TETRODOTOXIN BLOCKAGE OF SODIUM CONDUCTANCE INCREASE IN LOBSTER GIANT AXONS.
TETRODOTOXIN BLOCKAGE OF SODIUM CONDUCTANCE INCREASE IN LOBSTER GIANT AXONS.
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DOI：
10.1085/jgp.47.5.965
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发表时间：
1964-05
期刊：
影响因子：
--
通讯作者：
SCOTT WR
中科院分区：
文献类型：
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作者：
NARAHASHI T;MOORE JW;SCOTT WR
以往的研究表明，河豚毒素是一种来自河豚鱼的毒素，它通过选择性地抑制钠转运机制来阻断神经和肌肉的传导。为了验证这一假说，我们用蔗糖隙电压钳技术观察了河豚毒素处理的龙虾巨轴突的钠电流和钾电流。浓度为1 x 10-7至5 x 10-9 gm/ml的河豚毒素可阻断动作电位，但对静息电位无影响。用正常培养基冲洗时可能会部分或完全恢复。当河豚毒素阻断动作电位后，去极化时通常发生的钠电导增加被非常有效地抑制，而钾电导的延迟增加没有变化。它的结论是，河豚毒素，在非常低的浓度，通过其选择性抑制的钠携带机制，同时保持完整的钾携带机制阻断动作电位的生产。
Previous studies suggested that tetrodotoxin, a poison from the puffer fish, blocks conduction of nerve and muscle through its rather selective inhibition of the sodium-carrying mechanism. In order to verify this hypothesis, observations have been made of sodium and potassium currents in the lobster giant axons treated with tetrodotoxin by means of the sucrose-gap voltage-clamp technique. Tetrodotoxin at concentrations of 1 x 10-7 to 5 x 10-9 gm/ml blocked the action potential but had no effect on the resting potential. Partial or complete recovery might have occurred on washing with normal medium. The increase in sodium conductance normally occurring upon depolarization was very effectively suppressed when the action potential was blocked after tetrodotoxin, while the delayed increase in potassium conductance underwent no change. It is concluded that tetrodotoxin, at very low concentrations, blocks the action potential production through its selective inhibition of the sodium-carrying mechanism while keeping the potassium-carrying mechanism intact.