Effects of intravenously and orally administered cinpropazide on the coronary circulation in unanesthetized and unrestrained dogs.

Cardiovascular effects of cinpropazide (1-(3',4',5'-trimethoxycinnamoyl)-4-(N-isopropylaminocarbonylme th yl)-piperazine maleate) administered i.v. and p.o. were investigated in unanesthetized and unrestrained dogs by means of radiotelemetering system with preceding chronic implantations of an aortic and a venous catheter, Doppler flow probe around circumflex branch in the left coronary artery and subcutaneous ECG electrodes. Intravenous administration of cinpropazide indicated that the drug was much less potent in coronary vasodilating property than newly introduced group of coronary vasodilators. However, the oral administration of this agent efficiently exhibited a remarkable increase in the coronary blood flow, suggesting that this agent has an extremely high bioavailability. It is concluded that cinpropazide is a coronary vasodilator to succeed nifedipine and nicorandil exhibiting an actual increase of coronary blood flow by oral administration in the dog.