Manipulation of alkylglycerolipid levels in cultured cells. Fatty alcohol versus alkylglycerol supplements.

Ehrlich ascites cells and monolayers of L-M cell fibroblasts were grown in medium containing either long-chain fatty alcohols or alkylglycerols. The cells were then analyzed to determine the contribution of these lipid precursors to the synthesis of complex lipids for the purpose of defining the most efficient system to elevate the levels of ether phospholipids. Label from high specific activity [1-14C]hexadecanol, [1-14C]octadecanol, and [1-14C]octadecenol was incorporated into alkyl linkages (C-18 : 1 greater than C-16 : 0 greater than C-18 : 0); however, similar labeling of acyl groups occurred. Increasing the amount of hexadecanol in the growth medium resulted in a higher percentage of 14C-labeled acyl groups than alkyl linkages at all concentrations of the alcohol supplement. Supplements of rac-[1-14C]hexadecylglycerol to the growth media were assimilated into phospholipids, which significantly increased as a function of the amounts added. Mass determinations of the alkyl ether phospholipid content in L-M cells incubated for 24 h with an alkylglycerol mixture (10.8 microgram/ml) showed an approximate 70% increase over control levels; supplementation had only a slight effect on the alk-1-enyl content. The systems described will be useful for investigating biophysical and biochemical effects of alkyl ether enrichment in membranes.