Simioni L R, Corrado A P, Jurkiewicz A
Gen Pharmacol. 1976 Aug;7(2-3):127-32. doi: 10.1016/0306-3623(76)90048-3.
McN-A-343 (McN), a non nicotinic ganglionic stimulant, induced slow contractile responses of the toad rectus abdominis. A relaxation was also observed when large doses were added in the presence of a contraction caused by acetylcholine (Ach). The relaxation induced by McN could not be overcome by increasing Ach concentration. Bell-shaped log dose-response curves were obtained for McN. d-Tubocurarine caused an unusual change on these curves, suggesting an indirect action of the agonist. This possibility was corroborated by the fact that hemicholinium, procaine, and cold storage of the muscle caused a marked decrease of the organ sensitivity to McN but not to ACh.
McN-A-343（McN）是一种非烟碱型神经节兴奋剂，可诱发蟾蜍腹直肌的缓慢收缩反应。当在乙酰胆碱（Ach）引起的收缩状态下加入大剂量McN时，也可观察到松弛现象。McN诱导的松弛不能通过增加Ach浓度来克服。McN呈现钟形对数剂量反应曲线。d-筒箭毒碱使这些曲线发生异常变化，提示该激动剂存在间接作用。肌肉使用半胱氨酸、普鲁卡因以及冷藏后对McN的器官敏感性显著降低，但对ACh的敏感性未降低，这一事实证实了这种可能性。
