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. The activities of citrate synthase and NAD+-linked and NADP+-linked isocitrate dehydrogenases were measured in nervous tissue from different animals in an attempt to provide more information about the citric acid cycle in this tissue. In higher animals the activities of citrate synthase are greater than the sum of activities of the isocitrate dehydrogenases, whereas they are similar in nervous tissues from the lower animals. This suggests that in higher animals the isocitrate dehydrogenase reaction is far-removed from equilibrium. If it is assumed that isocitrate dehydrogenase activities provide an indication of the maximum flux through the citric acid cycle, the maximum glycolytic capacity in nervous tissue is considerably greater than that of the cycle. This suggest that glycolysis can provide energy in excess of the aerobic capacity of the tissue. 2. The activities of glutamate dehydrogenase are high in most nervous tissues and the activities of aspartate aminotransferase are high in all nervous tissue investigated. However, the activities of alanine aminotransferase are low in all tissues except the ganglia of the waterbug and cockroach. In these insect tissues, anaerobic glycolysis may result in the formation of alanine rather than lactate.
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PMID:Activities of citrate synthase, NAD+-linked and NADP+-linked isocitrate dehydrogenases, glutamate dehydrogenase, aspartate aminotransferase and alanine aminotransferase in nervous tissues from vertebrates and invertebrates. 0 Oct 3

Seven healthy men volunteers received 6.6 +/- 1.3 (SD) percent-hours of halothane oxygen anesthesia without surgery. Serum bilirubin, alanine aminotransferase, and aspartate aminotransferase significantly increased after anesthesia, which may indicate subclinical liver-cell damage. Creatine kinase of skeletal muscle origin increased above 90 U/liter in six subjects, indicating subclinical muscle-cell damage. Cortisol, triiodothyronine uptake, thyroxine, and free thyroxine index increased significantly immediately after anesthesia. Serum bromide concentrations had increased by fivefold on the second day after anesthesia, and on the ninth day was still elevated fourfold. Oral temperatures increased 0.7 degrees C 6 h post-anesthesia, possibly because of increased thyroxine activity. Lactate dehydrogenase, hydroxybutyrate dehydrogenase and gamma-glutamyltransferase activities did not change significantly. No drugs administered during the course of this study chemically interfered with any of the test methods used.
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PMID:Effect of halothane anesthesia on muscle, liver, thyroid, and adrenal-function tests in man. 0 91

Gamma-glutamyl transpeptidase activity in kidney homogenates, aspartate and alanine aminotransferase activities in liver homogenates, and cholinesterase activity in brain homogenates were determined in nonpregnant and pregnant guinea pigs exposed to absorption through the skin of the epoxy resin triethylenetetramine. Elevated activity of gamma-glutamyl transpeptidase in the kidneys of pregnant animals, and aspartate aminotransferase in the liver of nonpregnant guinea pigs were observed.
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PMID:Influence of industrial toxic compounds on pregnancy. VI. Some tissue enzymes in pregnant guinea pigs exposed to the action of triethylenetetramine. 0 46

The cerebral metabolic effects of 2.5, 5, 7.5, 10, 20, 30 and 60 min exposure to 1% CO were studied in lightly anesthetized rats by measurement of cerebral cortical contents of selected glycolytic and citric acid cylce intermediates, as well as tissue energy phosphates. The initial change in the glycolytic sequence occurred at 2.5 min with decreases in tissue glucose and glucose-6-phosphate and increases in fructose-1-6-diphosphate which indicated an activation of phosphofructokinase and hexokinase. The "crossover" pattern between glucose-6-phosphate and fructose-1,6-diphosphate was present at 5, 7.5 and 10 min, but not at 20, 30 and 60 min and thus confirmed previous observations that detection of phosphofructokinase activation in acute unifactorial cerebral hypoxia requires tissue study during the early phases of the experimental exposure. The initial activation of phosphofructokinase occurred in the absence of detectable changes in the tissue content of ATP, ADP, AMP or phosphocreatine and therefore suggested that an imbalance of tissue energy homeostasis is not a prerequisite for the activation of glycolysis in CO intoxication. One percent CO resulted in an increasing malate/oxaloacetate ratio at 5 min, followed by a decrease in alpha-ketoglutarate and aspartate at 7.5 min which suggested a shift in the aspartate aminotransferase reaction towards the replenishment of oxaloacetate removed via the malate dehydrogenase reaction. Subsequent increases in alpha-ketoglutarate at 10, 20, 30 and 60 min were associated with increases in alanine, indicating a contributing role for a secondary shift of the alanine aminotransferase reaction in the replenishment of alpha-ketoglutarate. A comparison of the CO induced changes in the glycolytic and citric acid cycle pathways with those seen in acute hypoxemia indicates no basic qualitative differences in the metabolic responses of brain tissue to the two conditions.
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PMID:Cerebral carbohydrate metabolism during acute carbon monoxide intoxication. 1 62

The serum concentration of bilirubin and the activities of aspartate aminotransferase (ASAT, GOT), alanine aminotransferase (ALAT, GPT), gamma-glutamyltransferase (GT), total amylase and pancreatic isoamylase have been determined in serum of 182 male chronic alcoholics. Twelve per cent had abnormally high levels of bilirubin, 73% increased activity of S-ASAT, 50% increased S-ALAT, and 69% increased S-GT. The highest values were often found after 5-20 years of well documented alcoholism. Some patients with alcoholism of more than 20 years' duration displayed a slight tendency towards normalization of the activities. For all parameters the scatter around the mean was greater in the patients than in the controls. Patients who had had attacks of delirium showed slightly higher S-ASAT and S-ALAT than other alcoholics. Determination of S-ALAT and S-bilirubin did not add to the cases with abnormal laboratory tests demonstrated by the combination of S-ASAT and S-GT. In 14 patients the above mentioned parameters were within normal limits, even though severe alcoholism had lasted for many years. Isoamylase determination disclosed 20% to have decreased activity of pancreatic isoamylases in serum, whereas only 6% had low total serum amylase activity.
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PMID:Amylase, hepatic enzymes and bilirubin in serum of chronic alcoholics. 1 9

In previous studies it was found that: (a) aspartate aminotransferase increases the aspartate dehydrogenase activity of glutamate dehydrogenase; (b) the pyridoxamine-P form of this aminotransferase can form an enzyme-enzyme complex with glutamate dehydrogenase; and (c) the pyridoxamine-P form can be dehydrogenated to the pyridoxal-P form by glutamate dehydrogenase. It was therefore concluded (Fahien, L.A., and Smith, S.E. (1974) J. Biol. Chem 249, 2696-2703) that in the aspartate dehydrogenase reaction, aspartate converts the aminotransferase into the pyridoxamine-P form which is then dehydrogenated by glutamate dehydrogenase. The present results support this mechanism and essentially exclude the possibility that aspartate actually reacts with glutamate dehydrogenase and the aminotransferase is an allosteric activator. Indeed, it was found that aspartate is actually an activator of the reaction between glutamate dehydrogenase and the pyridoxamine-P form of the aminotransferase. Aspartate also markedly activated the alanine dehydrogenase reaction catalyzed by glutamate dehydrogenase plus alanine aminotransferase and the ornithine dehydrogenase reaction catalyzed by ornithine aminotransferase plus glutamate dehydrogenase. In these latter two reactions, there is no significant conversion of aspartate to oxalecetate and other compounds tested (including oxalacetate) would not substitute for aspartate. Thus aspartate is apparently bound to glutamate dehydrogenase and this increases the reactivity of this enzyme with the pyridoxamine-P form of aminotransferases. This could be of physiological importance because aspartate enables the aspartate and ornithine dehydrogenase reactions to be catalyzed almost as rapidly by complexes between glutamate dehydrogenase and the appropriate mitochondrial aminotransferase in the absence of alpha-ketoglutarate as they are in the presence of this substrate. Furthermore, in the presence of aspartate, alpha-ketoglutarate can have little or no affect on these reactions. Consequently, in the mitochondria of some organs these reactions could be catalyzed exclusively by enzyme-enzyme complexes even in the presence of alpha-ketoglutarate. Rat liver glutamate dehydrogenase is essentially as active as thebovine liver enzyme with aminotransferases. Since the rat liver enzyme does not polymerize, this unambiguously demonstrates that monomeric forms of glutamate dehydrogenase can react with aminotransferases.
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PMID:Effect of aspartate on complexes between glutamate dehydrogenase and various aminotransferases. 1 47

We report the intermediate-term effects of three consecutive evenings of moderate ethanol ingestion (0.75 g/kg body weight each evening) on activity values for alkaline phosphatase, gamma-glutamyltransferase, creatine kinase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in sera of nine apparently healthy young adults. We define "intermediate-term" effects as those occurring between 10 h and 100 h after completion of the ethanol consumption schedule. The most pronounced changes in enzyme activity for the group of volunteers were: gamma-glutamyltransferase, +25% at 60 h after ethanol ingestion; alanine aminotransferase, +12% at 60 h after ethanol; and aspartate aminotransferase,--12% at 60 h after ethanol. All three enzymes exhibited similar time courses, i.e., mean peak activity changes were observed at 60 h, and all three mean enzyme activity values returned to near baseline by 100 h. The possible explanations for the observed changes and the clinical significance are discussed.
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PMID:The effects of ethanol (0.75 g/kg body weight) on the activities of selected enzymes in sera of healthy young adults: 1. Intermediate-term effects. 1 40

Comparative biochemical studies on phosphorylase b, aspartate aminotransferase and alanine aminotransferase in muscles of various vertebrates (the lamprey Lampetra fluviatilis, dogfish Squalus acanthias, rays Dasyatis pastinaca and Raja clavata, teleosts Scorpaena porcus, Spicara smaris, Esox lucius, Tinca tinca, Abramis brama, Lucioperca lucioperca, Cyprinus carpio, Salmo ischchan, frog Rana temporaria, tortoise Testudo horsfieldi) revealed some peculiarties of their molecular evolution. It was shown that isoenzyme PH-II, which comprises in most on the investigated lower vertebrates the main bulk of phosphorylase b, disappears in evolution of the type. Isoenzyme PH-I which is found in fisches in small amounts, increases in evolution becoming the sole form of phosphorylase b in skeletal muscles of endothermic animals. Mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase were found in all the vertebrates studied. Cytoplasmic isoenzyme from ectothermic and endothermic animals does not differ significantly, whereas the mitochondrial one undergoes considerable changes in the evolution of vertebrates.
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PMID:[Molecular evolution of glycogen phosphorylase and aminotransferases of vertebrate muscle tissue]. 1 51

Details of a systematic approach to suitability testing of commercial control sera are given for substrate optimized L-aspartate aminotransferase and L-alanine aminotransferase methods at 37 degrees C. Their acceptability for control purposes of standardized methods depends on: (1) the range of control values in relation to borderline values, (2) stability, (3) aspect, clarity, (4) NADH consumption in preincubation time, (5) blank activities, (6) kinetic data as half saturation constants and saturation curves, (7) influence of effectors, (8) isoenzyme pattern. These evaluation criteria are proposed for suitability testing. The term "representativeness" should be introduced as a special criterion for main characteristics of control materials. The authors want to point out the close connection with standardization of methods.
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PMID:Suitability of commercial enzyme control sera for the quality control of activity determinations of L-aspartate aminotransferase and L-alanine aminotransferase in human serum. 1 83

Conditions for accurate measurement of catalytic activity of aspartate aminotransferase and alanine aminotransferase in human serum have been reinvestigated. The basic variables (kind of buffer, buffer concentration, pH, ion effects, and the influence of pyridoxal-5-phosphate) can now be considered optimized. On this basis, the kinetic parameters of both aminotransferases were determined, i.e., Michaelis and inhibitor constants for substrates and reaction products. With a mathematical approach for two-substrate enzyme reactions the substrate concentrations were calculated from the viewpoints "most economical," "most convenient," and "lowest variability." Also the conditions for the indicator reactions have been newly defined with respect to a kinetic model. All calculated data were rechecked experimentally and it can be shown that both approaches fully agree. Furthermore, we show that the mathematical approach allows more precise recommendations for optimized methods. For technical reasons, the catalytic activity of aspartate aminotransferase in human serum can only be measured as a 0.96 fraction of its theoretical maximum velocity, the catalytic activity of alanine aminotransferase as a 0.91 fraction. The assay conditions for a Reference Method are finally described and recommendations are made for optimized routine methods for determination of the catalytic activity of these transferases in human serum.
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PMID:Optimization of methods for aspartate aminotransferase and alanine aminotransferase. 2 9


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