Lipid composition of erythrocytes in various mammalian species

Abstract

Lipid distribution in the erythrocyte was investigated in several common mammals, including rat, rabbit, pig, dog, horse, sheep, cow, goat, cat and guinea pig. Lipids were extracted from fresh, thoroughly washed, whole packed cells. The lipids were purified by Sephadex column chromatography and separated by thin-layer chromatography. Infrared spectrophotometry was also used to identify components. The distribution of cholesterol, glycolipids, and the phospholipids is reported. Cholesterol was approx. 26% of total lipid in all species while phospholipids ranged between 50 and 70%. The glycolipids were considerably more variable, accounting for 5.3% of the lipids in the rabbit erythrocyte and 23.5% of the lipids in the horse erythrocyte. The glycolipid fraction was not analyzed in detail. The phospholipids were separated into the various classes, but neither vinyl nor glyceryl ether compounds were separated from diacyl derivatives. The phospholipids common to all species were phosphatidic acid, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, and sphingomyelin. There are, however, marked species variations in the relative abundance of these erythrocyte phospholipids. No lecithin was detected in sheep, cow, or goat. However, an as yet unidentified phospholipid was detected in these species.