胺碘酮抑制缺血浦肯野纤维起搏离子流

Amiodarone Inhibits the Pacemaker Current in Ischemia - like Condition

目的观察正常及模拟“缺血”时胺碘酮对绵羊心室浦肯野纤维起搏离子流（Ｉｆ）的影响。方法双微电极电压钳制术，使膜电位过度极化以激活Ｉｆ。结果胺碘酮１×１０－５ｍｏｌ／Ｌ在正常台氏液中显著降低浦肯野纤维Ｉｆ幅值；模拟“缺血”也使Ｉｆ幅值降低，在此基础上，胺碘酮使Ｉｆ幅值进一步减小，加剧了“缺血”对Ｉｆ离子流的抑制作用。结论提示胺碘酮能抑制心肌缺血时心室正常自律性活动。

Objective To observe the effects of amiodarone on the normal ventricularpacemaker current if in normal Tyrode solution and ischemia - like condition. Methods Byusing double microelectrode voltage clamp technique, the ventricular normal pacemakercurrent if was activated and measured at different hyperpolarization membrane potentials.Results in normal Tyrode solution, the amplitude of if was significantly decreased byamiodarone 1 × 10-5mol/L in amount:'ischemia' decreased the amplitude of If, andamiodarone aggravated the inhibitory effect. Conclusion These results suggested thatamiodarone has an inhibitory effect on the normal pacemaker activity of the ventricle inischemic condition.