Hepatic microsomal drug metabolism, glutamyl transferase activity and in vivo antipyrine half-life in rats chronically fed an ethanol diet, a control diet and a chow diet

G Gadeholt, J Aarbakke, E Dybing, M Sjoblom and J Morland

The effects of chronic consumption of ethanol on several hepatic enzyme activities were investigated. Male Wistar rats (180 g) were divided in three groups, two of which were pair-fed ethanol or control liquid diets while the third group received chow and water ad libitum (untreated group). The following changes were observed after 1 and/or 6 weeks when expressed per 100 g b.w.: In the ethanol group, the amount of cytochrome P-450 increased as did the activities of aniline hydroxylase and glutamyl transferase. The in vivo half-life of antipyrine decreased. The activity of NADPH cytochrome c reductase in the ethanol group was different from the reference groups, but not changed compared to pre-experimental values. The activities of ethylmorphine N-demethylase and aryl hydrocarbon hydroxylase were decreased when expressed per gram of microsomal protein. In the control group, the activity of NADPH cytochrome c reductase declined and so did hepatic weight. The study gave support to a suspicion that feeding control diet may influence hepatic enzyme activities as well as relative liver weight. This influence may magnify ethanol effects on NADPH cytochrome c reducdase and relative liver weight when such effects are measured as the difference between the control and the ethanol group at single points of time. In addition, our study showed that ethanol should not be regarded as a general inducer of microsomal enzymes.

Volume 213, Issue 1, pp. 196-203, 04/01/1980
Copyright © 1980 by American Society for Pharmacology and Experimental Therapeutics