Effects of a new calcium entry blocking agent, KB-944, on the membrane potential and currents of mammalian ventricular muscle cells.
KB-944 (10(-5)-10(-4) M) decreased the action potential duration measured at 30% repolarization and hyperpolarized the resting membrane potential in ventricular trabeculae of the dog heart. In single ventricular cells of the guinea-pig heart, KB-944 (10(-4) M) abolished the slow inward current and produced an outward shift of the late current measured at the end of 200 msec clamp pulse. From these results it appears that KB-944 selectively blocks the slow inward current and may increase the background potassium conductance.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D052160:Benzothiazoles; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004285:Dogs; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D013844:Thiazoles / Q000494:pharmacology*
D052160:Benzothiazoles; D002121:Calcium Channel Blockers; D013844:Thiazoles; C035950:fosfedil