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)

Serum beta-hexosaminidase (Hex) isoenzymes analyzed by enzyme immunoassay were investigated in a group of alcoholics (n = 38) hospitalized for detoxication, in another group of alcoholics (n = 22) abstinent between 6 days and 10 years and in a reference group (n = 20). Hex "B" isoenzyme was elevated in all 38 patients hospitalized for detoxication but only 35 of these had total Hex values above the upper limit of the reference group. The Hex A isoenzyme, gamma-glutamyltransferase, and aspartate aminotransferase showed considerable overlap between these patients and the reference group. In the group of 22 abstinent patients only one had an increased level of Hex A, Hex "B," and total Hex, whereas 10 had gamma-glutamyltransferase values above the upper limit of the reference group. It is concluded that Hex "B" is a useful marker for alcohol abuse.
Alcohol Clin Exp Res 1991 Jun
PMID:Serum beta-hexosaminidase isoenzyme: a sensitive marker for alcohol abuse. 183 3

To study the effects of ethanol on the hepatotoxicity of N-nitrosodimethylamine (NDMA), 5 mg NDMA/kg body weight was injected intraperitoneally 3 times a week for 6 weeks into rats pair-fed liquid diets containing 36% of energy either as ethanol or as additional carbohydrates. Another group of rats was pair-fed with the same diets but injected with saline instead of NDMA. Co-administration of ethanol and NDMA produced much higher elevations of serum alanine and aspartate aminotransferase and glutamic dehydrogenase activities than the administration of either agent alone. The combined treatment also slightly increased focal necrosis, whereas other liver lesions (steatosis and fibrosis) and the functional impairment of mitochondrial respiration were not affected significantly. Microsomal low Km NDMA demethylation, as well as NDMA denitrosation, were inhibited markedly by incubation with an antibody against P450IIE1, suggesting the involvement of this alcohol-inducible P450 in both NDMA bioactivation reactions. The addition of ethanol inhibited P450-dependent demethylation and denitrosation of NDMA in liver microsomes, whereas both activities were enhanced markedly by chronic ethanol administration. At ethanol concentrations similar to those prevailing in the blood of alcohol-fed animals at the time of NDMA administration, hepatic microsomal demethylation and denitrosation remained significantly higher in ethanol-fed rats given NDMA than in controls. Our results suggest that bioactivation plays a critical role in the hepatotoxicity of NDMA and its aggravation by chronic alcohol consumption.
 ...
PMID:Effects of ethanol consumption on bioactivation and hepatotoxicity of N-nitrosodimethylamine in rats. 185 64

The effects of moderate alcohol intake on serum (SHEX)- and urinary beta-hexosaminidase (UHEX) were studied in ten healthy volunteers, who ingested 60 g of 100% ethanol daily for 10 days. The drinking period was preceded and followed by an abstinence period. Moderate drinking and abstinence were rapidly and significantly reflected on SHEX, while UHEX levels did not change significantly during the study. Gramma-glutamyl transpeptidase (GGT), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) decreased during the first abstinence period (P less than 0.05), but stayed thereafter at a constant level. It is concluded that SHEX may better reflect recent alcohol consumption than UHEX, GGT, ASAT or ALAT.
Drug Alcohol Depend 1990 Feb
PMID:The effects of moderate drinking and abstinence on serum and urinary beta-hexosaminidase levels. 196 91

Two decades of research in ethanol metabolism have culminated in the molecular elucidation of an ethanol-inducible cytochrome P450 (P450IIE1) which is not only involved with ethanol metabolism and ethanol tolerance, but also with the activation of a number of xenobiotics. The unique ability of P450IIE1 to activate xenobiotic agents now appears to be responsible for the increased susceptibility of the heavy drinker to hepatotoxic industrial solvents, commonly used drugs, over-the-counter medications and chemical carcinogens. It also explains some of the interaction of ethanol with nutritional factors, such as hepatic vitamin A: enhanced microsomal degradation of retinoids (together with hepatic mobilisation) promotes depletion. Treatment, however, is complicated by the fact that ethanol also enhances the toxicity of excess vitamin A. All pathways of ethanol metabolism result in the production of acetaldehyde, the toxicity of which has been reviewed (Lieber 1982). New aspects discussed here include the formation of acetaldehyde-protein adducts and an associated immune response that may play a pathogenic role. Also discussed are the implications of ethanol-induced alterations in microtubules, mitochondria and plasma membranes, as they relate, in part, to accompanying acetaldehyde-induced toxicity, to the production of free radicals or to lipid peroxidation-mediated injury associated with glutathione depletion. There is also depletion of S-adenosyl-L-methionine (SAMe). Administration of synthetic SAMe results in a partial correction of the SAMe depletion and a consequent restoration of glutathione levels. Other beneficial effects of SAMe include a significant attenuation of the increase in plasma aspartate transaminase and glutamate dehydrogenase activities. Mitochondrial damage, including giant forms, documented by light and electron microscopy, is also attenuated by SAMe. Thus, the new understanding of the pathophysiology of alcohol-induced liver damage has led to more successful therapy with drugs and nutritional factors.
 ...
PMID:Interaction of alcohol with other drugs and nutrients. Implication for the therapy of alcoholic liver disease. 208 78

Various aliphatic alcohols potentiate the toxicity of a wide range of xenobiotics including several haloalkanes. The present series of experiments were designed to test: (i) whether a single subtoxic dose of alcohol can potentiate CCl4 and CHCl3 hepatoxicity, and (ii) whether this potentiation leads to greater animal lethality. Selected members of a homologous series of straight chain alcohols were chosen for this study. Methanol, ethanol, isopropanol, t-butanol, pentanol, hexanol, octanol, decanol, and eicosanol at equimolar doses (10 mmol/kg) were tested in the present investigation. Each alcohol was administered orally to male Sprague-Dawley rats (175-250 g) 18 hr prior to a single oral administration of CCl4 or CHCl3. Liver injury was assessed by plasma transaminases (alanine aminotransferase, ALT; aspartate aminotransferase, AST) and histopathological examination of liver sections 24 hr after the halomethane treatment. None of these alcohols alone increased plasma ALT or AST significantly, whereas CCl4 or CHCl3 administration to alcohol-treated animals resulted in significant elevation of plasma transaminases. Eicosanol (20-carbon alcohol) did not potentiate the toxicity of either halomethane. Methanol, ethanol, isopropanol, and decanol in combination with CCl4 caused massive liver damage but failed to augment CCl4 lethality. t-Butanol, pentanol, hexanol, and octanol significantly decreased the LD50 of CCl4. The hepatotoxic effects of CHCl3 were potentiated by all of the alcohols and the LD50s were also decreased significantly. On a comparative basis, alcohol-potentiated CHCl3 toxicity was greater than the toxicity of CCl4. These findings indicate that even though halomethane liver injury might be potentiated by alcohols, the underlying mechanisms differ among alcohols since not all alcohols potentiate the lethal effects of these halomethanes.
 ...
PMID:Potentiation of CCl4 and CHCl3 hepatotoxicity and lethality by various alcohols. 225 8

The present investigation examines the possibility that Cd and ethanol have a significant toxicological interaction. This examination was warranted as exposure to either chemical is known to compromise human health. Inasmuch as both chemicals affect the morphology, biochemistry, and physiology of liver, it seemed reasonable to consider liver as a possible site of interaction. Specifically, the hypothesis that ethanol alters the hepatotoxic action of Cd was evaluated. Accordingly, male rats were injected iv with hepatotoxic (3.0 mg/kg) or lethal (4.5 mg/kg) dosages of Cd, 24 hr after single-dose ethanol administration (7 g/kg, po). Cd-induced hepatotoxicity was assessed by measuring the activities of alanine aminotransferase, aspartate aminotransferase, and sorbitol dehydrogenase in serum collected 10 hr after Cd injection. Lethality was assessed by recording the number of survivors over a 7-day period. Prior exposure to ethanol substantially reduced the lethal and hepatotoxic properties of Cd. Two mechanisms were evaluated in an effort to explain ethanol-induced suppression of Cd hepatotoxicity. Ethanol pretreatment was postulated to: (1) enhance Cd excretion in bile thereby decreasing hepatic Cd content and/or (2) reduce the interaction between Cd and target sites in liver such as organelles and cytosolic high-molecular-weight (HMW) proteins. The first proposed mechanism was incorrect as the biliary excretion of Cd was nearly abolished and the concentration of Cd in whole liver increased (33%) as a result of ethanol exposure. The second proposed mechanism was a plausible explanation of ethanol-induced suppression of Cd hepatotoxicity because ethanol pretreatment decreased (approximately 60%) the content of Cd in nuclei, mitochondria, and endoplasmic reticulum, and nearly eliminated the association of Cd with cytosolic HMW proteins. Reduction in the concentration of Cd in potential target sites of intoxication was caused by a metallothionein-promoted sequestration of Cd in cytosol.
 ...
PMID:Ethanol decreases cadmium hepatotoxicity in rats: possible role of hepatic metallothionein induction. 226 92

Two recently proposed biochemical markers of alcoholism, namely, quantitation of plasma transferrin variant (Tf5.7) and the ratio of plasma mitochondrial aspartate aminotransferase (m-AspAT) to total AspAT (t-AspAT), were tested for their ability to detect young adult alcoholics. Another commonly used biochemical test, namely, activity of plasma gamma glutamyltransferase (GGT) was included as a comparison. Although mean values of GGT, TF5.7, total transferrin (Tftot), m-AspAT and t-AspAT in alcoholics were significantly higher than those in controls, there were too many overlapping values in each test between alcoholics and controls to render any of these tests suitable as a marker for young adult alcoholics. Depending on cut-off limits, the sensitivity of each test ranged from 0-52% and the specificity ranged from 80-97%. Moreover, the m-AspAT/t-AspAT and Tf5.7/Tftot ratios were not significantly different between alcoholics and controls. A stepwise linear discriminant function analysis of all the variables resulted in a slight increase in classification sensitivity (66%) but a decrease in specificity (77%). The relatively short duration (mean = 5.6 years) of heavy alcohol intake and the time elapsed (mean = 5.8 days) since the alcoholics last consumed alcohol very likely contributed to the low sensitivity. Young adults might also be more resilient with regard to the damaging biochemical effects of ethanol. Abnormal biochemical values might reverse to normal values much more quickly in young adult alcoholics than in those who are older and have more years of alcohol abuse.
Drug Alcohol Depend 1989 Jan
PMID:Transferrin and mitochondrial aspartate aminotransferase in young adult alcoholics. 256 67

The 7 day-long intragastric administration of ethanol and ethyleneglycol in a dose of 1/3 DL50 was studied for its effect on the circadian variations of the aspartate aminotransferase activity (AST, EC 2.6, 1.1) in the liver, brain, myocardium and kidney of male rats. The ethanol and ethylene glycol administration reduced the mean circadian enzymic activity in the above organs. Moreover, ethanol significantly reduced the amplitude of circadian variations of the AST activity in the liver, brain and kidney, while ethylene glycol--in the liver, myocardium and kidney.
 ...
PMID:[The effect of alcohols on daily variations in aspartate amino- transferase activity in rat organs]. 258 42

To determine if impaired intestinal absorption contributes to the folate deficiency observed in chronic alcoholics, we assessed in vivo folate absorption in Hanford mini-pigs fed ethanol with an adequate diet. Sixteen minipigs were pair-fed diets supplemented with ethanol or sucrose to 60% of total calories for 11 mo. In the ethanol-fed pigs peak blood alcohol concentrations averaged 28 mmol/L, serum alanine transaminase and aspartate transaminase activities were elevated, and liver histology showed a centrilobular distribution of succinate dehydrogenase. Tissue folate concentrations were comparable in both groups. The jejunal uptake of folic acid, measured by intestinal perfusion, was similar in both groups of animals and was not affected by acute exposure to 445 mmol/L ethanol. The in vivo hydrolysis of polyglutamyl folate was reduced by 35% in one ethanol-fed minipig. Decreased hydrolysis of polyglutamyl folate may represent an early step in the development of folate deficiency in chronic alcoholics.
 ...
PMID:Folate absorption in alcoholic pigs: in vivo intestinal perfusion studies. 259 32

We studied the relationship between the ratio of serum aspartate aminotransferase (ASAT) to alanine aminotransferase (ALAT) and histologic changes in human and experimental alcoholic liver disease. The patient population included 52 hospitalized patients enrolled in a Veterans Administration Cooperative study. The experimental animal group consisted of male Wistar rats fed an ethanol-liquid diet. Of the 52 patients with alcoholic hepatitis, 33 had evidence of cirrhosis. The mean +/- SD for the ASAT/ALAT ratio in the group with alcoholic hepatitis and no cirrhosis was 1.47 +/- 0.84, the mean +/- SD in the group with hepatitis and cirrhosis was significantly higher (2.68 +/- 1.32, p less than 0.01). There was no difference in the ratio between the rats with and without liver fibrosis. The cause for the increased ASAT/ALAT ratio in serum in the presence of cirrhosis is unknown and may reflect more severe liver damage.
 ...
PMID:Serum aspartate aminotransferase to alanine aminotransferase ratio in human and experimental alcoholic liver disease: relationship to histologic changes. 270 13


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