Effect of cobalt on electrical and mechanical responses to exogenous noradrenaline and to field stimulations in the guinea-pig vas deferens.

Co2+ suppressed the mechanical responses evoked by field stimulations and by application of noradrenaline (NA) in the smooth muscle of guinea-pig vas deferens. However, the membrane excitation and force development evoked by depolarizing currents were not much affected in the Co2+ treatment. It is proposed that Co2+ suppresses NA induced contraction by inhibiting the development of the membrane depolarization.