Liver desaturase activities and FA composition in monkeys: effect of a low-protein diet

Abstract

The aim of the present study was to measure ∆9-, ∆6-, and ∆5-desaturase activities in liver microsomes, as well as phospholipid FA composition of liver and erythrocytes in monkeys fed a control or low-protein diet during the postweaning period. Ten Saimiri sciureus boliviensis (Cebidae) of both sexes were employed; at 12 mon of age they were separated into two groups fed ad libitum on a control or a low-protein diet for 24 mon. Saimiri sciureus had active ∆9, ∆6, and ∆5 liver desaturase enzymes, and these activities were influenced by the diet. A low-protein diet produced a significant reduction in ∆5-desaturation capacity, an increase in ∆9-desaturase activity, and no change in ∆6-desaturase activity (P < 0.05). These changes, evoked by protein deprivation, were reflected in the liver phospholipid FA composition. Increases in the proportion of saturated FA and in monounsaturated oleic acid (18:1n-9) and a decrease in the proportion of PUFA of the n-6 and n-3 series were produced in the animals fed a low-protein diet (P < 0.0001). Differences between the two dietary groups were less pronounced in the FA composition of erythrocyte phospholipids