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:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Factors regulating the release of alanine and glutamine in vivo were investigated in starved rats by removing the liver from the circulation and monitoring blood metabolite changes for 30 min. 2. Alanine and glutamine were the predominant amino acids released into the circulation in this preparation. 3. Dichloroacetate, an activator of pyruvate dehydrogenase, inhibited net alanine release: it also interfered with the metabolism of the branched-chain amino acids valine, leucine and isoleucine. 4. L-Cycloserine, an inhibitor of alanine aminotransferase, decreased alanine accumulation by 80% after functional hepatectomy, whereas methionine sulphoximine, an inhibitor of glutamine synthetase, decreased glutamine accumulation by the same amount. 5. It was concluded that: (a) the alanine aminotransferase and the glutamine synthetase pathways respectively were responsible for 80% of the alanine and glutamine released into the circulation by the extrasplanchnic tissues, and extrahepatic proteolysis could account for a maximum of 20%; (b) alanine formation by the peripheral tissues was dependent on availability of pyruvate and not of glutamate; (c) glutamate availability could influence glutamine formation subject, possibly, to renal control.
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PMID:Factors regulating amino acid release from extrasplanchnic tissues in the rat. Interactions of alanine and glutamine. 0 55

Biotin deficiency in Aspergillus nidulans resulted in a 70% increase of the protein content and increased levels of free and bound aspartate, glutamate, serine, leucine and methionine. Likewise, the activities of NADP+ glutamate dehydrogenase, NAD+ gluatmate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were significantly increased. The total RNA content increased while the DNA content was unaffected. The rRNA/tRNA ratio remained higher in biotin-deficient cells. Supplementation of glutamate, aspartate, serine, leucine and methionine to the culture medium raised the rRNA/tRNA ratio, and the difference observed in the qualitative and the quantitative patterns of protein and dry cell mass between normal and biotin-deficient cultures was abolished.
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PMID:Factors affecting protein synthesis during biotin deficiency in Aspergillus nidulans. 4 77

Chronic ammonia toxicity in experimental mice was induced by exposing them for 2 and 5 days to 5 % (v/v) ammonia solution. The enzymes concerned with glutamate metabolism (aspartate-, alanine- and tyrosine aminotransferases, glutamate dehydrogenase and glutamine synthetase) and (Na+ + K+)-ATPase were estimated in the three regions of brain (cerebellum, cerebral cortex and brain stem) and in liver. Glutamate, aspartate, alanine, glutamine and GABA, RNA and protein were also estimated in the three regions of brain and liver. A significant rise in the activity of (Na+ + K+)-ATPase in all the three regions of brain along with a fall in the activity of alanine aminotransferase was noticed. Changes in the activities of other enzymes were also observed. A significant increase in alanine and a decrease in glutamic acid was observed while no change was observed in the content of other amino acids belonging to the glutamate family. As a result of this, changes in the ratios of glutamate/glutamine and glutamate + aspartate/GABA was observed. The results indicated that the brain was in a state of more depression and less of excitation. Under these conditions the liver tissue was showing a profound rise in the activity of the enzymes of glutamate metabolism. The results are further discussed.
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PMID:Chronic metabolic effects of ammonia in mouse brain. 9 19

1. The activities of lysozyme, acid and alkaline phosphatases, beta-glucuronidase, amylase, lipase, glutamate-oxalacetate transaminase, and glutamate-pyruvate transaminase in the whole hemolymph and 4000 g pellets and supernatants of Mya arenaria were determined. 2. All of these enzymes, except for amylase, occurred in whole hemolymph as well as in the 4000 g pellet and supernatant. 3. Based on earlier observations, these enzymes are believed to be of cellular origin within hemolymph cells. 4. In the case of amylase, it only occurred in the whole hemolymph and/or serum and is believed to have originated from the crystalline style.
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PMID:Selected enzyme activities in Mya arenaria hemolymph. 9 92

Adaptation of Ehrlich ascites tumor cells to serial cultivation in media with progressively elevated (hypertonic) NaCl content ("high NaCl"-tolerant cells) has resulted in progressive increases of the cellular activities of NAD-dependent glycerol-3-phosphate dehydrogenase (EC 1.1.1.8), NAD-dependent malate dehydrogenase (EC 1.1.1.37), glutamate--oxalacetate transaminase (EC 2.6.1.1), NAD (P)-dependent glutamate dehydrogenase (EC 1.4.1.3), NADP-dependent isocitrate dehydrogenase (EC 1.1.1.42). The activities of glutamate-pyruvate transaminase (EC 2.6.1.2.) and of glycolytic enzymes as phospho-fructokinase (EC 2.7.1.11), glyceraldehydephosphate dehydrogenase (EC 1.2.1.12) and lactate dehydrogenase (EC 1.1.1.27) were only slightly and not in progressive manner (in response to the progressive increase of the environmental NaCl concentration) affected. These changes are discussed with respect to a metabolic pattern of these "high NaCl"-tolerant cells which is compatible with increased energy requirements, especially for active cation transport. It is suggested that these increased cellular enzyme activities reflect an increased transfer of reducing equivalents across mitochondrial membranes (via the "glycerophosphate cycle and the malate-aspartate shuttle") and possibly a stimulated lipid metabolism. These alterations in the level of enzyme activities must be regarded asan adaptive cellular response to the "high NaCl" environment, since readaptation to growth in regular isotonic media resulted in a reversion to the enzyme pattern characteristic of the parent cells.
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PMID:Changes in enzyme pattern of Ehrlich ascites tumor cells following serial cultivation in media with increased (hypertonic) NaCl content. 12 1

The blue-green alga Anacystis nidulans (strain L 1402-1) was grown at +37 degrees C in air (0.03 vol% CO2 and in air enriched with 3.0 vol% CO2. The effects of several inhibitors on the activity of aminotransferases, 14CO2 fixation and radioactive photosynthetic products of Anacystis were studied. No serine-pyruvate aminotransferase activity could be found in 10-2 M isonicotinyl hydrazide (INH); under the influence of this inhibitor aspartate and alanine aminotransferase were decreased about 49% respectively 17.6%. Serine-pyruvate and alanine aminotransferase activity decreased to more than 50% in 10-3 M glyoxalbisulfite. The obtained inhibitory effect of 10-4 M HPMS on serine-pyruvate aminotransferase (35%) was stronger than one the other aminotransferases. DCMU (5 x 10-6 M) inhibition on alanine aminotransferase activity was 83.7%. Under the influence of 10-3 M glyoxalbisulfite no 14C-labelled amino acids could be detected after 5 min photosynthesis; 14C-labelling of phosphoenolpyruvate, malate, phosphoglycolate and glycolic acid increased. Isonicotinyl hydrazide (10-2 M) caused in comparison to the control experiment a lower radioactivity in aspartate glutamate and phosphoenolpyruvate. The results are discussed with reference fo the operation of the glycolate pathway and a carboxylation reaction of phosphoenol-pyruvate in the blue-green alga Anacystis nidulans.
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PMID:[Activity of aminotransferases in the blue green alga Anacystis nidulans]. 13 84

1. A reversible transamination reaction between L-glutamate and pyruvate, or L-alanine and 2-oxoglutarate, takes place in the mitochondrial and cell sap fractions of rat brain. 2. The maximum rate of the transamination reaction in both subfractions was observed in the presence of a keto- substrate concentration of 2.5 mM only, but an amino- donor concentration of 20 mM. 3. The apparent Menten-Michaelis constants for pyruvate and 2-oxoglutarate were of a 10(-4) M and for L-glutamate and L-alanine of a 10(-3) M order and were approximately the same for both fractions. 4. The ratio of the initial rate of the L-alanine + 2-oxoglutarate to the L-glutamate + pyruvate transamination reaction in the cell sap and mitochondrial fractions amounted to up to 2. 5. The apparent equilibrium constant derived from the Haldane equation was 7.01 for cell sap alanine aminotransferase and 4 for the mitochondrial enzyme. 6. Increasing pyridoxal-5'-phosphate concentrations in the incubation medium were accompanied by only non-significant stimulation of alanine aminotransferase activity in the mitochondrial and cell sap fractions. 7. A comparison of the kinetic data obtained on mitochondrial and cell sap alanine aminotransferases in vitro with the actual substrate concentrations in the transamination reaction in nervous tissue in vivo indicates that the direction of the transamination reaction in situ seems to be determined simply by compartmentation and by dynamic changes in amino- and keto- substrates in the mitochondrial and cell sap spaces.
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PMID:Kinetics of the alanine aminotransferase reaction in the mitochondrial and cell sap fractions of rat brain. 14 Mar 99

Double isotope procedures (3H and 14C) were used in vivo to investigate a) slow long-term gluconeogenic actions of adrenal glucocorticoids, and b) rapid stimulation of gluconeogenesis by glucagon. [U-14C,6-3H]Glucose was administered to normal and adrenalectomized rats. No effect was observed on the [6-3H]glucose half-life suggesting the dicarboxylic acid shuttle is unaffected by adrenalectomy; the Cori cycle is also not influenced. Loads of [14C]aspartate, [14C]glutamate, or [14C]alanine were given to normal and adrenalectomized rats. Simultaneously, in vivo transaminase activity was studied by measuring the appearance of 3H2O in body water after administration of [2-3H]aspartate, [2-3H]glutamate, or [2-3H]alanine, Adrenalectomy has no influence on the incorporation of glutamate or aspartate into glucose or on their in vivo transaminases. Diminution of incorporation of [14C]alanine into glucose and alanine transaminase activities occurs only when rats are given unphysiological loads. These studies support the contention that glucocorticoid rate-limiting actions occur in extrahepatic tissues to produce an increased flow of glucose precursors to the liver. [U-14C,3-3H]Glucose was used to investigate the effect of glucagon on the hepatic fructose-6-phosphate (F-6-P) cycle. Glucagon administration resulted in a rapid drop in the 3H/14C ratio of circulating glucose, suggesting an increase in F-6-P recycling caused by activation of FDPase with little or no decrease in phosphofructokinase. Such a change would direct substrate flux toward gluconeogenesis.
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PMID:Use of 3H and 14C doubly labeled glucose and amino acids in the study of hormonal regulation of gluconeogenesis in rats. 19 46

Enzyme activity of lactate dehydrogenase, glutamate-oxalacetate and glutamate-pyruvate transaminase, creatine phosphokinase, cholinesterase, alkaline, acid and prostatic phosphatase and aldolase has been studied in a total of 213 subjects, of whom 97 were of good health, 63 had bone tumors and 53 suffered from osteomyelitis. The activities of the majority of the enzymes were found to become significantly changed in comparison with the norm. In both patient groups, the more striking differences being noted in that of osteomyelitis. However, enzymatic activity alone does not allow to differentiate the group of bone tumors from that of osteomyelitis, the differences between these two groups not being of significance in any one of the enzymes followed.
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PMID:Serum enzyme activity in bone tumors and osteomyelitis (LDH, GOT, GPT, CPK, CHE, ALP, AP, PP, ALD). 19 May 48

The sequential pattern of lipid accumulation and associated biochemical changes were studied in two commonly used experimental models of nutritional fatty liver in rats. Female rats were maintained for 8 weeks on high fat, low protein diets containing adequate methionine and choline, and drinking water ad libitum (Diet 1), or deficient in methionine and choline and containing 20% ethanol as a substitute for drinking water (Diet 2). Histologically, there was a progressive increase in liver lipids, mainly in the periportal areas. Occasional foci of liver cell necrosis with lipogranuloma formation occurred in areas of severe fatty change. These changes appeared earlier and were more marked in rats maintained on Diet 2. Electron micrographs revealed large lipid droplets in the liver cells, which sometimes contained myelin figures. The mitochondria were enlarged, distorted and appeared as amorphous structures with disorientated cristae in rats on Diet 1, whereas they had a condensed conformation in rats maintained on Diet 2. Rough endoplasmic reticulum was fragmented and degranulated particularly in rats on Diet 1, and smooth endoplasmic reticulum showed hyperplasia and vesiculation in rats on Diet 2. There was a progressive increase in the total liver lipids and triglycerides in both the groups of rats. This fatty change was accompanied by a significant increase in hepatic 3-hydroxybutyrate, acetoacetate, malate, 2-oxoglutarate, citrate, lactate, ammonia, glutamate, alanine and aspartate, and a significant decrease in oxaloacetate, urea and glucose concentrations. The mass action ratios for alanine aminotransferase, aspartate amino transferase, and glutamate dehydrogenase, generally moved in a parallel direction. Hepatic ATP content was considerably reduced accompanied by a decrease in [ATP]/[ADP] ratios and a significant increased in [lactate]/[pyruvate] and [3-hydroxybutyrate]/[acetoacetate] ratios. There was a corresponding decrease in the [NAD+]/[NADH] ratios both in the cytoplasmic and mitochondrial compartments. These biochemical changes were particularly severe in rats maintained on Diet 1 and Diet 2 for 8 weeks. There was a very good relationship between impaired mitochondrial and endoplasmic reticulum functions, redox and phosphorylation states, and the relevance of their changes to the fate of fatty liver cells.
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PMID:Lipid accumulation in the rat liver: a histological and biochemical study. 23


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