Fatty liver induction: effect of ethionine on polyunsaturated fatty acid synthesis

Abstract

Hepatic synthesis of unsaturated fatty acids in vivo or in vitro is not directly effected by inclusion of low levels of ethionine in the diet of the rat. Experiments may be designed to produce apparent reproducible increases or decreases in hepatic microsomal linoleie acid desaturase activity in vitro or of [1- 14C]acetate incorporation into phospholipid polyunsaturated fatty acids in vivo. The effect noted in vitro may be related to a greater susceptibility of the hepatic microsomes to damage during isolation whereas the effect noted in vivo is a by-product of neutral lipid accumulation. Similar results were also obtained in less detailed experiments with rats fed orotic acid. Neither hepatotoxin appeared to enhance lipofuscin or ceroid pigment formation although ethionine did significantly effect the hepatic microsomal mixed function oxidase system.