Effect of chronic ethanol administration on enzyme and lipid properties of liver plasma membranes in long and short sleep mice

Authors

  • Thomas Zysset,

    1. Departments of Medicine and Pharmacology and the Division of Gastroenterology, Veterans Administration Medical Center and University of Colorado School of Medicine, Denver, Colorado 80262
    Current affiliation:
    1. Department of Clinical Pharmacology, University of Berne, CH-3010 Berne, Murtenstrasse 35, Switzerland
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  • Mark A. Polokoff,

    1. Departments of Medicine and Pharmacology and the Division of Gastroenterology, Veterans Administration Medical Center and University of Colorado School of Medicine, Denver, Colorado 80262
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  • Francis R. Simon M. D.

    Corresponding author
    1. Departments of Medicine and Pharmacology and the Division of Gastroenterology, Veterans Administration Medical Center and University of Colorado School of Medicine, Denver, Colorado 80262
    • Professor of Medicine, Head, Division of Gastroenterology, University of Colorado School of Medicine, 4200 E. 9th Avenue, Denver, Colorado 80262
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Abstract

Mechanisms of alcoholic liver disease are still ill defined. We evaluated in two outbred lines of mice whether chronic ingestion of ethanol alters the lipid composition and/or enzyme activity of liver plasma membranes. Two mouse lines with different sensitivities towards the hypnotic effect of ethanol, designated long sleep and short sleep, were fed a liquid diet containing ethanol for 30 days. Ethanol intake reached 30 gm per kg per day in both lines, and serum ethanol levels were similar. In addition, hepatic triglyceride levels were similarly increased 2-fold with ethanol feeding. The following effects of ethanol treatment were observed in liver plasma membrane fractions: (i) Na+, K+-ATPase was significantly increased to 26% above control in long sleep only; (ii) alkaline phosphatase activity was 2-fold increased in both lines; (iii) 5′-nucleotidase, leucine aminopeptidase and Mg2+-ATPase activities remained unchanged in both lines; (iv) unesterified cholesterol and total phospholipid contents were unaltered in both lines, and (v) cholesteryl esters were increased in both lines, but to a greater extent in short sleep (1.5 vs. 4-fold). Thus, chronic ethanol ingestion induces specific alterations in liver plasma membrane structure and function, suggesting that adaptive responses to ethanol may be determined in part by inherited factors.

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