Selective incorporation of n-3 and n-6 unsaturated fatty acids into animal cell phospholipids.

Abstract

The selective incorporation of n-3 and n-6 unsaturated fatty acids into phospholipids was investigated by changing the ratio of n-3 unsaturated fatty acids against n-6 unsaturated fatty acids in the medium where Chinese hamster V79-R cells were grown. Unsaturated fatty acids with lower degrees of unsaturation were abundantly incorporated into phosphatidylcholine independently of n-3 and n-6. Unsaturated fatty acids with higher degrees of unsaturation were more predominantly incorporated into phosphatidylethanolamine. When the difference in the numbers of double bond between unsaturated fatty acids was more than two, the unsaturated fatty acids with a higher degree of unsaturation was more selectively incorporated into phosphatidylethanolamine than the unsaturated fatty acids with a lower degree of unsaturation. By the analysis of molecular species, n-3 and n-6 unsaturated fatty acids with higher degrees of unsaturation were incorporated competitively into phosphatidylethanolamine. Finally, docosahexaenoic acid was incorporated into diacyl phosphatidylethanolamine more selectively than the other unsaturated fatty acids.