Miyamoto T, Ohizumi Y, Washio H, Yasumoto Y
Pflugers Arch. 1984 Apr;400(4):439-41. doi: 10.1007/BF00587546.
The effect of maitotoxin (MTX), the most potent marine toxin as yet known, was studied using the skeletal muscle of the larval meal worm, Tenebrio molitor. In normal saline, Tenebrio muscles responded with the spike to direct stimulation. In the saline containing tetraethylammonium (TEA) the all-or-none action potential which had characteristic plateau was elicited by membrane depolarization. When MTX (5 X 10(-9) to 10(-8) g/ml) in the TEA saline was added, the plateau of action potential was prolonged more than in the saline containing TEA alone. Furthermore, MTX lowered the threshold, so that action potentials were readily evoked in the saline containing MTX. In either case, effects, of MTX were antagonized by Co2+. These results suggest that MTX activates the voltage-dependent Ca2+ channels in the insect muscle.
利用黄粉虫幼虫（黄粉虫）的骨骼肌研究了已知最强效的海洋毒素——刺尾鱼毒素（MTX）的作用。在生理盐水中，黄粉虫肌肉对直接刺激产生锋电位反应。在含有四乙铵（TEA）的盐水中，膜去极化可引发具有特征性平台期的全或无动作电位。当在含TEA的盐水中加入MTX（5×10⁻⁹至10⁻⁸克/毫升）时，动作电位的平台期比仅含TEA的盐水延长得更多。此外，MTX降低了阈值，因此在含MTX的盐水中很容易诱发动作电位。在这两种情况下，MTX的作用都被Co²⁺拮抗。这些结果表明，MTX激活了昆虫肌肉中的电压依赖性Ca²⁺通道。
