破伤风毒素：对培养的神经母细胞瘤N1E-115细胞动作电位的钙成分而非钠成分具有快速且选择性的阻断作用。

Tetanus toxin: a rapid and selective blockade of the calcium, but not sodium, component of action potentials in cultured neuroblastoma N1E-115 cells.

作者信息

Higashida H, Sugimoto N, Ozutsumi K, Miki N, Matsuda M

出版信息

Brain Res. 1983 Nov 21;279(1-2):363-8. doi: 10.1016/0006-8993(83)90211-1.

Abstract

The slow action potential of mouse neuroblastoma N1E-115 cells, which was elicited in Na-free medium and whose amplitude was directly dependent on extracellular Ca concentrations, was blocked by tetanus toxin (TNTX) without change in resting membrane potential and resistance. The average value of action potential overshoot (peak potential level of spikes) in the absence and presence of TNTX was -1 and -11 mV, respectively. The concentration of TNTX required for 50% inhibition of Ca-dependent spikes (IC50) was about 65 ng/ml. The amplitude of spikes was decreased within 10-20 min after adding TNTX. The inhibition of Ca-dependent spikes was mimicked by 10 mM CoCl2 and MnCl2, but not by the boiled or neutralized toxin. The results indicate that TNTX inhibited electrogenesis of Ca, but not Na, components of action potentials of the neuroblastoma cells.

摘要

在无钠培养基中引发的小鼠神经母细胞瘤N1E-115细胞的慢动作电位，其幅度直接依赖于细胞外钙浓度，被破伤风毒素（TNTX）阻断，静息膜电位和电阻无变化。在不存在和存在TNTX的情况下，动作电位超射（尖峰的峰值电位水平）的平均值分别为-1和-11 mV。50%抑制钙依赖性尖峰（IC50）所需的TNTX浓度约为65 ng/ml。添加TNTX后10-20分钟内尖峰幅度降低。10 mM CoCl2和MnCl2可模拟对钙依赖性尖峰的抑制，但煮沸或中和的毒素则不能。结果表明，TNTX抑制了神经母细胞瘤细胞动作电位中钙成分的电发生，而不是钠成分。