Action potential and ionic currents of myocardial fibers in the mollusc Spisula sachalinensis

Abstract

1. 1. A double-sucrose gap current-clamp and voltage-clamp method was used to investigate the action potentials and ionic membrane currents of ventricular fibers in the mollusc Spisula sachalinensis. 2. 2. The results obtained suggest an action potential generated by an inward voltage-dependent calcium channel current and an outward voltage-dependent transient potassium current. 3. 3. The neuromediators serotonin and acetylcholine did not influence action potential or ionic currents. The regulation of molluscan heart tension by these mediators is not related to the membrane potential-dependent ionic channels.