Effects of Chronic Alcohol Feeding on the Lipid Contents in the Rat Liver and the Hepatic Microsomal 2-Acetylaminofluorene(1-AAF) Hydroxylation in Vitro

It is now well established that ethanol excerts different effect on hepatic cellular metabolism, depending mainly on the duration of its intake. And induction of quantitative and qualitative alterations in the cytochrome P-450 of hepatic microso-mes after chronic ethanol feeding is a well-documented phenomenon. But the effect of ethanol ingestion on the drug metabolism appear paradoxic and the ability of chronic ethanol ingestion to potentiate the carcinogenicity of 2-acetyl-aminofluorene(2-AAF) by microsomal activation is not confirmed yet. The present study was undertaken to demonstrate the effects of 15%, 30% ethanol and a commercial liquor feeding for 16 weeks on the lipid in the rat liver, hepatic microsomal cytochrome P-450 and b5, and to elucidate whether or not ethanol-induced rat microsomes can increase the risk of cancer by increasing the rate of metabolic activation of 2-AAF in vitro. The results are followings. 1) The chronic alcohol feeding increased the contents of total cholesterol and triglyceride in the liver, but did not make a significant influence on the phospholipid contents of liver. 2) The 8 week alcohol feeding increased the hepatic microsomal cytochrome P-450 without the changeof cytochrome b5 but the 16 week feeding decreased P-450 significantly. 3) The chronic alcohol feeding elevated the AAF N-hydroxylation continuously but did not influence on AAF ring-hydroxylation. 4) The correlation of AAF N-hydroxylation and the increases of hepatic lipid contents was indicated.