Conversion of linolenic acid to .OMEGA.3-highly unsaturated fatty acids in marine fishes and rainbow trout.

Abstract

[1-14C] 18:3 ω3 was administered to red sea bream, black sea bream, opaleye, stripped mullet, and rainbow trout, after 3 months of pre-feeding with a diet containing pollack liver oil. On the 6th day after administration, the distribution of radioactivity in the tissue fatty acids was examined. The radioactivity of 22:6 ω3 fraction exhibited 14.5% and 3.6% of total activity in rainbow trout, but 4.9%-0.9% in marine fishes. From this finding, it is supposed that the slow conversion of 18:3 ω3 to 22:6 ω3 which is an essential fatty acid, in marine fishes is a cause of the difference observed in the essential role of 18:3 ω3 between marine fishes and rainbow trout.