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:1.4.3.11 (glutamate dehydrogenase)
4,437 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The metabolism of glutamine and alanine in the lung was studied in rats made septic by a caecal ligation and puncture technique. 2. The blood glucose concentration was not significantly different in septic rats, but blood pyruvate, lactate, glutamine and alanine concentrations were markedly increased as compared with sham-operated rats. Conversely, blood ketone body and plasma cholesterol concentrations were significantly decreased in septic rats. Both plasma insulin and plasma glucagon concentrations were markedly elevated in response to sepsis. Sepsis resulted in a negative nitrogen balance. 3. Sepsis increased the rates of production of glutamine (52.5%, P less than 0.001), alanine (38.9%, P less than 0.001) and glutamate (48.6%, P less than 0.001) by lung slices incubated in vitro. 4. Sepsis increased lung blood flow by 27.6% (P less than 0.05). Blood flow and arteriovenous concentration difference measurement across the lung of septic rats showed an increase in the net exchange rates of glutamine (142.5%, P less than 0.001), alanine (129.4%, P less than 0.001), glutamate (100.9%, P less than 0.001) and ammonia (138.0%, P less than 0.001) as compared with sham-operated control rats. 5. Sepsis produced significant decreases in the lung concentrations of glutamine (36.8%), glutamate (20.8%), 2-oxoglutarate (64.8%) and AMP (18.3%). The lung concentrations of alanine (95.9%), ammonia (67.7%) and pyruvate (89.7%) were increased. 6. The maximal activities of glutamine synthetase (20.4%, P less than 0.05), phosphate-dependent glutaminase (18.9%, P less than 0.05) and alanine aminotransferase (25.5%, P less than 0.05) were increased, but there was no marked change in that of glutamate dehydrogenase, in the lungs of septic rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glutamine and alanine metabolism in lungs of septic rats. 168 36

Developmental dynamics was investigated in the activity of glutamate dehydrogenase (GDH, E.C. 1.4.1.2.-4) and glutamine synthetase (GS, E.C. 6.3.1.2) in different parts of the digestive tract of lambs, in dependence on the age from 10 to 90 days; the goal of these investigations was to elucidate in greater detail the role of the above enzymes in nitrogen metabolism. The activity of GDH, and of the coenzymes NADH and NADPH, was followed in the digesta because simple organisms (bacteria, fungi, plants) have two glutamate dehydrogenases: they differ from each other by coenzyme specificity, unlike GDH from animal sources which can utilize both NADH coenzyme and NADPH coenzyme (Fahien et al., 1965; Frieden, 1964). The following activities of GDH and GS were found out in trials with lambs at the age of 10, 20, 30, 40 and 90 days, as to the different parts of digestive tract: in the tissues of rumen, omasum, reticulum, spleen, duodenum, jejunum, ileum, int. caecum and colon the activity of GDH (NADH) varied from 0.031 to 0.305 nkat/mg dry matter, in the digesta from 0 to 2.92 nkat/mg dry matter. An investigation of GDH (NADH, NADPH) dynamics in the digesta of lambs showed the relatively high activity of GDH (NADH) in the digesta of colon at the age of 10 days and that of GDH (NADPH) in the digesta of int. caecum. The activity of GDH (NADH) was also found to be high in the digesta of int. caecum at the age of 20 days. In that period the activity of GDH (NADH, NADPH) in the digesta of rumen, omasum and reticulum was zero.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Glutamate dehydrogenase and glutamine synthetase activity in the digestive tract in lambs in relation to age]. 168 31

Two pathways serve for assimilation of ammonia in Paracoccus denitrificans. Glutamate dehydrogenase (NADP+) catalyzes the assimilation at a high NH4+ concentration. If nitrate serves as the nitrogen source, glutamate is synthesized by glutamate-ammonia ligase and glutamate synthase (NADPH). At a very low NH4+ concentration, all three enzymes are synthesized simultaneously. No direct relationship exists between glutamate dehydrogenase (NADP+) and glutamate-ammonia ligase in P. denitrificans, while the glutamate synthase (NADPH) activity changes in parallel with that of the latter enzyme. Ammonia does not influence the induction or repression of glutamate dehydrogenase (NADP+). The inner concentration of metabolites indicates a possible repression of glutamate dehydrogenase (NADP+) by the high concentration of glutamine or its metabolic products as in the case when NH4+ is formed by assimilative nitrate reduction. No direct effect of the intermediates of nitrate assimilation on the synthesis of glutamate dehydrogenase (NADP+) was observed.
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PMID:Assimilation of ammonia in Paracoccus denitrificans. 168 63

Changes in midgut gland, muscle, and gill tissue nitrogen metabolic profiles studied in a penaeid prawn, Metapenaeus monoceros, following its exposure to sublethal concentrations of phosphamidon, methyl parathion, DDT, and lindane. In all the pesticide-exposed prawn tissues, ammonia levels were significantly increased and a shift in the nitrogen metabolism toward the synthesis of urea and glutamine was observed. Inhibition of glutamate oxidation to ammonia and alpha-ketoglutarate by glutamate dehydrogenase suggest a mechanism whereby hyperammonemia is reduced by minimizing the addition of further ammonia to the existing elevated ammonia. Aspartate (AAT) and alanine (AlAT) aminotransferases demonstrated an increase in their activity levels, suggesting gluconeogenesis. Pesticide-induced stress also seems to induce ammoniagenesis, which is due to increased deamination of purines. Mechanisms to detoxify the ammonia by enhancing the synthesis of urea and glutamine were observed in the tissues.
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PMID:Effects of sublethal concentrations of phosphamidon, methyl parathion, DDT, and lindane on tissue nitrogen metabolism in the penaeid prawn, Metapenaeus monoceros (Fabricius). 169 Jan 8

The hyperthermophilic archaebacterium Pyrococcus furiosus contains high levels of NAD(P)-dependent glutamate dehydrogenase activity. The enzyme could be involved in the first step of nitrogen metabolism, catalyzing the conversion of 2-oxoglutarate and ammonia to glutamate. The enzyme, purified to homogeneity, is a hexamer of 290 kDa (subunit mass 48 kDa). Isoelectric-focusing analysis of the purified enzyme showed a pI of 4.5. The enzyme shows strict specificity for 2-oxoglutarate and L-glutamate but utilizes both NADH and NADPH as cofactors. The purified enzyme reveals an outstanding thermal stability (the half-life for thermal inactivation at 100 degrees C was 12 h), totally independent of enzyme concentration. P. furiosus glutamate dehydrogenase represents 20% of the total protein; this elevated concentration raises questions about the roles of this enzyme in the metabolism of P. furiosus.
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PMID:Extremely thermostable glutamate dehydrogenase from the hyperthermophilic archaebacterium Pyrococcus furiosus. 176 79

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 enzymes of the assimilation pathways in cultures of S. hygroscopicus grown in the presence of various nitrogen sources were investigated. No assimilation activity of glutamate dehydrogenase (GDH) was observed. Activities of alanine dehydrogenase (ADH), GDH, glutamine: 2-oxoglutarate aminotransferase (GOGAT) and glutamate synthetase (GS) were studied. High concentrations of ammonium and alanine induced ADH formation. The levels of GS remained low in media with NH4Cl. Various nitrogen sources had no impact on the activity of GOGAT which suggested the involvement of constitutive synthesis. ADH was likely to play an alternative role. Determination of the quantitative and qualitative composition of the free amino acids confirmed the involvement of the GS-GOGAT pathway in nitrogen assimilation. The concentration of ammonium ions in the media with one amino acid or in the presence of several amino acids lowered the antibiotic activity while in the media with alanine and the other nitrogen compounds it increased the antibiotic activity.
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PMID:[Impact of nitrogen assimilation on regulation of antibiotic production in Streptomyces hygroscopicus 155]. 187 81

The presence of peroxisomes and peroxisomal enzyme activities were investigated in the oleaginous yeast Apiotrichum curvatum ATCC 20509 (formerly Candida curvata D.) Catalase, a marker enzyme for peroxisomes, was measured in cell-free extracts prepared by sonication. The nature of the carbon and nitrogen sources in the growth medium greatly affected catalase activity. Cells grown on corn oil had high specific activity of catalase, but those grown on glucose, sucrose, or maltose had low specific activity. High specific activity of catalase was measured in cultures grown on media that supported poor growth (with soluble starch as carbon source or with methylamine, urea, or asparagine as nitrogen source). Peroxisomes from cells grown on corn oil were separated from other subcellular fractions in a discontinuous sucrose gradient. Major peaks of activity of fatty acid beta-oxidation and of two key enzymes in the glyoxylate cycle were found in fractions containing peroxisomes, but not in fractions corresponding to the mitochondria. Peroxisomal beta-oxidation showed equivalent activity with palmitoyl CoA or n-octanoyl CoA as substrate. Mitochondria did not seem to contain NAD-linked glutamate dehydrogenase. Peroxisomes with a homogeneous matrix and core surrounded by a single-layer membrane were observed with an electron microscope in cells grown on corn oil, but not in those grown on glucose. Staining with 3,3'-diaminobenzidine revealed that catalase activity was located in peroxisomes. Peroxisomes in this oleaginous yeast play important roles in lipid metabolism.
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PMID:Evidence of peroxisomes and peroxisomal enzyme activities in the oleaginous yeast Apiotrichum curvatum. 187 14

The present study utilized [15N]glutamine labeled at amide (5-N) and amino (2-N) groups to analyze the metabolic fate of glutamine nitrogen in basal and in acute pH regulation of ammoniagenesis. One-hour incubation of LLC-PK1 cultures in a media of pH 7.4, 7.0, or 7.6 containing either [5-15N]glutamine or [2-15N]glutamine resulted in parallel alterations in glutamine consumption in response to acute acid-base maneuvers. Incubation with [5-15N]glutamine resulted in substantial enrichment and production of ammonia at pH 7.4, which was unaffected by the changes in media pH, and in no significant enrichment of alanine, aspartate, and glutamate. In contrast, significant enrichment and production of 15N-labeled ammonia, alanine, aspartate, and glutamate were detected from cultures incubated with [2-15N]glutamine. Ammonia formation, from incubation with [2-15N]glutamine, was stimulated significantly by a low pH and inhibited by high pH. Alanine production was altered in a fashion similar to ammonia formation, whereas aspartate production was unaltered and glutamate formation significantly decreased by a low pH. Furthermore, a low pH significantly increased the production of alpha-ketoglutaramate in a fashion qualitatively similar to alanine production. In contrast to our prior conclusions based on total metabolite production, these studies indicate that although ammonia formation at pH 7.4 is predominantly generated from the mitochondrial phosphate-dependent glutaminase pathway, the increased ammonia formation in acute acidosis is a result of increased flux through glutamate dehydrogenase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pathways of acute pH regulation of ammoniagenesis in LLC-PK1 cells: study with [15N]glutamine. 188 9


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