Goldberg D J, Cooper J R
J Neurobiol. 1975 Sep;6(5):435-52. doi: 10.1002/neu.480060502.
To assess the hypothesis that thiamine is directly involved in the permeability changes at the sodium channel during nerve conduction, the effects of thiamine antagonists on lobster giant axon resting and action potentials were determined. Thiamine antimetabolites, in millimolar concentrations, reversibly decreased the maximum rate of rise and amplitude of the action potential while increasing its duration. In particular, thiamine tert-butyl disulfide (TTBD) elicited the formation of pronounced shoulders during repolarization, lengthening the action potential by 2-50 times, depending on dose. Antimetabolites also depolarized the resting membrane, but this change was poorly reversible and may indicate a dual mechanism for antimetabolite action. An extract of the fern, Pteris aquilina, reversibly decreased the maximum rate of rise of the action potential and depolarized the resting potential. It also elevated and prolonged the action potential after-depolarization, sometimes causing repetitive activity. The strength of these actions was correlated with the antithiamine potency of the extract, and was diminished by addition of thiamine to the extract.
为了评估硫胺素在神经传导过程中直接参与钠通道通透性变化这一假说，研究了硫胺素拮抗剂对龙虾巨轴突静息电位和动作电位的影响。毫摩尔浓度的硫胺素抗代谢物可使动作电位的最大上升速率和幅度可逆性降低，同时延长其持续时间。特别是，硫胺素叔丁基二硫化物（TTBD）在复极化过程中引发明显的峰肩形成，根据剂量不同，动作电位延长2至50倍。抗代谢物还使静息膜去极化，但这种变化很难逆转，可能表明抗代谢物作用存在双重机制。蕨类植物鹰爪蕨的提取物可使动作电位的最大上升速率可逆性降低，并使静息电位去极化。它还增强并延长了动作电位后的去极化，有时会导致重复活动。这些作用的强度与提取物的抗硫胺素效力相关，并且通过向提取物中添加硫胺素而减弱。
