[The effect of allapinine on the sodium currents of isolated trigeminal ganglion neurons and cardiomyocytes of rats].

Block of sodium currents by allapinine (diterpene alkaloid with strong antiarrhythmic properties) was investigated in isolated, voltage-clamped trigeminal neurons of a rat and single ventricular myocytes of a neonatal rat. Allapinine (in micromolar concentrations) produced a 70-90% decrease of the sodium current amplitude without any changes in voltage-dependent properties of INa in both neurons and cardiomyocytes. Allapinine also blocked the aconitine-modified sodium current. An increase of depolarization frequencies (0.5 to 5.0 Hz) produced no additional block of sodium currents in allapinine-bathed neurons and ventricular myocytes.