Effect of captopril on membrane currents of ventricular myocytes.

Using whole-cell patch-clamp technique, the present study examined the effects of captopril on membrane currents of ventricular myocytes. The results were as follow: when the concentration of captopril was 6 x 10(-4)mol, the fast inward sodium current and slow inward calcium current were all decreased significantly (P < 0.05). Besides, when the concentration exceeds 10(-3)mol, the delayed rectifier potassium current was increased (P < 0.05) as well. But if the experimental concentration was under 6 x 10(-4)mol, these three kinds of currents was not affected. These findings suggested that captopril has no direct antiarrhythmic effect at the average therapeutic serum level.