Hille B
J Gen Physiol. 1968 Feb;51(2):199-219. doi: 10.1085/jgp.51.2.199.
Voltage clamp measurements on myelinated nerve fibers show that tetrodotoxin, saxitoxin, and DDT specifically affect the sodium channels of the membrane. Tetrodotoxin and saxitoxin render the sodium channels impermeable to Na ions and to Li ions and probably prevent the opening of individual sodium channels when one toxin molecule binds to a channel. The apparent dissociation constant of the inhibitory complex is about 1 nM for the cationic forms of both toxins. The zwitter ionic forms are much less potent. On the other hand, DDT causes a fraction of the sodium channels that open during a depolarization to remain open for a longer time than is normal. The effect cannot be described as a specific change in sodium inactivation or as a specific change in sodium activation, for both processes continue to govern the opening of the sodium channels and neither process is able to close the channels. The effects of DDT are very similar to those of veratrine.
对有髓神经纤维进行的电压钳测量表明，河豚毒素、石房蛤毒素和滴滴涕会特异性地影响细胞膜的钠通道。河豚毒素和石房蛤毒素使钠通道对钠离子和锂离子不可通透，并且当一个毒素分子与一个通道结合时，可能会阻止单个钠通道的开放。两种毒素的阳离子形式的抑制复合物的表观解离常数约为1 nM。两性离子形式的效力要低得多。另一方面，滴滴涕会使一部分在去极化过程中打开的钠通道比正常情况下保持开放的时间更长。这种效应不能被描述为钠失活的特异性变化或钠激活的特异性变化，因为这两个过程继续控制着钠通道的开放，且没有一个过程能够关闭通道。滴滴涕的作用与藜芦碱的作用非常相似。
