Blockage of Sodium Conductance Increase in Lobster Giant Axon by Tarichatoxin (Tetrodotoxin)

摘要: Tarichatoxin, isolated from California newt eggs, has been found to selectively block the increase of sodium conductance associated with excitation in lobster giant axons at nanomolar concentrations. This resulted a reduction amplitude rather than change its temporal characteristics. The normal potassium depolarization is not altered. A high concentration calcium applied concomitantly toxin significantly improves reversibility blocking. recently identified as chemically identical tetrodotoxin puffer fish. Toxins two sources are equally effective and shown have an action which distinctly different that procaine.