THE EFFECT OF DIETARY-LIPID CHANGES ON THE FATTY-ACID COMPOSITION ANDFUNCTION OF LIVER, HEART AND BRAIN MITOCHONDRIA IN THE RAT AT DIFFERENT AGES

A correlation between dietary lipids and cellular enzyme activities is a problem that has only been partially addressed by nutritionists. Th erefore, changes in the fatty acid composition and the activities of s ome key metabolic enzymes (ubiquinol-2-cytochrome c reductase (EC 1.10 .2.2), cytochrome oxidase (EC 1.9.3.1) and ATPase (EC 3.6.1.3)) in the mitochondria of liver, heart and brain of rats fed on diets differing extensively in their polyunsaturated fatty acid compositions have bee n investigated. The results showed that fatty acid compositional chang es brought about by the dietary differences were associated with exten sive changes in the activities of these key enzymes in the mitochondri a. The extent of the influence differed considerably with the period o ver which the diets were fed. The role of dietary lipids to effect cha nges through the preservation of membrane structural integrity is disc ussed.