Fatty acid composition changes in mitochondrial membranes induced by dietary long chain fatty acids

Abstract

The cardiopathogenic effects of dietary rapeseed oil have been reviewed [ 11. Fatty infiltration of rat cardiac muscle observed after short periods of high erucic acid rapeseed oil feeding [2,3] may be related to a decreased efficiency of mitochondrial ATP synthesis [4-61. Similar feeding experiments have shown the preferential incorporation of erucic acid into mitochondrial cardiolipin [7], an integral component of cytochrome oxidase [8]. Therefore it is of interest to investigate whether a transition in mitochondrial membrane ,fatty acid composition corresponding to changes in mitochondrial function [6] can be related to rapeseed oil containing diets. Study of the relationship of essential fatty acids to structural and functional properties of biological membranes has been made [9161 but specific roles in mitochondrial membrane functions are not clear. However, it is known that: changes in unsaturated fatty acid composition of essential fatty acid depleted mitochondria significantly influence oscillation period and freedom of spin label motion, properties dependant upon large domains of the mitochondrial membrane [ 151, specific phospholipids are required for catalytic activity of mitochondrial enzymes [ 17191 and in addition, peroxidation of fatty acyl moieties has been correlated with the loss of metabolic function [ 16,201. In the present work changes in the fatty acid composition of cytochrome containing membrane fractions were correlated to diet. Increases in n-9