Yellen G
J Gen Physiol. 1984 Aug;84(2):187-99. doi: 10.1085/jgp.84.2.187.
The flickery block of single Ca2+-activated K+ channels that is produced by internally applied Na+ can be relieved by millimolar concentrations of external K+. This effect of K+ on the kinetics of Na+ block was studied by the method of amplitude distribution analysis described in the companion paper (Yellen, G., 1984b, J. Gen. Physiol., 84:157-186). It appears that K+ relieves block by increasing the exit rate of the blocking ion from the channel, not by competitively slowing its entrance rate. This suggests that a K ion that enters the channel from the outside can expel the blocking Na ion, which entered the channel from the inside. Cs+, which cannot carry current through the channel, and Rb+, which carries a reduced current through the channel, are just as effective as K+ in relieving the block by internal Na+. The kinetics of block by internal nonyltriethylammonium (C9) are unaffected by the presence of these ions in the external bathing solution.
由内部施加的Na⁺产生的单个Ca²⁺激活K⁺通道的闪烁阻断可被毫摩尔浓度的外部K⁺解除。通过配套论文（耶伦，G.，1984b，《普通生理学杂志》，84:157 - 186）中描述的幅度分布分析方法，研究了K⁺对Na⁺阻断动力学的这种影响。似乎K⁺通过增加阻断离子从通道的退出速率来解除阻断，而不是通过竞争性地减慢其进入速率。这表明从外部进入通道的K离子可以排出从内部进入通道的阻断Na离子。不能通过通道传导电流的Cs⁺以及通过通道传导电流减少的Rb⁺，在解除内部Na⁺的阻断方面与K⁺同样有效。外部浴液中这些离子的存在不影响内部壬基三乙铵（C9）的阻断动力学。
