ANTIATHEROGENIC EFFECT OF CAPTOPRIL IN THE WATANABE HERITABLE HYPERLIPIDEMIC RABBIT

The effects of 9 months of orally administered captopril (25-50 mg/kg body wt/day) on aortic atherosclerosis was examined in normotensive Watanabe heritable hyperlipidemic rabbits. Captopril caused a significant decrease in aortic atherosclerosis. Total aortic surface involvement by lesions was reduced from 48±3.6% in control Watanabe rabbits to 30±3.9% with captopril treatment (p<0.01). Most of the decrease could be accounted for by a marked reduction in atherosclerosis of descending thoracic aortas from 49±5.2% to 15±3.9% in control and captopril-related groups, respectively (p<0.001). Significant decrease in cholesterol content of descending thoracic aorta was also observed in captopril-treated rabbits. Microscopic examination of the arterial lesions in captopril-treated animals suggested a relative decrease in cellularity and increase in extracellular matrix as compared with untreated animals. These studies indicate that captopril has a potent antiatherosclerotic action in the Watanabe heritable hyperlipidemic rabbit.