Mozhaeva G N, Naumov A P, Khodorov B I
Neirofiziologiia. 1984;16(1):18-26.
Currents through batrachotoxin (BTX)-modified sodium channels in frog myelinated nerve were measured under voltage-clamp conditions. Nonlinearity of "instantaneous" current-voltage relations was taken into account when determining steady-state parameters of channel activation. BTX induces the shift of voltage dependence of channel activation towards more negative potentials by 67 mV, without changes in its steepness. Current kinetics and effect of preceding depolarization on current size suggest that BTX-modified channels are capable for partial inactivation. High level of steady-state conductance of BTX-modified channels can be explained by suggestion that open state of the channel is energetically more profitable than inactivated one. It is concluded that effect of BTX on inactivation is different in principle from that of pronase and protein reagents.
在电压钳制条件下，测量了蛙有髓神经中经蟾毒素（BTX）修饰的钠通道的电流。在确定通道激活的稳态参数时，考虑了“瞬时”电流 - 电压关系的非线性。BTX使通道激活的电压依赖性向更负的电位偏移67 mV，而其斜率不变。电流动力学以及先前去极化对电流大小的影响表明，BTX修饰的通道能够进行部分失活。BTX修饰通道的高稳态电导水平可以通过以下观点来解释：通道的开放状态在能量上比失活状态更有利。得出的结论是，BTX对失活的影响在原则上与链霉蛋白酶和蛋白质试剂的影响不同。
