Bepridil inhibition of sodium current in rat hippocampal CA1 neurons

AIM: To study the effects of bepridil on sodium current in mt hippocampal neurons. METHODS: All experiments were performed on acutely isolated hippocampal pyramidal neurons by means of whole-cell patch-clamp techniques. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent sodium currents. RESULTS: Bepridil reduced the amplitudes of sodium current in time- and concentration-dependent manners. The half-blocking time was about 10 min in bepridil 10 μmol · L^{- 1}, and IC₅₀ was 2.6 (2.3 - 2.9) μmol · L^-1. Bepridil 10 μmol · L^-1 shifted the maximal activation of sodium current from - 50 mV to - 40 mV, and the characteristic voltage of inactivation from - 71 mV to -89 mV without changing the slope factor. CONCLUSION: Bepridil blocked voltage-dependent sodium current of hippocampal CA1 neurons and might have therapeutic actions for ischemia-induced brain damage.