Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.1 (aspartate aminotransferase)
 21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Energy metabolism in proliferating cultured rat thymocytes was compared with that of freshly prepared non-proliferating resting cells. Cultured rat thymocytes enter a proliferative cycle after stimulation by concanavalin A and Lymphocult T (interleukin-2), with maximal rates of DNA synthesis at 60 h. Compared with incubated resting thymocytes, glucose metabolism by incubated proliferating thymocytes was 53-fold increased; 90% of the amount of glucose utilized was converted into lactate, whereas resting cells metabolized only 56% to lactate. However, the latter oxidized 27% of glucose to CO2, as opposed to 1.1% by the proliferating cells. Activities of hexokinase, 6-phosphofructokinase, pyruvate kinase and aldolase in proliferating thymocytes were increased 12-, 17-, 30- and 24-fold respectively, whereas the rate of pyruvate oxidation was enhanced only 3-fold. The relatively low capacity of pyruvate degradation in proliferating thymocytes might be the reason for almost complete conversion of glucose into lactate by these cells. Glutamine utilization by rat thymocytes was 8-fold increased during proliferation. The major end products of glutamine metabolism are glutamate, aspartate, CO2 and ammonia. A complete recovery of glutamine carbon and nitrogen in the products was obtained. The amount of glutamate formed by phosphate-dependent glutaminase which entered the citric acid cycle was enhanced 5-fold in the proliferating cells: 76% was converted into 2-oxoglutarate by aspartate aminotransferase, present in high activity, and the remaining 24% by glutamate dehydrogenase. With resting cells the same percentages were obtained (75 and 25). Maximal activities of glutaminase, glutamate dehydrogenase and aspartate aminotransferase were increased 3-, 12- and 6-fold respectively in proliferating cells; 32% of the glutamate metabolized in the citric acid cycle was recovered in CO2 and 61% in aspartate. In resting cells this proportion was 41% and 59% and in mitogen-stimulated cells 39% and 65% respectively. Addition of glucose (4 mM) or malate (2 mM) strongly decreased the rates of glutamine utilization and glutamate conversion into 2-oxoglutarate by proliferating thymocytes and also affected the pathways of further glutamate metabolism. Addition of 2 mM-pyruvate did not alter the rate of glutamine utilization by proliferating thymocytes, but decreased the rate of metabolism beyond the stage of glutamate significantly. Formation of acetyl-CoA in the presence of pyruvate might explain the relatively enhanced oxidation of glutamate to CO2 (56%) by proliferating thymocytes.
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PMID:Glutamine and glucose metabolism during thymocyte proliferation. Pathways of glutamine and glutamate metabolism. 286 9

Red cell enzymes of three children with transient erythroblastopenia of childhood were measured and compared with those of age-matched normal children and children with hemolytic anemia. While the activity of "age-dependent" enzyme such as hexokinase, aldolase, glucose-6-phosphate dehydrogenase, glutamic-oxaloacetic transaminase, and pyruvate kinase were greatly increased in the red cells of children with hemolytic anemia, they were not decreased in the red cells of children with erythroblastopenia of childhood. Only the activity of pyrimidine 5'-nucleotidase was consistently low red cells of these children. These findings are inconsistent with the usual concept that red cell enzyme activities decline throughout red cell life span. Rather, they suggest that there may be very rapid loss in the activity of some red cell enzymes during the first few days of red cell life with little further decline in enzyme activity.
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PMID:Age-related red cell enzymes in children with transient erythroblastopenia of childhood and with hemolytic anemia. 298 25

The first 121 cases of upper urinary tract stone treated by extracorporeal shock wave lithotripsy (ESWL) at our clinic were analyzed. Three months after ESWL, 78% of the patients became stone free, and 17% of the patients had residual stone fragments which were less than 5 mm in diameter and considered passable. The success rate was therefore about 94.6%. No severe side effects were observed, although temporary elevations in serum creatinine phosphokinase, lactate dehydrogenase, glutamic-oxaloacetic transaminase, aldolase and total bilirubin occurred. These results indicated that ESWL was a safe and effective procedure for upper urinary tract stones.
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PMID:[Experience with extracorporeal shock-wave lithotripsy of upper urinary tract stones]. 337 6

The high degree of constancy of enzyme catalytic activity in the plasma of a given individual is regulated by a complex system of flux equilibria consisting of eight basic processes. Some of these processes are of primarily theoretic importance. Enzymes from all tissues of the body, including the liver, are released via a continuous physiological process into the interstitial space and get into the intravascular space by way of lymphatic transport. The release of enzymes from tissues directly into the intravascular space is of secondary importance as is the exchange of enzyme molecules across capillary membranes from the intravascular to the interstitial space and vice versa. In contrast, enzymes from circulating blood cells are transported directly into the intravascular space. Enzymes are removed from the intravascular space at rates which vary greatly between both enzymes and species. In a review of the literature, half-lives of diagnostically important enzymes in plasma of man, dogs and rats were given and the striking differences in the results for a given enzyme are discussed from a methodological point of view. In a mathematical analysis, data for lymphatic transport of enzymes from dogs and rats (Lindena et al. (1986) this J. 24, 19-33) and of enzyme efflux from in vivo ageing erythrocytes (Lindena et al. (1986) this J. 24, 49-59) into the plasma are related to the elimination rate constants of enzymes from the plasma. The contribution of lymphatically transported enzymes to the basal catalytic activity in plasma (Lindena & Trautschold (1986) this J. 24, 11-18) amounts to 55-80% for lactate dehydrogenase and malate dehydrogenase, 80-90% for adenylate kinase and phosphohexose isomerase, 90-95% for aspartate aminotransferase and aldolase and 99% for creatine kinase. A model of Ca2+ -mediated vesicular transport of enzymes out of ageing erythrocytes is proposed. The importance of lymphatically transported enzymes to total plasma catalytic activity in dogs and rats argues for a similar contribution of lymph transport in man.
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PMID:Kinetic of adjustment of enzyme catalytic concentrations in the extracellular space of the man, the dog and the rat. Approach to a quantitative diagnostic enzymology, V. Communication. 351 20

Excessive fat accumulation in the liver is a common metabolic disorder seen in humans and animals. Fatty liver was induced in the rat by feeding the animals with a sucrose rich diet containing 1% orotic acid for 2-3 weeks. In the sera from fatty liver rats there were significant changes in the level of alanine aminotransferase (+ 68.7%), malic dehydrogenase (+ 77.8%), gamma-glutamyl transpeptidase (- 53.4%) and total lipids (+ 26.6%). There were small to no changes in the levels of aspartate aminotransferase, glucose-6-phosphate dehydrogenase, lactic dehydrogenase, aldolase, malic enzyme, 6-phosphogluconic acid dehydrogenase, alkaline phosphatase and albumin. In fatty liver, significant differences were seen in the levels of glucose 6-phosphate dehydrogenase (+ 235%), malic enzyme (+ 170%), gamma-glutamyl transpeptidase (+ 113%), 6-phosphogluconate dehydrogenase (+ 63%), aspartate aminotransferase (+ 35.6%), malic dehydrogenase (+ 38%), lactic dehydrogenase (+ 37%), and alanine aminotransferase (- 23%). Comparison of the non-fatty part with the fatty part of the fatty liver showed larger changes in the non-fatty part of the liver, suggesting that during the fattening process, there is an induction of enzymes in the liver reaching a peak prior to lipid accumulation, declining thereafter during liver fattening. The increase in NADPH-generating lipogenic enzymes suggests that accumulated fat in the liver is at least partially from de-novo increased synthesis in the liver.
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PMID:Biochemical changes in liver and blood during liver fattening in rats. 377 7

Common bile duct ligation (CBDL) in rats was used to induce liver disease and secondary kidney damage. The biochemical changes in the liver, kidney and plasma were studied at 3, 6, 10 and 21 days post CBDL. The observed alterations climaxed at the 6th day following ligation. Renal, activities of aldolase (ALD), lactic dehydrogenase (LDH), isocitric dehydrogenase (ICDH), sorbitol dehydrogenase (SDH), and alkaline phosphatase (ALP), were lowered in CBDL rats. Further, microsomal Na,K-ATPase and Mg-ATPase and mitochondrial oxidative-phosphorylation were inhibited. In the liver from CBDL rats the activities of aspartate aminotransferase (AST), Mg-ATPase and ALP were elevated, while SDH, ALD, malic dehydrogenase (MDH), LDH, malic enzyme (ME) and Na,K-ATPase were lowered. Plasma enzymes, AST, ALP, MDH, LDH, ALD, acid phosphatase (ACP) and ICDH and the metabolites bile acids, bilirubin, creatinine and urea were elevated. Addition of bile acids or bilirubin at concentrations comparable to those found in the plasma of CBDL rats, to the reaction mixture of the various enzymes strongly inhibited most, particularly mitochondrial oxidative phosphorylation. High concentrations of these substances in the blood may explain the development of renal failure during liver disease and its reversibility when liver function returns to normal.
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PMID:Biochemical changes in liver, kidney and blood associated with common bile duct ligation. 378 11

It has been shown that prostaglandin E2 increases the activity of aspartate aminotransferase, alanine aminotransferase in the liver and striated muscle in parenteral feeding and increases the activity of aldolase in the liver but reduces it in the striated muscle. This demonstrates the enzymatic component in the mechanism of action of prostaglandin E2 on organ-tissue metabolism in parenteral feeding.
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PMID:[Effect of prostaglandin E2 on enzyme activity during parenteral feeding]. 392 96

In two families with severe sex-linked muscular dystrophy, high levels of alpha-hydroxybutyrate dehydrogenase (HBD), lactate dehydrogenase (LD), aspartate transaminase (AspT), aldolase, and creatine phosphokinase (CPK) were found in the sera of three young affected males. In both families the mother had a raised level of HBD activity. Four sisters of the three affected boys had raised serum enzyme levels, and they are regarded as presumptive carriers of the disease. Biopsy specimens of dystrophic muscle had LD and HBD contents which were significantly lower than those of control specimens, while the HBD/LD ratios were markedly greater. Muscle from two unaffected members of the same family also exhibited high ratios, indicating the presence of the electrophoretically fast LD isoenzymes, and this was confirmed by acrylamide-gel electrophoresis.
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PMID:Alpha-hydroxybutyrate dehydrogenase activity in sex-linked muscular dystrophy. 593 10

In myopathic disorders, abnormal serum enzyme activities are seen primarily in diseases of skeletal muscle where the condition involves the muscle fibers themselves. In denervation myopathies, serum enzyme activities are usually normal. The most dramatic increases of serum enzymes, particularly creatine kinase, are found in the dystrophic diseases, particularly Duchenne dystrophy. A review is given here of the many causes of abnormal serum enzyme activities where the source of enzymes is believed to be skeletal muscle. These include the dystrophies, various types of trauma, exercise, drug- and poison-induced causes including alcohol, malignant hyperthermia, inflammatory diseases, and miscellaneous causes. Tissue and serum activities are summarized for the commonly performed serum enzymes, i.e., CK, LD, AST, and aldolase. An extensive tabular and current description of the various types of dystrophies is given along with serum CK and pyruvate kinase activities.
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PMID:The enzymology of skeletal muscle disorders. 637 45

The effect of a four-week experiment on ten fa/fa Zucker rats (aged seven weeks at the beginning) fed on a lipid-rich diet (HL: 31 per cent w/w lipids, 45.6 per cent starch) was compared to that of a control diet (C: 10 per cent lipids, 66 per cent starch) on control Fa/- rats using a special pair-feeding apparatus that made it possible to obtain an identical intake rhythm. Energy level of the intake was significantly higher for the HL diet than for the C diet. At the end of the experiment, fa/fa rats remained obese and hyperlipemic, and still showed liver steatosis. With equal energy levels ingested, the obesity of fa/fa rats was comparable for both diets; hypertriglyceridemia and hypercholesterolemia were identical for both diets. When compared to the C diet, the HL diet modified neither their obesity nor their hyperlipemia. Obese rat liver on the HL diet showed lower levels for triacylglycerols, cholesterol, GGT, ALT, LDH and aldolase activities, while hepatic glycerol kinase and AST activities were higher than and comparable to, respectively, the C diet. Thus the HL diet led to a decreased liver steatosis for fa/fa rats as compared to the C diet.
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PMID:Influence of diet composition on obesity, hyperlipemia and liver steatosis in Zucker fa/fa rats pair-fed with Zucker Fa/- rats. 637 17


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