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)

Reportedly, serum manganese concentrations increase after myocardial infarction, closely correlated with increased serum aspartate aminotransferase activity. However, these conclusions are apparently based on analyses of contaminated samples. Serum manganese concentrations after myocardial infarction have been re-investigated by neutron activation analysis, and no significant increase could be demonstrated. Because serum copper and zinc could be determined simultaneously, analyses for these trace elements are also reported, which confirm the findings of others. After myocardial infarction a statistically significant (0.02 smaller than P smaller than 0.05) increase in serum copper and a statistically significant (0.001 smaller than P smaller than 0.01) decrease in serum zinc were observed.
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PMID:Influence of myocardial infarction on serum manganese, copper, and zinc concentrations. 111 93

In addition to the normal carboxylation reaction, phosphoenolpyruvate carboxylase from Zea mays catalyzes a HCO3(-)-dependent hydrolysis of phosphoenolpyruvate to pyruvate and Pi. Two independent methods were used to establish this reaction. First, the formation of pyruvate was coupled to lactate dehydrogenase in assay solutions containing high concentrations of L-glutamate and aspartate aminotransferase. Under these conditions, oxalacetic acid produced in the carboxylation reaction was efficiently transaminated, and decarboxylation to form spurious pyruvate was negligible. Second, sequential reduction of oxalacetate and pyruvate was achieved by initially running the reaction in the presence of malate dehydrogenase with NADH in excess over phosphoenolpyruvate. After the reaction was complete, lactate dehydrogenase was added, thus giving a measure of pyruvate concentration. At pH 8.0 in the presence of Mg2+, the rate of phosphoenolpyruvate hydrolysis was 3-7% of the total reaction rate. The hydrolysis reaction catalyzed by phosphoenolpyruvate carboxylase was strongly metal dependent, with rates decreasing in the order Ni2+ greater than Co2+ greater than Mn2+ greater than Mg2+ greater than Ca2+. These results suggest that the active site metal ion binds to the enolate oxygen, thus stabilizing the proposed enolate intermediate. The more stable the enolate, the less reactive it is toward carboxylation and the greater the opportunity for hydrolysis.
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PMID:Hydrolysis of phosphoenolpyruvate catalyzed by phosphoenolpyruvate carboxylase from Zea mays. 163 56

Two trials were conducted to determine the effect of monensin in broiler litter on sheep receiving the broiler litter in their diets. Broiler litter from chickens fed monensin as a coccidiostat, and from chickens receiving no coccidiostat, was included at a level of 30% in 2 sheep diets. In a further 2 treatments, monensin (15 mg kg-1) was added to each of the 2 diets to give a 2x2 factorial experimental design. In the first trial, copper (20 mg kg-1 feed) was added to the diets. These lambs were fed individually at a slightly restricted level of intake. No differences between treatments were observed in feed intake, average daily gain or efficiency of feed utilisation or in the concentrations of zinc, iron and manganese in the liver, glutathione peroxidase in erythrocytes and creatine kinase concentrations in the plasma. Hepatic copper content and copper retention in the livers of the sheep receiving the added monensin were significantly higher (P less than 0.05 and less than 0.01 respectively) than in those not receiving added monensin. The aspartate transaminase and alkaline phosphatase concentrations in the plasma of these sheep were also higher (P less than 0.05) than in those not consuming added monensin. In the second trial, the lambs were group-fed according to treatment and received the diets on an ad lib basis. The mean intakes of the groups receiving the diets with the added monensin, were lower than the intakes by the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of monensin and its metabolites in broiler litter on sheep consuming the broiler litter. 177 Apr 87

The effect of manganese pretreatment on acute toxicity of fenitrothion (FTH) was investigated in male rats by assessing the degree of enzymatic alterations. Oral administration of FTH (260 mg/kg) markedly inactivated cholinesterase (ChE) and carboxylesterase and elevated the activities of acid phosphatase, alanine aminotransferase and aspartate aminotransferase in different tissues 3 h after dosing. Pretreatment of rats with manganese (10 mg/kg, i.p.) 3 days prior to FTH application (260 mg/kg, p.o.) significantly enhanced these enzymatic changes. The results indicate that inhibition of esterases and elevation in other enzymes induced by manganese are likely to contribute to the increased enzymatic alterations observed following combined treatment.
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PMID:Studies on the interaction between manganese and fenitrothion in rats. 359 Feb 18

Pretreatment with Mn2+ is known to produce tolerance to Cd2+-induced lethality. This study was designed to determine the mechanism of tolerance to Cd2+-induced lethality and hepatotoxicity following Mn2+ pretreatment. Rats given 36 mumoles Cd2+/kg, i.v., died within 10-20 hr while only one of nine rats pretreated with Mn2+ (250 mumoles/kg, s.c., 48 and 24 hr prior to Cd2+ challenge) died. Ten hours after Cd2+, plasma aspartate aminotransferase and sorbitol dehydrogenase activities were elevated markedly, and extensive histopathologic lesions of the liver were evident in control rats but not in Mn2+-pretreated rats. To examine the mechanism of this tolerance, distribution of Cd2+ to fourteen organs and the subcellular distribution in six organs were determined in control and Mn2+-pretreated rats. Two hours after challenge (31 mumoles Cd2+/kg, i.v., 0.75 microCi 109Cd2+/mumol Cd2+), the distribution of Cd2+ to liver markedly increased after Mn2+ pretreatment with concomitant decreases in other tissues. Mn2+ pretreatment also resulted in a marked difference in the hepatic subcellular distribution of Cd2+ with more present in cytosol and less associated with organelles. Gel-filtration chromatography indicated that most cytosolic Cd2+ was bound to a low molecular weight protein. Isolation and partial characterization of this protein suggest that it is identical to metallothionein (MT); it had a similar relative elution following gel-filtration chromatography, had low absorbance at 280 nm and, after separation into two isoproteins by DEAE A-25 anion exchange chromatography, had the same mobility after electrophoresis on non-denaturing polyacrylamide gels as Cd2+-induced metallothioneins. These data suggest that Mn2+ pretreatment reduces Cd2+-induced hepatotoxicity by altering the hepatic subcellular distribution of Cd2+ with more Cd2+ binding to MT in the cytosol. This decreased hepatotoxicity is probably responsible for tolerance to Cd2+-induced lethality.
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PMID:Mechanism of manganese-induced tolerance to cadmium lethality and hepatotoxicity. 399 53

1. A cereal-based diet containing 7.6 mg copper/kg was fed ad lib. to laying hens for up to 48 d. Four other groups were given the control diet to which was added hydrated copper sulphate to provide 250, 500, 1000 and 2000 mg added Cu/kg. 2. Hens were killed on day 0 and after 3, 6, 12, 24 and 48 d. Records were kept of body-weight, food consumption, egg production and egg weight. 3. After slaughter blood haemoglobin, packed cell volume, serum Cu and aspartate aminotransferase (AAT; EC 2.6.1.1) were measured. The liver, kidneys, a sample of breast muscle, oviduct, ovary and gizzard were weighed. Gizzard, spleen, liver and kidney tissue were examined histologically. 4. The Cu, zinc and iron concentrations of liver, kidneys and breast muscle and the manganese concentrations of liver and kidneys were determined. 5. Body-weight loss occurred at 500-2000 mg added Cu/kg diet. Egg production was depressed by level of added Cu and period of time on the Cu-containing diets. 6. Mean liver, kidney, oviduct and ovarian weights per unit body-weight were depressed by Cu in the diet and the effect increased with period of time on the diets. Mean gizzard weight per unit body-weight was increased by dietary added Cu and by time. 7. Cu concentrations in the liver were increased by dietary level of added Cu and period of time on the diet. Zn concentration in liver increased at 1000 and 2000 mg added Cu/kg diet and liver Fe concentration was increased at these levels. Histological examination of the gizzard indicated that the Cu content of the gizzard lining increased with dietary added Cu.
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PMID:Effects of level of dietary copper sulphate and period of feeding on the laying, domestic fowl, with special reference to tissue mineral content. 737 Feb 11

The effects of strenuous physical exercise on the serial changes in the haematological, biochemical and hormonal markers were investigated. A group of 14 soldiers, aged 24-36 years, took part in a military training course for about 13 weeks. After severe exercise stress, an increase (90%) in the number of peripheral blood leucocytes was observed. The degree of leucocytosis showed a close correlation with the values of some serum parameters, such as concentrations of aspartate aminotransferase (AST; r = 0.747), lactate dehydrogenase (LD; r = 0.748), blood urea nitrogen (r = 0.756), creatine kinase (CK; r = 0.637), manganese-superoxide dismutase (Mn-SOD; r = 0.508), alanine aminotransferase (ALT; r = 0.542) and uric acid (r = 0.538), and concentrations of urinary parameters, such as vanilmandelic acid (r = 0.429) and free cortisol (r = 0.437). The subjects showing prominent leucocytosis over 9500 cells.microliters-1 exhibited a lower concentration of serum cholinesterase than those who showed milder leucocytosis. The serum Mn-SOD concentration was closely correlated with the serial changes in serum concentrations of AST, ALT, LD and CK, indicating exercise-induced muscle and liver damage. The change in peripheral leucocyte number was assumed to be diagnostically informative and may be a prognostic marker, reflecting organ damage and restoration after strenuous physical exercise.
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PMID:Leucocytosis as a marker of organ damage induced by chronic strenuous physical exercise. 878 93

We present the first reported study of Ruta graveolens toxicity in 7-8-month-old Nubian goats. Oral administration of 5 g/kg bw per day of R. graveolens leaves caused tremor, dyspnoea, frequent urination, incoordination of movement, ataxia and recumbency, with death after 1-7 days. In goats receiving oral doses of 1 g/kg bw per day of the leaves, the course of toxicity was prolonged and the animals had pallor of the visible mucous membranes and loss in condition; one died on day 17, the others being slaughtered on days 41 and 46. The clinical effects were correlated with pathological changes in various organs, alterations in serum aspartate transaminase, creatine kinase, total protein, cholesterol, urea and other serum constituents, haematological values and the concentrations in the tissues of copper, iron, zinc, manganese, calcium and phosphorus.
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PMID:Preliminary observations on experimental Ruta graveolens toxicosis in Nubian goats. 1216 28

Two aspartate aminotransferase (EC 2.6.1.1) isoenzymes (AAT-1 and AAT-2) from Lupinus albus L. cv Estoril were separated, purified, and characterized. The molecular weight, pI value, optimum pH, optimum temperature, and thermodynamic parameters for thermal inactivation of both isoenzymes were obtained. Studies of the kinetic mechanism, and the kinetics of product inhibition and high substrate concentration inhibition, were performed. The effect of some divalent ions and irreversible inhibitors on both AAT isoenzymes was also studied. Native PAGE showed a higher molecular weight for AAT-2 compared with AAT-1. AAT-1 appears to be more anionic than AAT- 2, which was suggested by the anion exchange chromatography. SDS-PAGE showed a similar sub-unit molecular weight for both isoenzymes. The optimum pH (between 8.0 and 9.0) and temperature (60-65 degrees C) were similar for both isoenzymes. In the temperature range of 45-65 degrees C, AAT-2 has higher thermostability than AAT-1. Both isoenzymes showed a high affinity for keto-acid substrates, as well as a higher affinity to aspartate than glutamate. Manganese ions induced an increase in both AAT isoenzymes activities, but no cooperative effect was detected. Among the inhibitors tested, hydroxylamine affected both isoenzymes activity by an irreversible inhibition mechanism.
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PMID:Characterization of aspartate aminotransferase isoenzymes from leaves of Lupinus albus L. cv Estoril. 1229 33

The effect of fly ash inhalation (4h daily, 5 days a week) for 28 days on the deposition of metal ions and histopathological changes in the liver and serum clinical enzymes has been studied. The results showed an increase in the concentration of metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), and lead (Pb) in the tissues of exposed rats. The level of metals varied from metal to metal and from organ to organ. Level of serum enzymes such as serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, and alkaline phosphatase were increased in fly ash exposed rats using whole body inhalation exposure as compared to sham controls. Histopathological studies of rat liver exposed to fly ash revealed infiltration of mononuclear cells in and around the portal triads, which seems to be laden with fly ash particles. Hepatocytes showed necrotic changes such as pyknotic nuclei, karyorrhexis, and karyolytic. These changes were more towards the centrolobular areas than the midzonal and periportal areas. These findings demonstrate that the toxic metals of inhaled fly ash in rats may get translocated into extrapulmonary organs, become deposited and hence may manifest their toxic effects on different tissues.
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PMID:Effect of fly ash inhalation on biochemical and histomorphological changes in rat liver. 1716 87


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