ALTERATION OF BRAIN AND LIVER MICROSOMAL POLYUNSATURATED FATTY-ACIDS FOLLOWING DIETARY VITAMIN-E-DEFICIENCY

The effects of dietary vitamin E deficiency on fatty acid composition of brain and liver microsomes were studied in rats fed a vitamin E-deficient diet for 9 weeks. In brain microsomes, vitamin E deficiency resulted in a significant decrease in palmitic acid and total saturated fatty acids. Cervonic acid was increased. In contrast, no marked changes were observed in the levels of (n-6) polyunsaturated fatty acid (PUFA). In liver microsomes, vitamin E deficiency resulted in significant alterations in fatty acid composition: higher amounts of stearic acid and total saturated fatty acids, lower amounts of mono-unsaturated fatty acids, linoleic and dihomo gamma linoleic acids. In contrast, arachidonic acid was not altered. The overall decrease in the amounts of (n-6) PUFA was compensated by an increase in the level of (n-3) PUFA. It is concluded that vitamin E may alter the enzymatic activities of chain elongation-desaturation and the relationship between vitamin E and PUFA in brain and liver microsomes.