Kotake H, Hisatome I, Igawa O, Mashiba H
Eur J Pharmacol. 1985 Aug 27;114(3):291-6. doi: 10.1016/0014-2999(85)90372-3.
The electrophysiological effect of dilazep (1 X 10(-7) -3 X 10(-6) M), a coronary vasodilator, was examined on rabbit sinoatrial node cells using glass microelectrode and double microelectrode voltage clamp methods. Dilazep exerted a negative chronotropic effect and decreased the maximum rate of depolarization of the upstroke of the action potential and the amplitude of the action potential. The action potential duration at half-amplitude was prolonged after the drug perfusion. The voltage clamp experiment showed that dilazep reduced the slow inward current (Isi), the potassium outward current (IK), and the hyperpolarization-activated current (Ih). The recovery time constant of Isi was also prolonged. In conclusion, it is indicated that dilazep has no specific effect on the current system, but the drug depresses specifically the electrical activity of sinoatrial node cells.
采用玻璃微电极和双微电极电压钳方法，研究了冠状动脉扩张剂地拉卓（1×10⁻⁷ - 3×10⁻⁶ M）对兔窦房结细胞的电生理效应。地拉卓产生负性变时作用，降低动作电位上升支的最大去极化速率和动作电位幅度。药物灌注后，动作电位半幅持续时间延长。电压钳实验表明，地拉卓降低慢内向电流（Isi）、钾外向电流（IK）和超极化激活电流（Ih）。Isi的恢复时间常数也延长。总之，表明地拉卓对电流系统无特异性作用，但该药物特异性抑制窦房结细胞的电活动。
