Effect of dietary ethanol and cholesterol on metabolic functions of hepatic mitochondria and microsomes from the monkey, Macaca nemestrina.

Abstract

Monkeys (Macaca nemestrina) were divided into four groups, and each group was fed a particular diet. The variables in the diets were as follows: diet A, 0.3 mg cholesterol/kcal nutrient; diet B, 1.0 mg cholesterol/kcal nutrient; diet C, 0.3 mg cholesterol/kcal nutrient, ethanol (36% of calories); diet D, 1.0 mg cholesterol/kcal nutrient, ethanol (36% of calories). Monkeys on the diets containing ethanol developed fatty liver. Mitochondria from ethanol-fed animals demonstrated significant decreases in uncoupler-stimulated, state 3, and state 4 succinate oxidation activity; respiratory control ratio; and ATP content. Liver microsomes isolated from the ethanol-fed groups demonstrated increased ethanol oxidizing activity with either NADPH or H2O2 as cosubstrate. Aniline hydroxylase and aminopyrine-N-demethylase activities were also elevated in ethanol-fed animals. The alterations in these functional properties were related primarily to ethanol in the diets. Cholesterol, while being less of a perturbant than ethanol, did elicit a significant decrease in cytochrome oxidase activity of mitochondria and a small but statistically significant increase in microsomal-associated ethanol oxidation activity. It appeared to potentiate the effect of ethanol in lowering mitochondrial respiratory control and ATP concentrations.