Moore J W, Blaustein M P, Anderson N C, Narahashi T
J Gen Physiol. 1967 May;50(5):1401-11. doi: 10.1085/jgp.50.5.1401.
The blockage of nerve activity by tetrodotoxin is unusually potent and specific. Our experiments were designed to distinguish whether its specificity of action was based on the identification of ions, the direction of cation flow, or differences in the early transient and late steady conductance pathways. Alkali cations were substituted for sodium in the sea water, bathing an "artificial node" in a voltage-clamped squid axon. When tetrodotoxin was added to the artificial sea waters at a concentration of 100 to 150 mM, it was found to always block the flow of cations through the early transient channel, both inward and outward, but it never blocked the flow of ions using the late steady pathway. We conclude that the selectivity of tetrodotoxin is based on some difference in these two channels.
河豚毒素对神经活动的阻断作用异常强大且具有特异性。我们设计了实验来区分其作用的特异性是基于对离子的识别、阳离子流动的方向，还是早期瞬态和晚期稳态电导途径的差异。在电压钳制的枪乌贼轴突中，用碱金属阳离子替代海水中的钠来浸泡“人工节点”。当在人工海水中加入浓度为100至150 mM的河豚毒素时，发现它总是会阻断阳离子通过早期瞬态通道的流动，无论是内向还是外向，但它从未阻断使用晚期稳态途径的离子流动。我们得出结论，河豚毒素的选择性是基于这两种通道的某些差异。
