ABSTRACT
Objective: To study the attenuating effect of angiotensin I type 1 receptor antagonist losartan and an-giotensin converting enzyme inhibitor captopril on aortic atherosclerosis in rabbits. Methods: Thirty-one male New Zealand rabbits were randomly divided into 5 groups:control group,high cholesterol diet group,losartan group, captopril group and combined drug administration groupdosartan+captopril). The animals were killed after 16 weeks and the serum total cholesterol ,triglyceride, high and low density cholesterol .atherosclertic ratio,endothelin,NO,plaque area percentage,aortic cholesterol content and vascular smooth muscle cell (VSMC) apoptosis were determined. Results:The plaque area percentage,aortic cholesterol contents and endothelin levels of 3 drug treatment groups were significantly lower than that of high cholesterol group,NO contents and VSMC apoptosis were significantly higher. Conclusion:Losartan and captopril can attenuate aortic atherosclerosis induced by high cholesterol diet .combined administration of the 2 drugs at low doses are more effective. The mechanism may be related to the protection of endothelial function and the effect on apoptosis of VSMC.