苄普地尔抑制大鼠海马CA1区锥体细胞钠电流(英文)

Bepridil inhibition of sodium current in rat hippocampal CA1 neurons

目的:研究苄普地尔对大鼠海马CA1区锥体细胞钠电流的影响。方法:膜片箝全细胞记录技术。结果:苄普地尔显著降低大鼠海马CA1区锥体细胞钠电流,作用呈时间及浓度依赖关系。苄普地尔10μmol·L^(-1)的半阻断时间约为10min。IC_(50)为2.6(2.3-2.9)μmol·L^(-1)。苄普地尔10μmol·L^(-1)右移最大电流的激活电位10mV,左移半失活膜电位18mV,表明其电压依赖地影响钠通道的激活和失活过程。结论:苄普地尔阻断大鼠海马CA1区锥体细胞钠电流,可能是其抗脑缺血机制之一。

AIM: To study the effects of bepridil on sodium current in rat 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 -89mV 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.