[Inhibition of the sodium inactivation of the nodal membrane by anemonia sulcata toxin II].

A neurotoxin (ATX-II) extracted from the tentacles of Anemonia sulcata has been found to interact with the sodium channel of the nodal membrane in myelinated nerve fibres from Rana esculenta. If externally applied at low concentration (Kd = 20 muM), it reduces considerably the rate of inactivation of the sodium conductance without affecting the activation. At such concentrations, the potassium conductance is not affected. If internally applied ATX-II does not affect the membrane conductance.