Lipogenesis from glucose-2- 14 C and acetate-1- 14 C in aorta.

Lipogenesis was measured with glucose-2-(14)C and acetate-1-(14)C in the everted aortas of normal and atherosclerotic rabbits. More glucose-2-(14)C than acetate-1-(14)C was incorporated into lipids in both the normal and the atherosclerotic aorta. Radiocarbon from glucose-2-(14)C appeared mainly in triglycerides and phospholipids with a small amount in cholesteryl esters. Incorporation increased almost threefold with atherosclerosis, most of the radioactivity being in the glycerol moiety; radioactivity was predominantly in carbon 2 of glycerol. About 70% of the acetate-1-(14)C incorporated into phospholipids and triglycerides was in the fatty acids, and the remainder was in glyceride-glycerol; 98% of the radioactivity in cholesteryl esters was in the fatty acid moiety. Incorporation into cholesteryl esters was increased most during the development of atherosclerosis. Fatty acid synthesis was similar from both acetate-1-(14)C and the 2 carbon unit derived from glucose-2-(14)C, viz., predominantly de novo synthesis of fatty acids with 14 and 16 carbon atoms, and elongation for those of 18 carbons and longer.