Age-related changes in plasma and tissue fatty acid composition in Fischer 344 rats.

Advancing age is associated with increased risk of coronary artery disease. Changes in fatty acid metabolism affect important cellular membrane properties and functions which may contribute to the vascular pathophysiology of aging. This study was designed to investigate the effects of aging on the fatty acid composition of the plasma, liver, aorta, and renal artery in 4-, 15-, and 24-month old Fischer 344 rats, an animal model for aging. With aging, the levels of total polyunsaturated fatty acids (PUFA) increased in the plasma, aorta, and renal artery. The major changes in the liver fatty acid profile were increases in the levels of 18:2n6 and 18:3n3 and a decrease in the levels of 20:3n6 and 20:5n3. The results indicate that significant shifts occur in the levels of n6 and n3 PUFA in the plasma, liver, and vasculature with aging. The alterations in the fatty acid composition may be a pathogenetic mechanism of the vascular changes associated with aging.