Fatty Acid Compositions in Glycerophospholipids from Brain Lobes of Rainbow Trout, Carp and Skipjack Tuna

The fatty acid composition of glycerophospholipids extracted from certain brain lobes and optic nerves of rainbow trout, a cold freshwater fish, carp, a relatively warmer freshwater fish, and skipjack tuna, a relatively warm seawater fish, was investigated. The telencephalon, optic tectum and cerebellum of all species contained almost similar level of 22:6n-3 in glycerophospholipids, except for the carp telencephalon. Glycerophospholipids of rainbow trout tissues were relatively richer in total levels of monoenoic fatty chains, such as 18:1n-9, 24:1n-9, and 18:1 dimethylacetal, than those of carp and skipjack tuna. These results suggest that the level of 22:6n-3 in glycerophospholipids should be differentiated not by temperature adaptation but by physiological functions of the nervous tissues.