Mack J E, Matthews J C
Res Commun Chem Pathol Pharmacol. 1986 Oct;54(1):13-21.
The neurotoxins veratridine and aconitine are best known for their abilities to open action potential sodium channels in neuronal and muscle cells. These neurotoxins were tested for their abilities to influence the binding of 3H-QNB in mouse forebrain employing a glass-fiber filtration assay. Veratridine and aconitine produced approximately 95% and 77% inhibition of muscarinic receptor specific 3H-QNB binding with IC50 values of 11 and 20 microM, respectively. Further analysis revealed that both veratridine and aconitine were competitive inhibitors of 3H-QNB binding. Tetrodotoxin, an antagonist of the actions of veratridine and aconitine on sodium channels, at 10 microM inhibited the binding of 3H-QNB by 9% in the presence of 10 microM veratridine while having no effect when used in combination with aconitine. These data indicate that there may be a relationship between muscarinic receptors and action potential sodium channels.
神经毒素藜芦定和乌头碱以其在神经元和肌肉细胞中打开动作电位钠通道的能力而最为人所知。采用玻璃纤维过滤分析法测试了这些神经毒素影响小鼠前脑3H-QNB结合的能力。藜芦定和乌头碱分别对毒蕈碱受体特异性3H-QNB结合产生约95%和77%的抑制，IC50值分别为11和20 microM。进一步分析表明，藜芦定和乌头碱都是3H-QNB结合的竞争性抑制剂。河豚毒素是藜芦定和乌头碱对钠通道作用的拮抗剂，在10 microM藜芦定存在的情况下，10 microM河豚毒素抑制3H-QNB结合9%，而与乌头碱联合使用时则无作用。这些数据表明毒蕈碱受体与动作电位钠通道之间可能存在关联。
