Mozhaeva G N, Naumov A P, Khodorov B I
Neirofiziologiia. 1983;15(5):485-94.
Currents through batrachotoxin-modified sodium channels in frog myelinated fibres were measured under voltage-clamp conditions. Reversal potential (Erev) of steady-state currents is shown to be about 5 mV less positive than Erev of initial (peak) currents. Control experiments with procaine and tetrodotoxin in external solutions showed that this shift of Erev during depolarizing pulse cannot be accounted for by the presence of unmodified sodium channels, unblocked potassium channels, nonlinearity of the leakage or any changes in transmembrane gradients of current-carrying cations. "Instantaneous" current measurements showed that Erev becomes less positive as amplitude and duration of preliminary depolarization increase. The results obtained are consistent with assumption that sodium-potassium selectivity of the batrachotoxin-modified channels depends on potential.
在电压钳制条件下测量了蛙有髓神经纤维中经蟾毒素修饰的钠通道的电流。稳态电流的反转电位（Erev）比初始（峰值）电流的Erev正性约小5 mV。外部溶液中使用普鲁卡因和河豚毒素的对照实验表明，去极化脉冲期间Erev的这种偏移不能用未修饰的钠通道、未阻断的钾通道、泄漏的非线性或载流阳离子跨膜梯度的任何变化来解释。“瞬时”电流测量表明，随着预去极化的幅度和持续时间增加，Erev的正性降低。所获得的结果与蟾毒素修饰通道的钠钾选择性取决于电位的假设一致。
