[The effect of divalent cations on the kinetics of the activation and blockade of the nicotinic cholinoreceptor ion channel in rat skeletal muscle].

The influence of alkaline earth metal ions calcium and magnesium on the conductance and on the kinetics of activation and atropine-induced blockade of nicotinic cholinoreceptor ion channels in cultured rat skeletal muscle were studied using patch-clamp technique. In physiological concentrations these cations influence both conductance and kinetics of blockade, but have no significant effect on the kinetics parameters of activation. The data suggest that physiological cations modulate the generation of postsynaptic potentials in the normal condition as well as in the presence of blocking drugs.