Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic ammonia toxicity in experimental mice was induced by exposing them for 2 and 5 days to 5 % (v/v) ammonia solution. The enzymes concerned with glutamate metabolism (aspartate-, alanine- and tyrosine aminotransferases, glutamate dehydrogenase and glutamine synthetase) and (Na+ + K+)-ATPase were estimated in the three regions of brain (cerebellum, cerebral cortex and brain stem) and in liver. Glutamate, aspartate, alanine, glutamine and GABA, RNA and protein were also estimated in the three regions of brain and liver. A significant rise in the activity of (Na+ + K+)-ATPase in all the three regions of brain along with a fall in the activity of alanine aminotransferase was noticed. Changes in the activities of other enzymes were also observed. A significant increase in alanine and a decrease in glutamic acid was observed while no change was observed in the content of other amino acids belonging to the glutamate family. As a result of this, changes in the ratios of glutamate/glutamine and glutamate + aspartate/GABA was observed. The results indicated that the brain was in a state of more depression and less of excitation. Under these conditions the liver tissue was showing a profound rise in the activity of the enzymes of glutamate metabolism. The results are further discussed.
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PMID:Chronic metabolic effects of ammonia in mouse brain. 9 19

The crude protein levels as well as the activities of various enzymes were studied in certain tissues of fetuses (80th through 114th days of development), piglets of different age groups, and pigs for slaughter. In most of the tissues tested the postnatal activities of Na-K-ATPase were beyond those recorded from fetuses. The highest GOT activities were recorded from the liver, myocardium, and kidneys. Activities were found to rise sizeably in some tissues after birth. The activity of GPT, too, exhibited age-dependent variations. The activity of leucine-aminopeptidase increased strongly after birth in liver and kidneys. Acid phosphatase activity was less markedly influenced by development phases. Those enzymes which are involved in the formation of fructose and glucose (aldolreductase, glucuronate-reductase, and sorbite-dehydrogenase) had their highest activities, all age-dependent, in liver and kidneys.
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PMID:[Enzyme arrangement of various tissues in swine. 3. Studies of pre- and postnatal activities of various enzymes (ATPase, GOT, GPT, leucine aminopeptidase, acid and alkaline phosphatases, aldose reductase, glucuronate reductase, sorbitol dehydrogenase) in various tissues]. 22 27

Paraoxon in doses of one LD50 (0.426 mg/kg), eight times and eighty times LD 50 was applied s.c. to female Sprague-Dawley rats. After 3, 6, 10, 24 and 36--48 h the activities of enzymes GOT, GPT, GLDH, SDH, CPK and ChE were measured, once after i.m. antidote application of Toxogonin only, of Toxogonin + atropine and the next one after application of combination Toxogonin + atropine + Solcoseryl (low-molecular components of deproteinized blood from young calves. The values obtained showed that in spite of treatment with Toxogonin or Toxogonin + atropine the activities of the enzymes increased; this enhancement could be prevented by addition of Solcoseryl to Toxogonin + atropine. The ChE-activity after 36 h was equivalent to that of the control value. The effect of paraoxon in the initial phase of poisoning was discussed in connection with hypoxia and acidosis resulting from a respiratory insufficiency as well as the inhibition of ATPase-activity with restriction of the energy metabolism following: consequently the effect of Solcoseryl was interpreted as an activation of the disturbed energy metabolism.
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PMID:[Phosphoric acid ester poisoned rats after antidote therapy. 2. Determination of serum enzyme activity]. 58 4

Ubiquinol-1 in aerated aqueous solution inactivates several enzymes--alanine aminotransferase, alkaline phosphatase, Na+/K(+)-ATPase, creatine kinase and glutamine synthetase--but not isocitrate dehydrogenase and malate dehydrogenase. Ubiquinone-1 and/or H2O2 do not affect the activity of alkaline phosphatase and glutamine synthetase chosen as model enzymes. Dioxygen and transition metal ions, even if in trace amounts, are essential for the enzyme inactivation, which indeed does not occur under argon atmosphere or in the presence of metal chelators. Supplementation with redox-active metal ions (Fe3+ or Cu2+), moreover, potentiates alkaline phosphatase inactivation. Since catalase and peroxidase protect while superoxide dismutase does not, hydrogen peroxide rather than superoxide anion seems to be involved in the inactivation mechanism through which oxygen active species (hydroxyl radical or any other equivalent species) are produced via a modified Haber-Weiss cycle, triggered by metal-catalyzed oxidation of ubiquinol-1. The lack of efficiency of radical scavengers and the almost complete protection afforded by enzyme substrates and metal cofactors indicate a 'site-specific' radical attack as responsible for the oxidative damage.
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PMID:Enzyme inactivation by metal-catalyzed oxidation of coenzyme Q1. 135 46

Embryonal nervous tissue from Wistar rats was transplanted into male rats of Wistar and August strains. Activity of eight enzymes belonging to various systems was estimated in brain cortex of rats recipients within 36 days after the transplantation. Lactate dehydrogenase, alanine aminotransferase, acid phosphatase, 5'-nucleotidase, ATPase and aldolase exhibited the dissimilarly decreased rate of activity in brain cortex of Wistar rats after transplantation as compared with the enzymatic activity in intact animals of this strain, while activity of alkaline phosphatase and esterases hydrolyzing alpha-naphthyl acetate was increased. Activation of almost all the enzymes studied was found within 36 days in Wistar rats after the transplantation. The rate of activity of zonal esterase isoenzymes was higher in brain cortex of August rats after transplantation of embryonal nervous tissue from Wistar strain as compared with that of Wistar to Wistar rats transplantation. The data obtained suggest that tissues of donors affected definitely the enzymatic activity in brain cells of rats-recipients as activity of most enzymes studied was higher in brain cortex of donors as compared with that of recipients.
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PMID:[Specifics of changes in various groups of enzymes in rat cerebral cortex after interstrain transplantation of embryonal nerve tissue]. 141 28

It has been established in experiments on white rats that antituberculous drugs (isoniazid, rifampicin, ethambutol) given in toxic doses affect the liver, its membranes and organelles, inhibit bile production and bioenergy. This is supported by activation of aspartate and alanine aminotransferases, (ALT and AST), alkaline phosphatase in blood serum and acid phosphatase in the liver, by a decrease of the activity of Na(+)-, K(+)-ATPase, succinate dehydrogenase and cytochromoxidase in the liver, lowering of the rate of bile secretion, excretion of bile acids, bilirubin and cholesterol with bile. Provided the drugs are administered in combination, the hepatotoxicity rises, particularly in combination of isoniazid with rifampicin, and especially as isoniazid is combined with rifampicin and ethambutol.
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PMID:[The comparative action of isoniazid, rifampicin and ethambutol on liver function]. 142 54

Recent studies indicate that in animals with marked cardiac hypertrophy, there is depressed function of Ca2+ sequestration by myocardial sarcoplasmic reticulum (SR) because of down regulation of the Ca(2+)-ATPase gene. However, in several animal models we have observed enhancement of myocardial Ca2+ sequestration in response to chronic cardiac stimulation. We tested the hypothesis that in animals with mild cardiac hypertrophy, there is enhanced Ca(2+)-cycling activity by the SR Ca2+ pump and Ca(2+)-release channel. Because creatine kinase activity is consistently decreased in cardiomyopathy, we also determined whether enhanced Ca2+ cycling was accompanied by down regulation or inhibition of the creatine kinase system. Mild cardiac hypertrophy was induced by volume overload; 2% salt was added to the diet of 2-week-old turkey poults for 4 weeks. Compared with age-matched controls, volume overload resulted in 14.3% increase in heart weight and 21.5% increase in heart-to-body weight ratios. The hypertrophied heart had approximately 20% increased activities of the SR Ca2+ pump and the SR Ca2+ channel. Net Ca2+ transport was increased by 16.5%. Compared with controls and in contrast to several other myocardial enzymes, creatine kinase activity was diminished in the hypertrophied hearts by 23% and creatine content was decreased by 8%. Differences between groups were not detected for lactate dehydrogenase, aspartate transaminase, and alanine transaminase. We concluded that an early adaptation of the myocardium undergoing hypertrophy in compensatory response to functional overload is an enhancement of Ca2+ cycling activity by the Ca2+ pump and Ca2+ channel of the SR.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of mild cardiac hypertrophy, induced by volume overload in turkeys, on myocardial sarcoplasmic reticulum calcium-pump and calcium-channel activities and on the creatine kinase system. 165 61

A number of chemicals are known to potentiate the hepatotoxicity of carbon tetrachloride. The halocarbon trichloroethylene was shown in a previous study to enhance both carbon tetrachloride-induced toxicity and lipid peroxidation in isolated hepatocytes. In this study three other chlorocarbons have been investigated in order to determine whether this interaction was peculiar to trichloroethylene or common to chlorinated solvents. Hepatocyte suspensions were exposed to carbon tetrachloride at subthreshold levels of toxicity and various concentrations of 1,1,1-trichloroethane, tetrachloroethylene, and chloroform over an eightfold concentration range. Plasma membrane preparations were exposed to tetrachloroethylene and carbon tetrachloride and effects on Mg(2+)- and Na(+)-K(+)-ATPase activities determined. None of the treatments alone caused statistically significant toxicity. Combined treatments resulted in toxicity as demonstrated by potassium ion, alanine aminotransferase, and lactate dehydrogenase leakage from the cells on coincubation of carbon tetrachloride with each of the other halocarbons studied. Only tetrachloroethylene and chloroform were found to potentiate lipid peroxidation, however. In liver plasma membranes no changes in Na(+)-K(+)-ATPase were observed with any of the treatments and only the highest dose of tetrachloroethylene was able to inhibit Mg(2+)-ATPase activity. There was no increase in this inhibition on coincubation with carbon tetrachloride, which does not support involvement of ATPases in combined halocarbon toxicity. In conclusion, the data suggest a mechanism of action common to this class of chemical although its specific nature remains to be established.
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PMID:Potentiating effects of chlorinated hydrocarbons on carbon tetrachloride toxicity in isolated rat hepatocytes and plasma membranes. 182 22

The status of Na+ regulation was examined during early stages of alkylation insult to rat liver. Na+/K+-ATPase activity in plasma membranes declined by 52% within 3 hr of treatment with 850 mg/kg acetaminophen. This loss preceded the release of alanine aminotransferase (2880 +/- 1550 U/ml) and necrosis (2+) seen at 24 hr. Activities of 5'-nucleotidase and Mg2+-ATPase and recovery of plasma membranes were comparatively unchanged at 3 hr. Because damage to Na+/K+-ATPase appeared early in the pathogenesis of acetaminophen hepatotoxicity, loss of hepatocellular Na+ regulation could represent one of the critical molecular consequences of lethal alkylation by acetaminophen.
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PMID:Early inhibition of the Na+/K+-ATPase ion pump during acetaminophen-induced hepatotoxicity in rat. 244 17

Bass gill microsomal preparations contain a Mg2+-dependent Na+-stimulated ATPase activity in the absence of K+, whose characteristics are compared with those of the (Na+ + K+)-ATPase of the same preparations. The activity at 30 degrees C is 11.3 mumol Pi X mg-1 protein X hr-1 under optimal conditions (5 mM MgATP, 75 mM Na+, 75 mM HEPES, pH 6.0) and exhibits a lower pH optimum than the (Na+ + K+)-ATPase. The Na+ stimulation of ATPase is only 17% inhibited by 10-3M ouabain and completely abolished by 2.5 mM ethacrinic acid which on the contrary cause, respectively, 100% and 34% inhibition of the (Na+ + K+)-ATPase. Both Na+-and (Na+ + K+)-stimulated activities can hydrolyze nucleotides other than ATP in the efficiency order ATP greater than CTP greater than UTP greater than GTP and ATP greater than CTP greater than GPT greater than UTP, respectively. In the presence of 10(-3)M ouabain millimolar concentrations of K+ ion lower the Na+ activation (90% inhibition at 40 mM K+). The Na+-ATPase is less sensitive than (Na+ + K+)-ATPase to the Ca2+ induced inhibition as the former is only 57.5% inhibited by a concentration of 1 X 10(-2)M which completely suppresses the latter. The thermosensitivity follows the order Mg2+--greater than (Na+ + K+)--greater than Na+-ATPase. A similar break of the Arrhenius plot of the three enzymes is found. Only some of these characteristics do coincide with those of a Na+-ATPase described elsewhere. A presumptive physiological role of Na+-ATPase activity in seawater adapted teleost gills is suggested.
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PMID:Ouabain-insensitive Na+ stimulation of a microsomal Mg2+ -ATPase in gills of sea bass (Dicentrarchus labrax L.). 285 46


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