Lipid composition of low-density lysosomal membrane fraction prepared from atheromatous aorta of cholesterol-fed rabbits.

The lipid composition of low-density lysosomal membranes prepared from atheromatous aorta was analyzed. Results showed that the molar ratio of free cholesterol to phospholipids was 2.4, the phospholipids contained 49% sphingomyelin and 4% phosphatidylethanolamine and the phosphatidylcholine contained 22% polyunsaturated fatty acids. These values for the lipid composition are very different from those for normal biological membranes. The involvement of alteration of lysosomal membranes in accumulation of cholesterol ester in atherosclerosis is discussed.