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)

Activity levels of pyruvate dehydrogenase, enzymes of citric acid cycle, aspartate and alanine aminotransferases were estimated in mitochondria, synaptosomes and cytosol isolated from brains of normal rats and those injected with acute and subacute doses of ammonium acetate. In mitochondria isolated from animals treated with acute dose of ammonium acetate, there was an elevation in the activities of pyruvate, isocitrate and succinate dehydrogenases while the activities of malate dehydrogenase (malate----oxaloacetate), aspartate and alanine aminotransferases were suppressed. In subacute conditions a similar profile of change was noticed excepting that there was an elevation in the activity of alpha-ketoglutarate dehydrogenase in mitochondria. In the synaptosomes isolated from animals administered with acute dose of ammonium acetate, there was an increase in the activities of pyruvate, isocitrate, alpha-ketoglutarate and succinate dehydrogenases while the changes in the activities of malate dehydrogenase, aspartate and alanine amino transferases were suppressed. In the subacute toxicity similar changes were observed in this fraction except that the activity of malate dehydrogenase (oxaloacetate----malate) was enhanced. In the cytosol, pyruvate dehydrogenase and other enzymes of citric acid cycle except malate dehydrogenase were enhanced in both acute and subacute ammonia toxicity though their activities are lesser than that of mitochondria. In this fraction malate dehydrogenase (oxaloacetate----malate) was enhanced while activities of malate dehydrogenase (malate----oxaloacetate), aspartate and alanine aminotransferases were suppressed in both the conditions. Based on these results it is concluded that the decreased activities of malate dehydrogenase (malate----oxaloacetate) in mitochondria and of aspartate aminotransferase in mitochondria and cytosol may be responsible for the disruption of malate-aspartate shuttle in hyperammonemic state.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Activities of pyruvate dehydrogenase, enzymes of citric acid cycle, and aminotransferases in the subcellular fractions of cerebral cortex in normal and hyperammonemic rats. 272 22

The relationship between nitrogen assimilation, metabolism and aflatoxin formation has been investigated in a toxigenic and a non-toxigenic strain of Aspergillus parasiticus. Ammonia from the medium is mainly assimilated via NADP-requiring glutamate dehydrogenase. During growth NAD-requiring glutamate dehydrogenase followed an inverse pattern of activity with respect to NADP glutamate dehydrogenase. Alpha-ketoglutarate, the product of NAD glutamate dehydrogenase, stimulated acetate incorporation into aflatoxins. Glutamine synthetase, ornithine transcarbamylase, both utilizing glutamate as substrate were assayed under different growth conditions. An important regulatory role for glutamine synthetase is suggested. The metabolic route of asparagine utilization was also investigated. Both the known pathways, glutamate oxaloacetate transaminase and glutamate pyruvate transaminase are operative simultaneously.
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PMID:Nitrogen metabolism in Aspergillus parasiticus NRRL 3240 and A. flavus NRRL 3537 in relation to aflatoxin production. 287 96

Activity of enzymes participating in metabolism of glutamate and content of nicotinamide nucleotides was studied in rat liver tissue within 24 hrs after intramuscular administration of alpha-tocopheryl acetate at doses of 30 mg and 300 mg per kg of body mass. Excess of the vitamin was responsible for a decrease in the ratio NAD+/NADH in cytosol, for stimulation of glutamate dehydrogenase reaction, for a decrease of aspartate aminotransferase activity in mitochondria and of alanine aminotransferase activity in cytosol as well as for an increase of NADPH content.
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PMID:[Effect of alpha-tocopherol on glutamic acid metabolism and nicotinamide coenzyme levels in hepatocytes]. 287 84

We studied intestinal absorption of vitamin E in 26 adults with primary biliary cirrhosis (PBC) and 6 control subjects. Seven (27%) PBC patients were vitamin E-deficient based on the ratio of serum vitamin E to serum total lipid concentrations. An oral vitamin E tolerance test was performed in all patients and control subjects using a loading dose of 2000 IU alpha-tocopheryl acetate with measurement of serial serum vitamin E concentrations over 24 h. Vitamin E absorption was expressed as the maximal rise in serum vitamin E above baseline, the area under the oral tolerance test curve, and these two values divided by the fasting total serum lipid concentration. Absorption of vitamin E was significantly impaired in all PBC patients vs. control subjects (p less than 0.01), in vitamin E-deficient vs. vitamin E-sufficient PBC patients (p less than 0.05 to p less than 0.01), and in PBC patients with serum vitamin E levels below 10 micrograms/ml vs. those with serum vitamin E levels above 10 micrograms/ml (p less than 0.01). Vitamin E absorption was inversely related to stage of PBC, serum cholylglycine, total bilirubin, cholesterol, alkaline phosphatase, aspartate aminotransferase, and prothrombin time. Patients with serum vitamin E below 10 micrograms/ml, serum total bilirubin above 3 mg/dl, serum cholylglycine above 600 micrograms/dl, or serum alkaline phosphatase above 1000 IU/L had severe malabsorption of vitamin E and would be at high risk for the development of vitamin E deficiency. Therefore, vitamin E supplementation should be considered not only in patients in whom overt vitamin E deficiency is present, but also in PBC patients meeting these criteria.
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PMID:Intestinal malabsorption of vitamin E in primary biliary cirrhosis. 291 Jul 63

As part of a series of epidemiological and ecological studies of leishmaniasis in Jordan, we have made functional studies of four isolates from human lesions and from ear lesions of three field-collected Psammomys obesus. Primary isolates were subcultured, frozen stabilates prepared and BALB/c mouse infectivity experiments initiated. Each mouse was inoculated with 4-8 x 10(4) promastigotes into a hind footpad. Quantitative evaluation of the footpads showed enlargement three to four weeks postinoculation. Amastigotes were readily identified in smears from footpad lesions and promastigotes in culture. At 47 days, liver and spleen samples grew out promastigotes. Biochemical characterization of these seven isolates was made by isozyme analysis using cellulose acetate membrane electrophoresis of fructokinase, phosphoglucose isomerase, phosphoglucomutase, aspartate aminotransferase, malate dehydrogenase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Reference isolates used for comparison were Leishmania major, L. tropica minor, L. donovani, L. aethiopica and L. m. mexicana. All seven Jordan isolates showed enzyme electromorphs identical to L. major, confirming our ecological/epidemiological studies that P. obesus is a major reservoir for human cutaneous leishmaniasis in Jordan.
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PMID:Cutaneous leishmaniasis in Jordan: biochemical identification of human and Psammomys obesus isolates as Leishmania major. 304 29

Six Leishmania isolates from 3 indigenous Kenyans (2 isolates from one patient) and 2 Canadian visitors in Kenya were characterized by cellulose acetate electrophoresis. The isolates were compared among themselves and with reference strains of Leishmania donovani, L. aethiopica, L. major, L. tropica, and L. arabica using 9 enzymes: malate dehydrogenase (MDH), malic enzyme (ME), phosphogluconate dehydrogenase (6PGD), glucose-6-phosphate dehydrogenase (G6PD), aspartate aminotransferase (ASAT), adenylate kinase (AK), mannose phosphate isomerase (MPI), glucose phosphate isomerase (GPI), and phosphoglucomutase (PGM). Enzyme migration patterns of isolates from the 3 indigenous Kenyans were indistinguishable from those of 2 L. tropica reference strains. The isolates from the 2 Canadians yielded migration patterns of 7 enzymes that were indistinguishable from those of 2 L. tropica reference strains. However, migration patterns of 2 enzymes, PGM and ME, differed from all migration patterns of the 10 reference strains. Balb/c mice were inoculated with stationary phase promastigotes cultured from 3 stabilates from the lesions of 2 of the Kenyan patients. The mice developed no gross pathological lesions in 6 months time. All of the study patients developed cutaneous leishmaniasis while living in or visiting districts in Central and Rift Valley Provinces, Kenya. This is the first report of human cutaneous leishmaniasis caused by L. tropica indigenous to Africa south of the Sahara.
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PMID:Indigenous human cutaneous leishmaniasis caused by Leishmania tropica in Kenya. 317 40

727 consecutive drunken drivers were studied for laboratory markers of excessive alcohol consumption. Serum gamma-glutamyltransferase and alanine aminotransferase showed no differences and aspartate aminotransferase and blood alcohol concentration only small differences between groups of first and repeating drunk driving offenders. The best laboratory test to differentiate the repeating offenders with probably more serious alcohol problems from the first offenders was in our material serum acetate, the mean serum acetate level of the repeating offenders being highly significantly (P less than 0.001) higher than that of the first offenders or nonalcoholic controls. Serum acetate also differentiated first offenders from nonalcoholic controls (P less than 0.001). Our results suggest that serum acetate could be used for the screening of problem drinking among drunken drivers.
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PMID:Increased serum acetate as a marker of problem drinking among drunken drivers. 339 Feb 36

A new purification method has been developed which only exploits the chromatographic behaviour of avian liver mitochondrial aspartate aminotransferase enzymes (m-AAT), and permits a rapid isolation of the protein (4 days) in large quantities with high yield and low cost. m-AAT from turkey, chicken and quail livers have been isolated by chromatography on CM-Sepharose, Sephadex G-100 and 5' AMP-Sepharose using TEA-acetate buffer (pH 7.4), and specific activities (A.E.) of 311.6, 318.9, 320.1 I.U./mg respectively were obtained. Preparations were homogeneous as judged by various electrophoretic techniques and by size exclusion HPLC. The amino acid composition, Stokes Radius, subunit molecular weight and pI values have been determined and compared, finding no appreciable differences among them. In contrast, the absorption spectrum of the turkey enzyme differed from those of chicken and quail at both pH 7.4 and pH 5.0.
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PMID:Purification and comparative studies of several mitochondrial aspartate aminotransferases from avian liver. 343 3

The proposed system of continuous monitoring of enzyme activities is based primarily on the electrochemical behaviour of thiol compounds, and the experimental equipment is extremely simple. The determination of cholinesterase (EC 3.1.1.8) activity is described. The normal values obtained for men (73.9, s +/- 10.3 microkat/l) and for women (71.1, s +/- 10.2 microkat/l), lie within the usual range of analogous photometric methods. Systems for determination of the activities of alkaline phosphatase (EC 3.1.3.1) and adenosylhomocysteinase (EC 3.3.1.1) are described. The activity of aspartate aminotransferase (EC 2.6.1.1) is determined by a combination of enzyme reactions, in which CoA is released from acetyl-CoA. Analogous procedures are discussed for determinations of alanine aminotransferase (EC 2.6.1.2), lactate dehydrogenase (EC 1.1.1.27), lipase (EC 3.1.1.2), and phospholipase A2 (EC 3.1.1.4) activities, and for determination of substrates, e.g., acetate and carnitine. Possible determinations of an additional 199 enzyme activities and of some of substrates are suggested. By determining electrochemically active groups other than thiols this method becomes almost universally applicable.
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PMID:New system of continuous monitoring of enzyme activities and determination of some substrates. 344 Aug 58

Since ethanol consumption decreases hepatic aminotransferase activities in vivo, mechanisms of ethanol-mediated transaminase inhibition were explored in vitro using mitochondria-depleted rat liver homogenates. When homogenates were incubated at 37 degrees with 50 mM ethanol for 1 hr, alanine aminotransferase decreased by 20%, while aspartate aminotransferase was unchanged. After 2 hr, aspartate aminotransferase decreased by 20% and by 3 hr, alanine and aspartate aminotransferases were decreased by 31 and 23%, respectively. Levels of acetaldehyde generated during ethanol oxidation were 525 +/- 47 microM at 1 hr, 855 +/- 14 microM at 2 hr, and 1293 +/- 140 microM at 3 hr. Although inhibition of alcohol oxidation with methylpyrazole or cyanide markedly decreased ethanol-mediated transaminase inhibition, neither incubation with acetate nor generation of reducing equivalents by oxidation of lactate, malate, xylitol, or sorbitol altered the activity of either enzyme. However, semicarbazide, an aldehyde scavenger, prevented inhibition of both aminotransferases by ethanol. Moreover, incubation with 5 mM acetaldehyde for 1 hr inhibited alanine and aspartate aminotransferases by 36 and 26%, respectively. Cyanamide, an aldehyde dehydrogenase inhibitor, had little effect on ethanol-mediated transaminase inhibition. Thus, metabolism of ethanol by rat liver homogenates produces transaminase inhibition similar to that described in vivo and this effect requires acetaldehyde generation but not acetaldehyde oxidation. Since addition of pyridoxal 5'-phosphate to assay mixes did not reverse ethanol effects, aminotransferase inhibition does not result from displacement of vitamin B6 coenzymes.
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PMID:Evidence for the generation of transaminase inhibitor(s) during ethanol metabolism by rat liver homogenates: a potential mechanism for alcohol toxicity. 366 1


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