Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 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

Polarization of fluorescence measurements on aspartate aminotransferase (from pig heart cytosol) labeled with fluorescein isothiocyanate have been used to detect the formation of a soluble complex of this protein wich glutamate dehydrogenase from bovine liver. The binding of the labeled transaminase to dehydrogenase is detectable at catalytic concentrations of the enzymes.
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PMID:Fluorescence polarization studies on the binding between glutamate dehydrogenase and cytoplasmic aspartate aminotransferase. 0 87

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

1. Effects of chronic anticoagulant therapy in heart patients and anticonvulsant therapy in epileptics on gamma-glutamyl transpeptidase activity in serum were investigated. 2. The enzyme was elevated in 22% of 18 patients receiving anticoagulants. In these patients prothrombin time was also abnormally high. 3. 84% of 65 epileptics exhibited elevated gamma-glutamyl transpeptidase activity, 67% of which were not associated with elevated alkaline phosphatase or aspartate aminotransferase activities. In these latter cases, involvement of the liver was not apparent. 4. Possible relationships of anticonvulsant mediated enzyme induction or hepatic toxicity to elevated gamma-glutamyl transpeptidase activity in serum in epileptics is discussed.
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PMID:Activity of gamma-glutamyl transpeptidase in serum of patients receiving anticonvulsant of anticoagulant therapy. 0 35

Phosphypyridoxyl trifluoroethylamine has been synthesized as an active site-directed 19F NMR probe for aspartate transaminase. This coenzyme derivative adds stoichiometrically to the apotransaminase as observed by both fluorescence and circular dichroism measurements. The fluorinated phosphypyridoxamine derivative, when bound to the apotransaminase, will not dissociate upon extensive dialysis or passage through Sephadex G-25. The compound behaves as a pyridoxamine phosphate derivative and not as a coenzyme-substrate complex, since both competing anions and dicarboxylic acid inhibitors still bind to the phosphopyridoxyl trifluoroethylamine enzyme. The 19F NMR spectra of the enzyme-bound phosphopyridoxyl trifluoroethylamine were measured as a function of pH, ionic strength, and temperature. The 19F MNR of the enzyme-bound coenzyme derivative revealed no predetermined asymmetry in the subunits of aspartate transaminase insolution in terms of differences in chemical shift or resonance line shape between the two environments. A pH-dependent chemical shift change of the single 19F resonance was observed, which is consistent with the influence of a single ionization with an apparent pKa of 8.4 in 0.10 M KCl at 30 degrees. Increasing the ionic strength resulted in increasing values for the observed pKa, the highest recorded value was 9.1 in 3.0 M KCl. The temperature dependence of the pH titration of the chemical shift gives deltaH' of ionization of 10.5 kcal/mol. The evidence suggests a possible epsilon-amino group, electrostatically affected by positive charges, being responsible for the titration effect of the active site-bound fluorine derivative of pyridoxamine phosphate.
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PMID:Fluorine-19 as a covalent active site-directed magnetic resonance probe in aspartate transaminase. 0 32

The naturally occurring toxin L-2-amino-4-methoxy-trans-3-butenoic (AMB) acid irreversibly inhibits pyridoxal phosphate-linked aspartate aminotransferase. The inhibitor is a substrate for the enzyme, and as such is converted into a highly reactive intermediate which chemically reacts with an active site residue, thus irreversibly inactivating the enzyme. Enzymological and model studies on AMB are presented which enable one to determine the precise mechanism of action of this toxin. The mechanism involves Schiff base formation between the enzyme and toxin followed by alpha-C--H bond cleavage and aldimine isomerization to generate a bifunctional Michael acceptor. This molecule alkylates an active site residue by an addition and elimination route.
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PMID:Mechanism of the irreversible inhibition of aspartate aminotransferase by the bacterial toxin L-2-amino-4-methoxy-trans-3-butenoic acid. 0 51

Intraperitoneal administration to rats of D- or DL-alpha-hydrazinoimidazolylpropionic acid was found to produce a substantial inactivation of hepatic histidine ammonia-lyase (EC 4.3.1.3) in vivo. Proportional to this loss in enzyme activity was an impairment of the ability of treated rats to oxidize L-[ring-2-14C] histidine to 14CO2. Rats in which hepatic histidine ammonia-lyase activity was either depressed by DL-hydrazinoimidazolylproprionic acid injection or elevated by feeding a high protein diet displayed proportionately altered rates of 3H2O release into plasma water following L-[3-3H] histidine administration. Plasma L-histidine clearance following loading with this amino acid was similarly affected by these treatments. Administration of DL-alphal-hydrazinoimisazolylproprionic acid to rats was also found to inactivate non-specifically pyridoxal 5-phosphate enzymes in vivo; pyridoxine injection was found to reverse the DL-alpha-hydrazinoimidazolylproprionic acid-induced inactivation of hepatic aspartate aminotransferase (EC 2.6.1.1) in vivo, but not that of hepatic histidine ammonia-lyase. These findings demonstrate that histidine ammonia-lyase is the rate-limiting factor in L-histidine degradation in the rat. The potential usefulness of DL-hydrazinoimidazolylproprionic acid in the production of an animal model for histidinemia (hereditary histidine ammonia-lyase deficiency) is discussed.
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PMID:Studies on the production and assessment of experimental histidinemia in the rat. 0 33

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


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