Effect of nisoldipine on large coronary arteries in situ: inhibition of vasoconstriction induced by vasopressin.
The effects of nisoldipine on myocardial performance and large coronary artery diameter, resistance and cross-sectional area were studied in rabbit hearts in situ. Changes in mean internal diameter of coronary artery segments were visualized using color arteriography; changes were computer-calculated. Nisoldipine had a direct dilatory effect on large coronary arteries in situ and it attenuated the vasoconstriction induced by vasopressin. It shifted the dose-response curve of vasopressin to the right in a noncompetitive manner. Nisoldipine reduced the effect of vasopressin on maximum left ventricular dP/dt, mean aortic pressure, left ventricular end-systolic pressure and heart rate. The results demonstrate that nisoldipine is an effective dilator of large epicardial coronary arteries in situ and inhibits the vasoconstriction induced by vasopressin.
Saito
T
T
Huntington Medical Research Institutes, Huntington Memorial Hospital, Pasadena, Calif.
Saeed
M
M
Bing
R J
RJ
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015737:Nisoldipine; D011817:Rabbits; D014661:Vasoconstriction / Q000187:drug effects*; D014667:Vasopressins / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D014667:Vasopressins; D015737:Nisoldipine; D009543:Nifedipine