Calcium antagonists suppress atherogenesis in aorta but not in the intramural coronary arteries of cholesterol-fed rabbits.

We tested the effects of the calcium antagonists lanthanum, diltiazem, and flunarizine on the development of atherosclerosis in rabbits fed a 2% cholesterol diet. The drugs were given orally and were well tolerated. In the cholesterol control animals, 52.2% of the thoracic aortic intimal surface was Sudan IV positive. This was reduced by 37% (p less than 0.05) with lanthanum, 37% (p less than 0.05) with diltiazem, and 34% (p less than or equal to 0.06) with flunarizine. In all cholesterol-fed animals, the intramural, but not subepicardial, coronary arteries were severely diseased. The extent and distribution of this disease were not altered by the various drug interventions. Thus, the calcium antagonists lanthanum, diltiazem, and flunarizine suppress atherogenesis of the rabbit aorta but have no effect on the extent or distribution of atherosclerosis in the intramural coronary arteries.