Effects of divalent cations on the inhibitory potentials in the duodenal smooth muscle cells of the guinea-pig.

摘要: The effects of divalent cations and some Ca2+ antagonists on the non-adrenergic inhibitory potential (i.p.) in duodenal smooth muscle cells guinea-pig were investigated intracellularly. membrane was a function external (0.25-7.5mM) Mg2+ (1.2-24mM) concentrations. latency time to peak i.p. prolonged by low excess Mg2+. amplitude rate hyperpolarization reduced Mn2+ (5-10mM) similar those except for small depolarization. evoked Ca2+-free solution considerably restored addition Ba2+ (1.25mM) Sr2+ (2mM). actions inhibited verapamil (10-4g/ml). Verapamil (2×10-5-2×10-4g/ml) gentamicin (10-3g/ml) but not gentamicin. In nifedipine (10-4g/ml), two-peaked single stimulus. This that paired pulse normal solution. results obtained suggest released substance requires which moves into neurons through conductance pathway.