Coronary dilator effect of MCI-176, a new calcium channel blocker, in dogs.

Effects of MCI-176, 2-(2,5-dimethoxyphenylmethyl)-3-(2-dimethylaminoethyl)-6-isopropox y-4 (3H)-quinazolinone hydrochloride, on coronary and aortic blood flows, mean blood pressure and heart rate were investigated in comparison with those of diltiazem in anesthetized dogs. MCI-176, like diltiazem, dose-dependently increased coronary and aortic blood flows and decreased mean blood pressure. In producing these effect MCI-176 was slightly but significantly more potent than diltiazem. Heart rate tended to increase with MCI-176, whereas it tended to decrease with diltiazem.