Hemodynamic effects of calcium antagonists with high or low vascular selectivity.
Infusion of felodipine and verapamil in increasing doses to anesthetized spontaneously hypertensive rats induced a progressive fall in arterial blood pressure (BP). To estimate the cardiac action of the different drugs, we also measured changes in cardiac output (CO) and velocity of flow (dF/dT) by a Doppler flow probe placed on the ascending aorta. Infusion of verapamil induced a parallel decrease in mean arterial BP, CO, and cardiac inotropy (as estimated by max. dF/dT). In contrast, upon felodipine administration, the decrease in arterial BP was accompanied by an initial small rise in dF/dT. A decrease in dF/dT was observed only after high doses of felodipine, which caused pronounced levels of hypotension.
Hässle Cardiovascular Research Laboratories, Mölndal, Sweden.
P
P
Thorén
M
M
Sjölander
M
M
Nordlander
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects; D015736:Felodipine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D014655:Vascular Resistance / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D014700:Verapamil; D015736:Felodipine