Failure of nifedipine to reduce atherogenesis in cholesterol-fed rabbits.

The purpose of this study was to determine if therapeutic dosages of nifedipine, a drug that reduces intracellular calcium concentrations, suppresses atherogenesis in normotensive, cholesterol-fed rabbits. Control groups were fed either normal chow (Group I), or normal chow supplemented with 0.10 and 0.25% cholesterol (wt/wt) (Group II). Group III animals were fed the same diets as Group II animals and received nifedipine (0.625 and 1.250 mg/kg/d). During the course of the study (3 months) no systematic quantitative difference (P greater than 0.05) was observed between Groups II and III with regard to mean arterial blood pressure, serum cholesterol, serum electrolytes (sodium and potassium), plasma renin activity, or serum lipoprotein classes. At necropsy, there likewise was no difference in affected aortic surface area, aortic cholesterol content, or renal renin content. We conclude that nifedipine, at human therapeutic dosages, has no effect on either atherogenesis or the renin-angiotensin system in normotensive rabbits fed a moderately cholesterol-rich diet.