Abstract :
Several studies have demonstrated that angiotensin converting enzyme (ACE) inhibitors can inhibit the development of atherosclerosis in hypercholesterolemic normotensive animals. The effect has been observed with different ACE inhibitors and across a wide range of species including the Watanabe heritable hyperlipidemic (WHHL) rabbit, cholesterol-fed rabbit, monkey, minipig, and hamster. Various actions of these drugs have been proposed as contributing to the anti-atherosclerotic effects such as inhibition of growth or migration of arterial smooth muscle cells by reducing angiotensin II or increasing bradykinin and prostacyclin levels, improvement of endothelium-dependent function, inhibition of leukocyte adherence and/or penetration into the arterial intima, inhibition of oxidation of lipoproteins, and lowering of blood pressure. Our very recent studies in the WHHL rabbit with a small dose of the ACE inhibitor, trandolapril, which was adequate to reduce both serum and arterial ACE markedly but was insufficient to lower blood pressure, had no effect on aortic atherosclerosis. The findings suggest that the anti-atherosclerotic action of trandolapril may not be related directly or exclusively to arterial ACE inhibition but is associated with blood pressure reduction.
