碘化N-正丁基氟哌啶醇对大鼠心室肌细胞膜钾通道的影响

目的研究碘化N-正丁基氟哌啶醇(F2)对大鼠心室肌细胞膜瞬时外向钾通道的影响。方法采用酶急性消化法分离得到单个大鼠心室肌细胞,应用膜片钳全细胞记录技术观察F2对大鼠心室肌细胞膜瞬时外向钾电流(Ito)的影响。结果F2可剂量依赖地抑制Ito,IC50为0.28mmol·L-1。F2可使Ito的稳态失活曲线左移,半量膜电位Vmid变负,斜率因子S变大;但对激活曲线几乎无影响;对Ito灭活后再复活时程无影响。结论F2对心室肌膜Ito具有抑制作用。

Effects of N-n-butyl haloperidol iodide on transient outward potassium channels in rat ventricular myocytes

Aim To study effects of N-n-butyl haloperidol iodide on transient outward potassium channels in rat ventricular myocytes. Methods Single ventricular myocytes were obtained by enzymatic dissociation. The effect of F2 on transient outward potassium current (Ito) was recorded by the whole-cell patch-clamp recording technique. Results F2 caused a concentration-dependent inhibition of Ito with a calculated IC50 of 0.28 mmol·L-1. F2 caused a shift of the steady-state inactivation curves of Ito to negative potential with the half-inactivation voltage (Vmid) changing from (-17.45 ±6.14) mV to (-26.32±9.71) mV(P<0.05)and the slope factor (S) from (3.52±1.72) mV to (10.27±6.32) mV(P<0.05). On the contrary, F2 produced only slight effects on the steady-state activation curve of Ito. The parameter τ of recovery curve of Ito from inactivation was also little affected by F2. Conclusion F2 can inhibit transient outward potassium channels slightly in rat ventricular myocytes.