Interactions of aminopyridines with potassium channels of squid axon membranes.
Interactions of aminopyridines with potassium channels of squid axon membranes.
复制标题
氨基吡啶与鱿鱼轴突膜钾通道的相互作用。
DOI：
10.1016/s0006-3495(76)85663-9
复制
发表时间：
1976
影响因子：
3.4
通讯作者：
Toshio Narahashi
中科院分区：
文献类型：
--
作者：
J. Yeh;G. Oxford;C. Wu;Toshio Narahashi
用电压钳和内灌注技术研究了氨基吡啶类药物对鱿鱼巨轴突膜离子电导的影响。4-氨基吡啶（4-AP）减少钾电流，但对瞬时钠电流没有影响。4-AP对钾通道的阻断作用随着（a）强去极化至正膜电位，（B）增加给定去极化步骤的持续时间，和（c）增加步骤去极化的频率而显著减少。高钾浓度的实验表明，4-AP的效果是独立的钾离子运动的方向。3-氨基吡啶和2-氨基吡啶与4-AP除了效力之外没有区别。它的结论是，氨基嘧啶可以被用来作为工具，以阻止钾电导在可兴奋的膜，但只有在某些特定的电压和频率的限制。
The effects of aminopyridines on ionic conductances of the squid giant axon membrane were examined using voltage clamp and internal perfusion techniques. 4-Aminopyridine (4-AP) reduced potassium currents, but had no effect upon transient sodium currents. The block of potassium channels by 4-AP was substantially less with (a) strong depolarization to positive membrane potentials, (b) increasing the duration of a given depolarizing step, and (c) increasing the frequency of step depolarizations. Experiments with high external potassium concentrations revealed that the effect of 4-AP was independent of the direction of potassium ion movement. Both 3- and 2-aminopyridine were indistinguishable from 4-AP except in potency. It is concluded that aminopyrimidines may be used as tools to block the potassium conductance in excitable membranes, but only within certain specific voltage and frequency limits.