Does nifedipine suppress atherogenesis in WHHL rabbits?

The effects of the calcium antagonist, nifedipine, on atherogenesis were investigated in WHHL rabbits, a unique animal model for human familial hypercholesterolemia. Nifedipine, in a daily dose of 40 mg, was fed orally to 9 rabbits over a period of 26 weeks, resulting in serum concentrations of between 740 and 1370 ng/ml. Rabbits were killed at an age of 40 weeks and atherosclerotic plaque formation in various aortic segments was quantified. Atherosclerosis was most pronounced in the aortic arch and the thoracic aorta, plaques covering, respectively, 59 +/- 17% and 17 +/- 9% of total vessel area. These results are similar to those observed in a control group, which received the same diet and no nifedipine and displayed lesions on 62 +/- 19% and 21 +/- 13% of total area of aortic arch and thoracic aorta, respectively. Although variations in plaque area between WHHL rabbits are large and thus preclude the observation of small effects, the efficacy of nifedipine as an anti-atherogenic agent in rabbits with hereditary hypercholesterolemia appears questionable.