Lipid composition of Friend leukemia cells following induction of erythroid differentiation by dimethyl sulfoxide

The effects of dimethyl sulfoxide (DMSO)‐induced differentiation of Friend leukemia cells in vitro on the lipid composition of these cells have been examined. DMSO had no early effect on the incorporation of either [¹⁴C] glycerol or [³H] methyl choline chloride into the total lipids or individual phospholipids of Friend cells up to 240 min after addition of the inducer. Examination of DMSO‐diferentiated Friend cell phospholipids revealed a percentage composition which was similar to control cells, with phosphatidylcholine and phosphatidylethanolamine in both uninduced and differentiated cells accounting for over 75% of the total phospholipid. Sphingomyelin levels were significantly lower in Friend cells than in normal adult mouse erythrocytes, and differentiation of murine erythroleukemia cells resulted in a further lowering of this phospholipid. In contrast, a significant increase in the level of phosphatidylethanolamine occured as a result of maturation. Fatty acid analysis of major lipid classes of differentiated Friend cells showed significant reduction in saturation, but no alteration in chain length in comparison to undifferentiated cells. A pronounced decrease in the cellular content of both free and esterified cholesterol, which resulted in a 45% decrease in the ratio of cholesterol/phospholipids, occurred in cells differentiated by the polar solvent. The findings indicate that erythrodifferentiation induced by DMSO results in a variety of changes in the lipid composition of the membranes of Friend leukemia cells.