title: Comparative effects of FR 34235, a new slow channel calcium blocker, and nifedipine on hemodynamics and myocardial oxygen consumption in the anesthetized dog.
abstract: Five doses of two dihydropyridine calcium antagonists, FR 34235 and nifedipine, were given intravenously to anesthetized dogs to determine effects on hemodynamics and myocardial oxygen balance. Both agents produced dose-related decreases in mean arterial blood pressure and tension time index with little effect on heart rate, dP/dt or myocardial contractile force except at high doses where small decreases were observed. Coronary blood flow increased markedly in the presence of both agents with a maximum increase observed at doses of 10 and 30 micrograms/kg for FR 34235 and nifedipine, respectively. Both compounds decreased myocardial oxygen extraction at all doses and reduced myocardial oxygen consumption at higher doses. These results indicate that FR 34235, a new slow channel calcium blocker, is a potent coronary vasodilator. In addition, this compound possesses oxygen-sparing activity at higher doses.
mesh_terms: D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects; D004285:Dogs; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*
chemical_list: D002121:Calcium Channel Blockers; C035100:nilvadipine; D009543:Nifedipine