Serum and Aortic Lipids in Rabbits Fed Cholesterol and Linoleic Acid Stereoisomers

Abstract

Rabbits fed 1 g of cholesterol and 6 g of elaidinized linoleic acid (a mixture of linoelaidic stereoisomers) daily for 84 days showed no higher concentration of free cholesterol, cholesterol ester, triglyceride, phosphatidyl ethanolamine, phosphatidyl serine, lecithin, sphingomyelin or other lipid fractions in their serum than did control rabbits fed 1 g cholesterol and 6 g linoleic acid for a similar period. In the rabbits fed the elaidinized linoleic acid the concentration of trans isomer after 84 days was 13.2 ± 11.3% in the serum cholesterol ester fatty acids and 11.3 ± 8.2% in the triglyceride fatty acids, whereas it was usually less than 2.5% in the phospholipid fatty acids. The rabbits fed elaidinized linoleic acid showed little, or no more, atherosclerosis of the aortic arch, no more atherosclerosis in the thoracic and abdominal aorta, and only a slightly higher cholesterol content in their aortas than did those rabbits fed natural linoleic acid and cholesterol. The relationship of these results to those of similar experiments in which supplements of elaidinized oleic acid or olive oil were fed with cholesterol to rabbits is discussed.