Lysolecithin-induced Ca2+ uptake by pigeon red cells

Lysolecithin (LPC) induced a rapid but transitory increase in 45Ca2+ influx, and an abrupt 45Ca2+ net uptake by pigeon red cells. The effect on uptake was seen with doses of added lysolecithin calculated to be 2.1-8.4% of the cytoplasmic membrane phospholipid, well within the reported physiological range of 1-9%. Lysolecithin effects were not due to prelytic membrane changes nor action as a platelet activating factor agonist. Changes in the amino acids in the medium mimicking human homocysteinuria, an atherosclerosis risk factor, increased the lysolecithin effect. The findings are consistent with a role for lysolecithin in atherosclerosis.