Nosaka S, Ohkawa T, Okihara K, Yoshikawa K
Department of Anesthesiology, Center for Adult Diseases, Osaka, Japan.
Biochim Biophys Acta. 1992 May 21;1106(2):325-34. doi: 10.1016/0005-2736(92)90013-c.
The effects of lidocaine, tetracaine, procaine and bupivacaine (less than 1000 microM) on the Chara corallina internodal cell were studied. These local anesthetics depolarized the membrane at rest, while they affected the rising phase and the peak level of action potential not appreciably. Instead, they prolonged the time course of the falling phase of action potential as slowly as the repolarization was imperfect, even after enough lapse beyond the refractory period. Consequently, an action potential appeared to enhance the degree of depolarization at rest. Such a depolarization with stimulus/excitation was named use-dependent depolarization, while the depolarization without excitation, the resting one. The order of the potency of the use-dependent depolarization almost coincided with that of the nerve-blocking potency. During depolarization the change in membrane conductance was not simple. However, the conductance-voltage (Gm-Vm) relationship curve in the presence of local anesthetic suggested that depolarization was due to, not only the decrease in the electrogenic H(+)-pump, but also the increase in the diffusion conductance.
研究了利多卡因、丁卡因、普鲁卡因和布比卡因（浓度小于1000微摩尔）对轮藻节间细胞的影响。这些局部麻醉药使静息膜电位去极化，而对动作电位的上升相和峰值影响不明显。相反，它们会随着复极化不完全而缓慢延长动作电位下降相的时间进程，即使在超过不应期足够长的时间之后也是如此。因此，动作电位似乎会增强静息时的去极化程度。这种由刺激/兴奋引起的去极化被称为使用依赖性去极化，而无兴奋时的去极化则称为静息去极化。使用依赖性去极化的效力顺序与神经阻滞效力顺序几乎一致。在去极化过程中，膜电导的变化并不简单。然而，局部麻醉药存在时的电导-电压（Gm-Vm）关系曲线表明，去极化不仅是由于生电H(+)-泵的减少，还由于扩散电导的增加。
