EŠects of Benidipine in a Rat Model of Experimental Angina

To compare the antianginal eŠects of 1,4-dihydropyridine-type calcium-channel blockers, we evaluated the eŠects of benidipine, amlodipine, nifedipine, and efonidipine on vasopressin-induced myocardial ischemia in rats, an experimental model of angina. Intravenous administration of benidipine (3 mg/kg), amlodipine (1000 mg/kg), and nifedipine (100 mg/kg) suppressed the vasopressin-induced S-wave depression, an index of myocardial ischemia. Efonidipine (100 mg/kg, i.v.) tended to inhibit the S-wave depression. At the antianginal dose of each drug, amlodipine, nifedipine, and efonidipine decreased blood pressure signiˆcantly, whereas benidipine had little eŠect on blood pressure at a dose of 3 mg/kg. These results indicate that benidipine, unlike the other 1,4-dihydropyridine-type calcium-channel blockers examined in this study, inhibits vasopressin-induced coronary vasospasm with fewer undesirable eŠects such as hypotension in rats, suggesting that benidipine may be useful in the treatment of angina pectoris.