Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Kochia scoparia (L.) Schrad. is a prospective forage crop for arid areas, although its potential value is constrained by occasional toxicity that may involve alteration of metabolic hormones. The present research compared serum clinical profiles and metabolic hormone concentrations in steers and wethers fed kochia hay (85% OM, 13% CP, 45% ADF, and 6.3% total oxalate) to those of suitable controls that were pair-fed equal amounts of DM as alfalfa hay (91% OM, 13% CP and 42% ADF). Eight steers (240 +/- 2 kg BW) that were pair-fed kochia or alfalfa hay for 21 d had similar levels of serum insulin (INS) or somatotropin (GH), but kochia lowered prolactin (PRL) (6.0 vs 118 ng/ml; P = .14). Kochia hay did not elevate serum bilirubin at d 21 in these steers; however, lactic dehydrogenase and aspartate aminotransferase activities were elevated 1.3-fold (P less than .05). Ten fine-wool wethers (29 +/- kg BW) pair-fed kochia or alfalfa hay for 21 d had similar levels of PRL and INS at d 0, 5, 10, and 21; however, GH was lower in wethers fed kochia at d 5 (P less than .05) and somewhat lower at d 10 and 21. Kochia elevated serum unconjugated bilirubin 1.25-fold over pair-fed controls (P = .06) and increased (P less than .05) activities of aspartate and alanine aminotransferases. Metabolic hormone responses to kochia hay differed in steers vs wethers during undemutrition and mild toxicosis that occurred within 3 wk.
 ...
PMID:Serum constituents and metabolic hormones in sheep and cattle fed Kochia scoparia hay. 188 3

Effects of an 18 min exercise test, on three separate occasions during a one year jump-training programme, was studied in seven horses. Determinations were carried out on venous blood for packed cell volume, haemoglobin, total protein, lactate and pyruvate, glucose, free fatty acids, insulin, glucagon, blood gases, bicarbonate, pH, aldolase, aspartate aminotransferase and alanine amino-transferase. Exercise caused a slight increase in lactate and pyruvate, total protein, aldolase, alanine aminotransferase, pO2, bicarbonate and pH. Glucose, free fatty acids and pCO2 levels decreased. Training caused no significant difference in these changes. However, during the year, increases in lactate and decreases in pH (resting levels) were observed.
 ...
PMID:Changes in some haematological and metabolic indices in young horses during the first year of jump-training. 191 34

A tiletamine hydrochloride/zolazepam hydrochloride combination was used successfully to immobilize captive untamed wild dogs (Lycaon pictus) (n = 16) at dosage rates ranging from 2.3 to 32.3 mg/kg. Animals remained immobilized for periods ranging from 35 min to 24 hr 14 min. There was a significant positive correlation (r = 0.85, P less than 0.01) between dosage rate and the time immobilized. Profuse salivation and intermittent mild myoclonal contractions were observed in some wild dogs. Mildly reduced partial oxygen and carbon dioxide pressures as well as reduced concentrations of bicarbonate were observed in arterial blood at 10 and 20 min after administration of the drug. Serum concentrations of sodium, potassium, chloride, phosphorus, calcium, magnesium, urea, creatinine, glucose, proteins, albumin, gammaglutamyltransferase, creatinine kinase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, insulin, cortisol and thyroxine are presented. These concentrations were found to be in agreement with values previously reported for wild dogs.
 ...
PMID:Immobilization of wild dogs (Lycaon pictus) with a tiletamine hydrochloride/zolazepam hydrochloride combination and subsequent evaluation of selected blood chemistry parameters. 206 44

Activities of alanine and aspartate aminotransferase in different muscle types and in the liver of streptozotocin diabetic rats were studied 1,2 and 3 days after administering of streptozotocin. It was shown that the activity of both enzymes was elevated in the "white" layer of the vastus lateralis, in the liver and in the heart, whereas it remained unchanged in the "red" layer of the same muscle, in the soleus and the diaphragm. It is concluded that the effect of acute insulin deficiency on the aminotransferase activity in skeletal muscles depends on the muscle fiber composition and does not appear in muscles with a high oxidative potential. These results indicate that muscle fiber composition should be taken into account when evaluating the role of insulin in amino acid metabolism in the muscle.
 ...
PMID:Alanine and aspartate aminotransferase activities in muscles of diabetic rats. 213 88

In rats, a moderately hepatotoxic single dose of diethylnitrosamine (DEN) 100 mg/kg causing depletion of liver glycogen, elevation of aspartate aminotransferase and decreased liver uptake of 3-O-methylglucose, resulted in substantial changes in insulin and glucagon balance. Two days after DEN, insulin binding to liver membranes and insulin removal by the liver were sharply reduced whereas its binding to muscle and adipocyte membranes remained unaltered. Serum insulin (random and after an overnight fast) remained normal. Intravenous (I.V.) insulin (10 U/kg) caused the usual degree of hypoglycemia that, however, lasted longer than in the control animals. Removal of glucagon by liver was also depressed in spite of its normal binding to hepatocytes, and peripheral serum glucagon was increased three-fold. I.V. glucagon (40 micrograms/kg) resulted in a blunted response of plasma glucose. I.V. glucose tolerance test (1 g/kg) remained normal in spite of the insulin increase to a level twice as high as in the controls, and in spite of nonsuppressed glucagon. These changes were still present after 1-3 months, but disappeared by 6 months. The results demonstrate remarkable ability of homeostatic mechanisms to preserve normal plasma glucose and glucose tolerance in spite of dramatic changes in insulin and glucagon.
 ...
PMID:Hepatotoxicity induced by diethylnitrosamine causes no significant disturbances of systemic glucose homeostasis in rats. 217 90

In a 106-wk toxicity and carcinogenicity study, groups of 60 male and 60 female weanling Wistar rats were fed 0, 0.5, or 50 mg bis(tri-n-butyltin)oxide (TBTO)/kg diet. In males, feed consumption was increased in all treated groups and increased water consumption occurred at 5 and 50 mg/kg. During the second year, body weight decreased in the 50-mg/kg males, while the females in that group showed no weight gain. Excess mortality was confined to the 50-mg/kg group towards the end of the study. Haematological changes, comprising anaemia, lymphocytopenia and thrombocytosis were noted mainly at the high-dose level. Also, signs of decreased kidney function and increased plasma enzyme activities (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase) were noted. No effects on serum hormone concentrations (thyrotropin, follicle stimulating hormone, luteinizing hormone or insulin) were observed, except for a decrease in the free thyroxin:thyroxin ratio in both sexes at the high-dose level. Higher serum IgM and IgA levels were present at 50 mg/kg, while, in females, IgG was decreased. At 50 mg/kg, the ovaries, adrenals, spleen (females), heart (males), pituitary, liver and kidneys were increased in weight, but the thyroid weight was decreased in females. The total tin concentrations in liver and kidneys showed a dose relationship and, in general, the concentrations were similar after 1 and 2 yr. Non-neoplastic histological alterations after 1 yr consisted of a decrease in the cell height of the thyroid follicles in all dose groups, with a reduced number of psammoma bodies at 50 mg/kg, a decrease in splenic iron content at 5 (females only) and 50 mg/kg, and a slight bile-duct activation. After 2 yr, only the thyroid changes were still present. In addition, at 2 yr, vacuolation and pigmentation of the proximal tubular epithelium and nephrosis were enhanced at 50 mg/kg. The incidence of benign tumours of the pituitary was significantly elevated and enhanced at 0.5 and 50 mg/kg. At 50 mg/kg increases in pheochromocytomas in the adrenal medulla and in parathyroid adenomas (males) were noted, while adrenal cortical tumours were decreased (males). There was a low, non-dose-related incidence of pancreatic carcinoma. Other tumour rates were in line with control data. It is concluded that lifetime feeding of 50 mg TBTO/kg diet induces toxicity in various organ systems. An increase in some common tumours was found at the high dose, probably due to hormonal or immunological changes.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Chronic toxicity and carcinogenicity of bis(tri-n-butyltin)oxide (TBTO) in the rat. 234 92

Glucocorticoid hormones increase the activity of cytosolic aspartate aminotransferase (cAspAT) in the Fao rat hepatoma cell line. Maximal increase (6-10-fold) was observed 48 h following the addition of the glucocorticoid agonist dexamethasone at a concentration of 0.1 microM. The effect of dexamethasone was specific since it was not mimicked by sex steroids and was inhibited by the glucocorticoid antagonist RU 486. Insulin (0.1 microM) inhibited by more than 50% the induction of cAspAT by glucocorticoids. The cAMP analog, 8-bromoadenosine 3',5'-monophosphate (Br8cAMP, 0.5 mM), potentiated the effect of dexamethasone (2-3-fold) and partially relieved the inhibitory effect of insulin on the induction by dexamethasone. Both insulin and Br8-cAMP had no significant effect on basal activity. The mitochondrial isoenzyme was insensitive to the various hormonal treatments. Northern blot analysis revealed the presence of two major (2.1-kb and 1.8-kb) and one minor (4-kb) mRNA species hybridizing with a rat cAspAT probe. The regulation of these mRNAs by glucocorticoids, insulin and cAMP correlated with the variation of the cAspAT activity, suggesting that these hormones act at the pretranslational level. We compared the regulation of cAspAT mRNAs with those of tyrosine aminotransferase mRNA. Both were similarly increased by dexamethasone but the latter was also increased by cAMP even in the absence of the glucocorticoid agonist. In addition, the increase in tyrosine aminotransferase mRNA was inhibited by cycloheximide whereas the increase in cAspAT mRNAs was not. These results show that there are significant differences in the regulation of cAspAT and tyrosine aminotransferase by glucocorticoids and other hormones, although both enzymes probably contribute to the same metabolic pathway.
 ...
PMID:Regulation of cytosolic aspartate aminotransferase mRNAs in the Fao rat hepatoma cell line by dexamethasone, insulin and cyclic AMP. 255 14

The activity of glutamate related enzymes and the concentration of glutamine, glutamate and gamma-amino n-butyric acid (GABA) were investigated in the cerebral cortex of rats, in different stages of insulin-induced hypoglycemia. Hypoglycemia was produced by intraperitoneal injection of insulin 0.05-100 units per kg body weight. The minimum required dose to produce irreversible severe hypoglycemia was 0.5 units/kg. In 85% of the cases an insulin induced hypoglycemic convulsion, was achieved 130-150 minutes after injection. Blood glucose levels during insulin induced seizures ranged between 8-15 mg%. In the range of 0.5-100 u insulin/kg the degree of hypoglycemia and the onset of convulsions were identical. The concentration of glutamine was significantly reduced during convulsive and postconvulsive stages. Glutamate and GABA concentrations were reduced significantly in all stages of insulin-induced hypoglycemia. The decrease in glutamine concentration was concurrent with an increase in the activity of its degradative enzyme, glutaminase. This was apparent at the preconvulsive, convulsive and postconvulsive stages. The activity of other enzymes related to energy production such as glutamate dehydrogenase (GDH), glutamate transaminase (GPT) and aspartate aminotransferase (AAT) were also increased. The activity of glutamine synthase (GS) was unaffected by hypoglycemia. Insulin induced changes in glutamine, glutamate and their related enzymes could not be attributed to convulsion since a similar pattern of changes was observed in the preconvulsive and postconvulsive stages, and no changes were detected following picrotoxin-induced seizures.
 ...
PMID:Changes in the activity of glutamate related enzymes in cerebral cortex, during insulin-induced seizures. 257 18

It is well established that caloric restriction extends life span and significantly retards the rate of occurrence of most age-associated degenerative disease processes. A paucity of data exists relative to the mechanisms by which caloric restriction accomplishes these events. We have examined the effect of caloric restriction in rats on several hepatic enzymes of intermediary metabolism. The activities of glycolytic and supporting enzymes including lactate dehydrogenase, pyruvate kinase, sorbitol dehydrogenase, and alcohol dehydrogenase were all decreased in response to caloric restriction. Fructose 1-phosphate aldolase and creatine phosphokinase were not altered. Likewise, enzymes associated with lipid metabolism (malic enzyme and glycerokinase) were reduced (fatty acid synthetase was reduced, but not to a statistically significant degree). Activities of enzymes supporting gluconeogenesis (glutamate oxaloacetate transaminase, tyrosine aminotransferase, glutamate pyruvate transaminase, glutamate dehydrogenase, amino acid oxidase, malate dehydrogenase, and glucose 6-phosphatase) were either unchanged or increased significantly by caloric restriction. Glucagon levels were decreased. Comparisons between young ad libitum fed and older calorically restricted rats revealed similar but not identical metabolic activity. These results suggest that caloric restriction produces an effect on intermediary metabolism, favoring the role of glucagon and glucose synthesis; but limiting the role of insulin and glucose catabolism in the liver. The former observation provides for the efficient support of peripheral tissues and the latter a level of energy production necessary only for self maintenance. Limited lipid metabolism suggests decreased potential for fatty acid epoxide formation and free radical damage to cellular macromolecules. Additionally, caloric restriction may delay the progressive age associated changes in the activities of some of the enzymes investigated.
 ...
PMID:Effect of chronic caloric restriction on hepatic enzymes of intermediary metabolism in the male Fischer 344 rat. 266 33

The early stages of insulin-dependent diabetes mellitus are characterized by a selective inability to secrete insulin in response to glucose, coupled to a better response to nonnutrient secretagogues. The deficient glucose response may be a result of the autoimmune process directed toward the beta-cells. Interleukin-1 (IL-1) has been suggested to be one possible mediator of immunological damage of the beta-cells. In the present study we characterized the sensitivity of beta-cells to different secretagogues after human recombinant IL-1 beta (rIL-1 beta) exposure. Furthermore, experiments were performed to clarify the biochemical mechanisms behind the defective insulin response observed in these islets. Rat pancreatic islets were isolated and kept in tissue culture (medium RPMI-1640 plus 10% calf serum) for 5 days. The islets were subsequently exposed to 60 pM human recombinant IL-1 beta during 48 h in the same culture conditions as above and examined immediately after IL-1 exposure. The rIL-1 beta-treated islets showed a marked reduction of glucose-stimulated insulin release. Stimulation with arginine plus different glucose concentrations, and leucine plus glutamine partially counteracted the rIL-1 beta-induced reduction of insulin release. The activities of the glycolytic enzymes hexokinase, glucokinase, and glyceraldehyde 3-phosphate dehydrogenase, were similar in control and IL-1-exposed islets. Treatment with IL-1 also did not impair the activities of NADH+- and NADPH+-dependent glutamate dehydrogenase, glutamate-aspartate transaminase, glutamate-alanine transaminase, citrate synthase, and NAD+-linked isocitrate dehydrogenase. The oxidation of D-[6-14C]glucose and L-[U-14C]leucine were decreased by 50% in IL-1-treated islets. Furthermore, there was a significant decrease in the ratios of [2-14C]pyruvate oxidation/[1-14C]pyruvate decarboxylation and L-[U-14C]leucine oxidation/L-[1-14C]leucine decarboxylation, indicating that IL-1 decreases the proportion of generated acetyl-coenzyme-A residues undergoing oxidation. However, in the presence of IL-1 there was a significant increase in L-[U-14C]glutamate oxidation. These combined observations suggest that exposure to IL-1 induces a preferential decrease in glucose-mediated insulin release and mitochondrial glucose metabolism. This mitochondrial dysfunction seems to reflect an impairment in proximal steps of the Krebs cycle. It is conceivable that the IL-1-induced suppression and shift in islet metabolism can be an explanation for the beta-cell insensitivity to glucose observed in the early phases of human and experimental insulin-dependent diabetes mellitus.
 ...
PMID:Differential sensitivity to beta-cell secretagogues in cultured rat pancreatic islets exposed to human interleukin-1 beta. 266 6


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>