Calcium antagonistic drugs. Mechanism of action.

摘要: Calcium antagonists represent a new class of drugs, which were suggested to act by selective inhibition Ca2+ influx through cell membranes. We studied the mechanism action three calcium antagonists, diltiazem, nifedipine, and verapamil, investigating effect on 45Ca uptake efflux in rat heart aorta rabbit vessels. The La3+-resistant was not decreased nifedipine or verapamil either vessels increased diltiazem from mesenteric vein rabbit, originating presumably intracellular membrane-boudn fractions, enhanced nifedipine. These effects observed with drug concentrations inhibiting contractions isolated atria spontaneous norepinephrine-, potassium-, barium-induced portal rats. Thus, our results suggest that antagonistic drugs other mechanisms than transmembranous Ca flux, probably release binding pools. relatively greater norepinephrine- K+-induced abolition inotropic norepinephrine atrium exposed 0-Ca Krebs solution for short period are suggesting an these drugs.