Influence of dietary fats on ultrastructure and fatty acid. Composition of swine arterial tissue.

The effects of trans-fatty acid-rich and saturated acid-rich diets on the fatty acid composition and morphology of swine arterial tissues were studied. Three groups of two-month-old swine were fed either a basal diet or a basal diet containing 8.3% margarine or butter for 4 months. The most significant change observed in the fatty acid pattern was the accumulation of 18 : 2 omega 6 and the suppression of both 20 : 4 omega 6 and 22 : 4 omega 6 acids in the aortic tissues of swine fed either butter or margarine as compared to swine fed the basal diet. Also, omega 6 metabolites were significantly decreased in swine fed diets containing butter or margarine, as compared to those fed a basal diet. The group of swine which were fed either butter or margarine containing diets suffered a significant increase in intimal thickening of the coronary artery compared to those fed the basal diet. These thickened intima were characterized by the presence of modified smooth muscle cells, lipid containing cells, and degenerated cells without stainable lipids. However, there was no significant difference in the incidence and extent of intimal thickening of the coronary arteries between swine fed either of the two fat containing diets.