Effect of Different Dietary Levels of Essential Fatty Acids on Liver and Serum Lipids in the Rat

Abstract

Rats were fed diets with three different levels of essential fatty acids (EFA); 3.0, 0.75 and 0.07 cal·% for more than two generations. The concentrations of serum phospholipids and cholesterol rose during the suckling period and fell rapidly after weaning. In the liver the triglycerides reached their highest value early in the suckling period. The concentration of the triglycerides was the same in the EFA-deficient groups as in the control group. The fatty acid patterns of serum and liver lecithins in the four dietary groups were similar in several respects, but the concentration of the highly unsaturated fatty acids, primarily arachidonic and docosahexaenoic acids, were higher in the liver. The largest deficiency of EFA in serum and in liver was found at birth and during the late suckling and early postsuckling periods. This deficiency was compensated for mainly by an increase in the fatty acid 20:3 (n-9) as well as in the monoenoic acids 16:1 and 18:1. The proportions of fatty acids of the linolenic acid series were reduced more than those of the linoleic acid series at all ages, both in the groups which received 0.75 and in those which received 0.07 cal% EFA.