MOLECULAR-SPECIES OF ETHANOLAMINE PLASMALOGENS AND TRANSACYLASE ACTIVITY IN RAT-TISSUES ARE ALTERED BY FISH-OIL DIETS

Effects of dietary fish oil ethyl esters and alkyldiacetylglycerols (a n ether-linked lipid) on the distribution of subclasses of choline- an d ethanolamine-glycerophospholipids as well as effects on highly unsat urated molecular species of ethanolamine plasmalogens from brain, sple en, kidney, lung, and testis of rats were examined. Supplementation of ethyl ester concentrates of n - 3 fatty acids had no effect on the di stribution of subclasses in any of the tissues. However, the supplemen ts of 1-O-octadec-9'-enyl-2,3-diacetyl-sn-glycerol (diacetates of sela chyl alcohol) caused significant increases in the alkylacylglyceraphos phocholine and alkylacylglycerophosphoethanolamine subclasses from spl een and lung and in the alkylacylglycerophosphoethanolamine subclass f rom kidney. Dietary supplements of fish oil ethyl eaters reduced the a rachidonate-containing species of ethanolamine plasmalogens whereas mo lecular species having 20:5(n - 3), 22:6(n - 3), and/or 22:5(n - 3) ac yl groups were increased in the spleen, lung, and kidneys, but not bra in. In testicular tissue from rats fed the fish oil diets, the molecul ar species of ethanolamine plasmalogens containing 22:5(n - 6) acyl gr oups were reduced. An increase of ethanolamine plasmalogens with 18:1 alk-1-enyl moieties paired with highly unsaturated sn-2 acyl groups we re found in the tissues of rats fed the fish oil plus selachyl alcohol diacetate supplements. Rats on the diet containing fish oil ethyl est ers had significantly lower [H-3]alkyllysoglycerophosphocholine CoA-in dependent transacylase activity in spleen microsomes than controls. Th is suggests that supplements of n - 3 fatty acids interferes with the transacylation of arachidonate, an event that could seriously impair t he release of arachidonate and lysophospholipids (e.g., lyso-PAF) that are precursors of potent bioactive lipid derivatives.