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)

Dedifferentiated rat hepatoma variant cells of clone Faof1 fail to express most of the liver-specific functions characteristic of its line or origin, H4IIEC3. When Faof1 cells are cultivated for 48 hr in the form of aggregates two cell types can be recovered from monolayer cultures established from the aggregates: the majority of cells are similar to the Faof1 parental line, but a new cell type (designated dag) that adheres only weakly to the substrate is present at a frequency of 2--12 X 10(-2). Eight dag populations and eight clones are characterized as being different from Faof1 cells by the production of serum albumin, aldolase B and in some cases activity of alcohol dehydrogenase and alanine aminotransferase. No dag cells are recovered after 18 or 24 hours of aggregation, but after 48 or 96 hrs 1--5% of the cells give rise to clones of dag cells. During aggregation cells are committed to become dag cells but their new phenotype is expressed only after 5--12 days. The fraction of dag cells in colonies that grow out from aggregates suggests that dag transformation is not a clonal event. These experiments demonstrate that a transitory change in the culture conditions of Faof1 cells can lead to a heritable modification in phenotypic expression. Since dag cells fail to express the liver-specific gluconeogenic enzymes that permit cells to grow in glucose-free medium, it is possible to select from dag populations revertants in which expression of these activities is restored. The frequency of appearance of such dag revertants is not increased by the action of EMS.
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PMID:Dedifferentiated variants of a rat hepatoma: partial reversion induced by cell aggregation. 744 71

The effects of verapamil, a calcium channel blocker, on allyl alcohol (AA) hepatotoxicity were studied in vivo. AA administration induced an increase of serum alanine aminotransferase (ALT) concentration and liver necrosis by means of glutathione (GSH) depletion. Pretreatment with verapamil reduced the increase of ALT in plasma and the morphological signs of necrosis induced by AA administration. Verapamil did not affect GSH levels by itself but prevented the decrease of the tripeptide by AA. In vitro, but not in vivo, verapamil inhibited the activity of alcohol dehydrogenase (ADH), the key enzyme in the conversion of AA into the toxic metabolite acrolein. These data indicate that verapamil protects against AA toxicity, probably by preventing the production of acrolein, its reactive metabolite.
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PMID:Effect of verapamil on allyl alcohol hepatotoxicity. 890 40

Lipopolysaccharide (LPS), or bacterial endotoxin, causes liver damage at relatively large doses in rats. Smaller doses, however, may influence the response to other hepatotoxicants. The purpose these studies was to examine the effect of exposure to relatively all doses of LPS on the hepatotoxic response to allyl alcohol, which causes periportal necrosis in laboratory rodents through an known mechanism. Rats were pretreated with LPS (100 micrograms/kg) 2 hr before treatment with a minimally toxic dose of allyl alcohol mg/kg), and liver toxicity was assessed 18 hr later from activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma and from histologic changes in liver sections. Plasma ALT and AST activities were not elevated significantly in rats treated with vehicle, LPS, or allyl alcohol alone, but pronounced increases were observed in rats treated with LPS and allyl alcohol. Significant liver injury occurred as early as 2 hr after allyl alcohol treatment in LPS-pretreated rats and peaked at 6 hr. LPS treatment did not affect the activity of alcohol dehydrogenase and did not affect the rate of production of NADH in isolated livers perfused with allyl alcohol; thus, LPS does not appear to increase the metabolic bioactivation of allyl alcohol into acrolein. On the other hand, pretreatment with 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, abolished the hepatotoxicity of allyl alcohol in LPS-treated rats, indicating that production of acrolein was needed for LPS enhancement of the toxicity of allyl alcohol. Pretreatment of rats with gadolinium chloride (10 mg/kg), a known inactivator of Kupffer cell phagocytic function, decreased LPS augmentation of the response to allyl alcohol. These data indicate that LPS markedly enhances the hepatotoxic response to allyl alcohol. Furthermore, the results suggest that the LPS-induced enhancement of allyl alcohol hepatotoxicity occurs through a Kupffer cell-dependent mechanism.
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PMID:Bacterial endotoxin enhances the hepatotoxicity of allyl alcohol. 916 72

An increase of alcohol dehydrogenase activity is observed in patients with chronic alcoholism at the first stage of the disease under normal indices of activity of aldehyde dehydrogenase, aspartate- and alanine aminotransferase and thymol sample that evidences for the induction of alcohol dehydrogenase synthesis in the liver. At the second stage of alcoholism the activity of alcohol dehydrogenase, aspartate- and alanine aminotransferase, the index of thymol sample increase while activity of aldehyde dehydrogenase decreases that indicates to organic destructive changes in the liver. At the third stage of alcoholism one can observe the decrease in activity of alcohol dehydrogenase, aldehyde dehydrogenase and alanine aminotransferase relative to activity of these enzymes at the second stage, that can evidence for the increase of the possibility of the processes of synthesis of the liver. The correlation of alcohol dehydrogenase activity to that of aldehyde dehydrogenase in the process of formation and development of alcoholism is shifted towards the progressive accumulation of acetaldehyde. Parallel increase of dopamine concentration in blood creates conditions for formation of morphine-like alcaloides--products of condensation of acetaldehide with dopamine.
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PMID:[Dopamine content in blood and activity of alcohol-transforming enzymes in alcoholism]. 946 45

Since it has been reported that amino acids have alleviating effects on ethanol- and acetaldehyde-induced toxicity, we investigated the effect of liver hydrolysate derived from bovine liver on ethanol- or acetaldehyde-induced toxicity and deficiency models of mice and rats in the present study. Liver hydrolysate improved the deficiencies of beam walking and food intake of mice in a dose-dependent fashion when challenged with ethanol at the dose of 5 ml/kg, p.o. According to the analysis using selective inhibitors for alcohol dehydrogenase and acetaldehyde dehydrogenase, it has been suggested that this improvement effect of liver hydrolysate is mainly due to the reduction of acetaldehyde toxicity. No effect of liver hydrolysate was found in coma and death produced by orally treated ethanol at 10 ml/kg. In contrast, liver hydrolysate dose-dependently decreased the coma and death of mice administered acetaldehyde at 1.8 ml/kg, p.o. Furthermore, an increase in serum GPT activity, which was caused by twice oral administration of acetaldehyde at 1.2 ml/kg at interval of 1 hr, was inhibited by liver hydrolysate. These results suggest that liver hydrolysate has a protective effect against ethanol- and acetaldehyde-induced toxicity.
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PMID:[Effect of liver hydrolysate on ethanol- and acetaldehyde-induced deficiencies]. 955 50

The activities of classes I and II alcohol dehydrogenase isoenzymes were determined in the sera of patients with toxic hepatitis using class-specific fluorogenic substrates. The activities of total alcohol dehydrogenase and enzymes indicative of liver damage were also measured. We found a statistically significant increase of class I alcohol dehydrogenase isoenzymes. The increase in class I (two-fold) was similar to the increase of alkaline phosphatase. In a correlated study, we observed a good correlation of the activity of class II isoenzymes with alanine aminotransferase. The total alcohol dehydrogenase activity was enhanced and correlated with lactate dehydrogenase. These results demonstrated that the alcohol dehydrogenase and class I isoenzymes are indicatory enzymes of liver cell damage, and may be diagnostically useful in toxic hepatitis.
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PMID:Serum activities of classes I and II alcohol dehydrogenases in toxic liver damage. 956 31

The objective of this study was to determine the effects of a country liquor Toddy (Coconut palm wine) and an equivalent quantity of ethanol on liver function and lipid metabolism in utero. Female albino rats with an average weight of 125 +/- 5 g were exposed to Toddy from coconut palm (24.5 ml/kg body weight/day) and ethanol (0.52 ml/kg body weight/day) for 15 days before conception and during pregnancy. On day 13 and day 19 of gestation, altered liver function and hyperlipidemia were seen in the fetuses of both the treated groups. Altered liver function was evidenced by the increased activity of alcohol dehydrogenase, aldehyde dehydrogenase, glutamic oxaloacetic transaminase (aspartate amino transferase (GOT)), glutamic pyruvic transaminase (alanine amino transferase (GPT)). Hyperlipidemia was caused by increased biosynthesis since the incorporation of 14C acetate into lipids and activities of HMG CoA reductase and lipogenic enzymes were elevated. Toddy treated fetuses were more severely affected than those exposed to an equivalent quantity of ethanol. Toddy seemed to potentiate the toxicity induced by alcohol suggesting the role of non alcoholic components. Hepatic functions of the day 13 fetuses were effected to a lesser degree than those in the day 19 hepatic liver.
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PMID:Effect of in utero exposure of Toddy (coconut palm wine) on liver function and lipid metabolism in rat fetuses. 995 82

Groups of patients suffering alcoholism and narcomania were examined for the effect of intoxication on the blood serum enzymes of mainly liver origin: alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as on thymol test. It has been shown that in patients with the first stage of alcoholism one could observe only functional disturbances in the liver: the increase of ADH activity which evidences for the induction of its synthesis. In patients with the first stage of opium narcomania one can record total hyperenzymenia, decrease of de-Rimis coefficient at the expense of more considerable increase of ALT activity than that of AST, as well as the sharp increase of thymol test--these are the signs of destructive and metabolic disturbances in the liver. In patients with the second stage of alcoholism one can observe the decrease of ALDH activity under the increase of ADH, AST, ALT activity and high thymol test-these are the signs of toxical hepatitis. Destructive and metabolic changes increase in the liver in the patients with the second stage of narcomania.
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PMID:[Comparative analysis of the effects of alcoholism and opium addiction on liver function]. 1139 20

Cotreatment of rats with a low hepatotoxic dose (30.7 mg/kg, i.p.) of allyl alcohol (AA) and a higher, but nontoxic, dose (150 mg/kg, oral) of caffeine (CF) potentiated the hepatotoxicity of AA. This was verified by significantly higher levels of plasma alanine aminotransferase (ALT) activity and histopathologically greater severity of lesions in the periportal hepatocytes than those due to AA alone. Treatment of rats with 4-methylpyrazole (4-MP) (0.5 mmol/kg, i.p.) (an inhibitor liver alcohol dehydrogenase) for 30 minutes, followed by similar cotreatment with AA and CF, completely prevented the elevation of plasma levels of ALT and histological damage induced by cotreatment with CF and AA 24 hours following their administration. Severe liver damage induced by cotreatment with CF and AA was further, markedly enhanced by phenobarbital pretreatment (80 mg/kg, i.p., 3 days). Thus, extensive necrosis of periportal hepatocytes was noted, as well as edema and accumulation of inflammatory cells in the necrotic foci caused by such pretreatment. The depression of hepatic nonprotein sulfhydryls resulting from CF plus AA was much more severe than that caused by AA or CF alone and appeared as early as 30 minutes after administration. However, much less marked depletion of protein thiols was observed following similar treatments. Significant increase in lipid peroxidation (as measured by melondialdehyde [MDA] formation) was also observed in rat liver but only 24 hours after administration. The production ofMDA in the rat liver was significantly higher after administration of AA plus CF than after administration of AA alone. Pretreatment of rats with phenobarbital further significantly enhanced the formation of 2,4-dinitrophenylhydrazine (DNP)-reactive metabolite(s) (measured as DNP-acrolein adduct equivalents) in rat liver induced by AA (30.7 mg/kg) plus CF (150 mg/kg) within 1 hour following such treatment. Cotreatment with AA and a higher dose of CF resulted in significantly higher excretion of urinary thioethers or mercapturic acids than in rats treated with AA alone. Thus, these data suggest that an increased bioactivation pathway of acrolein involving a P450 mixed-function oxidase system caused by CF may be involved in such potentiating effects of CF on AA-induced hepatotoxicity in rats.
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PMID:Influence of caffeine on allyl alcohol-induced hepatotoxicity in rats. I. In vivo study. 1139 13

The effect of aminoguanidine (a selective inhibitor of inducible nitric oxide synthase) on allyl alcohol-induced liver injury was assessed by the measurement of serum ALT and AST activities and histopathological examination. When aminoguanidine (50-300 mg/kg, i.p.) was administered to mice 30 min before a toxic dose of allyl alcohol (75 microL/kg, i.p.), significant changes related to liver injury were observed. In the presence of aminoguanidine the level of ALT and AST enzymes were significantly decreased. All symptoms of liver necrosis produced by allyl alcohol toxicity almost completely disappeared when animals were pretreated with aminoguanidine at 300 mg/kg. Depletion of hepatic glutathione as a consequence of allyl alcohol metabolism was minimal in mice pretreated with aminoguanidine at 300 mg/kg. It was found that the inhibition of toxicity was not due to alteration in allyl alcohol metabolism since aminoguanidine did not effect alcohol dehydrogenase activity both in vivo and in vitro.
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PMID:Beneficial effect of nitric oxide synthase inhibitor on hepatotoxicity induced by allyl alcohol. 1183 31


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