrogenase and ornithine transaminase are also active in dolphin liver.
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PMID:Urea cycle enzymes in the liver of a dolphin Platanista indi. 95 55

Pregnant rats of 19th and 21st days were given an acute nitrogen overload produced by an infusion of either 0.2 M ammonium acetate or 0.2 M glutamine. Metabolic adaptations to nitrogen excess were studied measuring--in fetomaternal unit--non-protein nitrogen content and the activities of enzymes related with ammonia metabolism. Maternal and fetal plasma urea levels were increased by ammonium acetate treatment. Glutamine overload increased more the amino acid content in the mothers than in conceptus. As response to ammonium acetate treatment, glutamate dehydrogenase activity in liver was more sensitive in pregnant than in nonpregnant rats, suggesting more nitrogen incorporation into amino acids in pregnancy. Regarding glutamine synthetase activity, both treatments had an opposite effect except in kidney. The adenylate deaminase activity of pregnant rats was inhibited similarly to nonpregnant rats by nitrogen overloads, but stronger after glutamine infusion. Placenta and fetal metabolism were adjusted, as the dams, to lack of ammonia production by nitrogen overloads and to glutamine synthesis by ammonium acetate infusion.
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PMID:Metabolic adaptations to nitrogen excess in late gestation in rat. 177 94

The present study deals with the effect of atrazine on nitrogen metabolism in the liver and brain of fish. Significant changes were seen in the levels of proteins, free amino acids, ammonia, urea, glutamine and the activity levels of proteases, glucogenic aminotransferases, branched-chain aminotransferases, glutamate dehydrogenase, glutaminase, arginase, AMP deaminase and adenosine deaminase in both the tissues of fish exposed to sublethal concentration of atrazine. The study reflects a shift in nitrogen concentration of atrazine. The study reflects a shift in nitrogen metabolism in the tissues of fish for efficient mobilization of end products of protein catabolism as a consequence of atrazine.
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PMID:Modulations in nitrogen metabolism in the hepatic and neuronal tissues of fish, Tilapia mossambica exposed to atrazine. 185 31

The activities of alanine-, aspartate- and branched-chain amino-acid transaminases, glutamine synthetase, glutamate dehydrogenase and adenylate deaminase in white adipose tissue of adult male rats have been determined in animals submitted to 12-h cold exposure (4 degrees C) or to 24-h food deprivation. Starvation resulted in small changes in glutamate dehydrogenase and alanine transaminase when expressed per unit of protein weight, inducing an increase in branched-chain amino-acid transaminase and glutamine synthetase. Cold exposure showed the same effects as starvation with respect to glutamate dehydrogenase and alanine transaminase, but induced increases in glutamine synthetase and aspartate transaminase. It is concluded that starvation increases the handling of some amino acids by white adipose tissue and the detoxification of the ammonia thus evolved. The changes observed suggest a different pattern of amino-acid metabolism enzyme changes with either cold or starvation.
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PMID:Amino-acid metabolism enzyme activities in rat white adipose tissue. 243 May 32

To contribute to our understanding of nitrogen metabolism in the developing chick we have studied in liver, intestine and yolk sac membrane the ontogeny of both aspartate- and alanine transaminases, glutamate dehydrogenase, adenylate deaminase, glutamine synthetase and xanthine dehydrogenase activities. Liver enzyme activities were much higher than those of the same enzymes in intestine and yolk sac membrane, the latter having the lowest activities. In the liver, both alanine transaminase and glutamate dehydrogenase increased their activity just before hatching, xanthine dehydrogenase and glutamine synthetase develop their highest activity just after hatching, while aspartate transaminase and adenylate deaminase attained the highest levels just with adulthood. From the pattern of enzyme activity in yolk sac membrane and intestine it can be inferred that after hatching, the amino-acid metabolism in these tissues is considerably enhanced, with higher production of ammonia from amino acids, as indicated by the rise in adenylate deaminase, as well as increased potentiality in production of both alanine and glutamine. It can be concluded that hatching coincides with a deep change of pace in amino-acid metabolism in the organs studied fully comparable with that observed in Mammals at the end of lactation, with the difference that the adaptation to the new diet in the case of the chick is much more sudden than weaning is for the rat.
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PMID:Amino-acid metabolism enzyme activities in the liver, intestine and yolk sac membrane of developing domestic fowl. 243 52

The infusion of ether anesthaetized rats with 0.2 M (1 mmols in total) ammonium acetate or glutamine were compared with the infusion of 0.2 M NaCl. The levels of circulating glucose, amino acids, lactate, urea and ammonium were measured as well as liver glycogen and tissue amino acids and the liver and muscle activities of carbamoyl phosphate synthetases I and II, glutamate dehydrogenase, glutamine synthetase and adenylate deaminase. Neither treatment altered the glucose and glycogen homeostasis. The infusion of ammonium did not result in increases in circulating ammonium, but resulted in increased circulating urea after a short delay; the infusion of glutamine resulted also in urea production but much later on. Glutamine infusion also resulted in increased tissue free amino-acid levels. There was little alteration in enzyme activities, except for decreased glutamine synthetase and adenylate deaminase activity in muscle of glutamine-infused rats and higher tissue carbamoyl phosphate synthetase II. The results agree with a fast removal of infused ammonium, and maintenance of glutamine, with their channeling towards urea production at a rate comparable with that of infusion, that did not alter significantly the homeostasis of the experimental animals.
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PMID:Glutamine and ammonium handling by anaesthetized rats. 247 81

Effects of stretching on muscle amino acids were tested in unloaded soleus by casting the foot in dorsiflexion on one limb of tail-casted, hindquarter-suspended rats. For comparison with unloading, amino acids also were measured in shortened extensor digitorum longus (EDL) in the same casted limb and in denervated leg muscles. Concentrations of tyrosine and glutamate were lower, while aspartate, ammonia, and the ratio of glutamine to glutamate were greater in the stretched than in the freely moving, unloaded soleus, but stretched did not differ from weight-bearing, control muscle. Therefore, stretching the soleus muscle prevented changes in certain amino acids due to unloading. Aspartate, ammonia, glutamine, and the ratio of glutamine to glutamate were lower in the shortened EDL than in the freely moving muscle of the contralateral limb, or in the control muscle. When denervated, these leg muscles also showed lower aspartate, ammonia, and ratio of glutamine to glutamate relative to innervated muscles. Since muscle shortening or denervation produced amino acid changes that mimicked the effects of unloading on the soleus, these responses must reflect the effect of muscle disuse. These data suggested that lower ammonia might cause the lower ratio of glutamine to glutamate with disuse. Because the fresh muscle energy charge, one factor which controls AMP deaminase, generally was not affected by disuse, altered deamination of glutamate via glutamate dehydrogenase may explain the variations in muscle ammonia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of stretching and disuse on amino acids in muscles of rat hind limbs. 256 86


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