Diltiazem actions on smooth muscle cells of the porcine coronary artery and on neuromuscular junctions of the guinea-pig vas deferens

Abstract 1. 1. Diltiazem suppressed the mechanical threshold required for contraction and decreased the amplitude of contraction evoked by excess [K] 0 , electrical depolarization and acetylcholine without any change in the membrane property of the porcine coronary artery. 2. 2. Diltiazem suppressed the amplitude of excitatory junction potential and facilitation process produced by repetitive stimulation in hypogastric nerve-vas deferens preparations. 3. 3. Vasodilating actions of diltiazem might be due to suppressions of Ca-mobilization in the vascular muscle and also in part, of noradrenaline release from the nerve terminal.