Arterial effects of palmitic, linoleic and acetoacetic acid

The ultrastructural effects of a single brief intra-arterial infusion of palmitic, linoleic and acetoacetic acid on the arterial endothelium of the rat were investigated, and the following results obtained: (1) Palmitic acid, infused at a concentration of 4 mM/l, damaged the arterial lining by producing large cytoplasmic clefts and occasional blebbing and lysis of the endothelial cells. By contrast, linoleic acid, infused at the same concentration, had no damaging effects on arterial endothelium. (2) Acetoacetic acid damaged the arterial wall when infused at concentrations of 0.2 mM/l or higher by inducing extreme swelling and loss of cristae of the mitochondria in arterial endothelium and myocytes. The above results raise the possibility that (a) high saturated fatty acid diets may promote atherosclerosis not only by inducing hypercholesterolemia but also by injuring the arterial lining, and (b) diabetes may promote atherosclerosis not only by inducing hyperlipemia but also by damaging the arterial wall during periods of uncontrolled ketoacidosis.