【摘要】 用细胞内记录方法检测２－氯－４－溴－α－甲基肉桂酸钠盐（ＳＣ１００１Ｎａ）和通道阻断剂四乙铵、氯化锰及河豚毒素对中华大蟾蜍离体缝匠肌动作电位和静息电位的影响。１０ｍｍｏｌ／Ｌ四乙铵及氯化锰对静息电位和动作电位幅度无影响，１μｍｏｌ／Ｌ河豚毒素完全阻断动作电位。２ｍｍｏｌ／ＬＳＣ１００１Ｎａ显著降低动作电位幅度并延长其持续时程（Ｐ＜０．０５），而对静息电位无影响，但其作用可逆。经四乙铵１０ｍｍｏｌ／Ｌ预处理后，２ｍｍｏｌ／ＬＳＣ１００１Ｎａ仍能延长动作电位持续时程，同时降低其幅度，而１０ｍｍｏ１／ＬＳＣ１００１Ｎａ完全阻断动作电泣，并使静息电位去极化（Ｐ＜０．０５）。且药物效应为不可逆。本研究结果提示：ＳＣ１００１Ｎａ可能是一种新型钠通道阻断剂。更多还原

【Abstract】 he effcts of 2-Chloro-4-Bromo-α-Methylcinnamic acid sodium（SC1001 Na）and somechannel antagonists on the action potential（AP） andthe resting potential（RP） were tested intracellularlyin the sartorius muscle of the toad （ Bufo bufo gar-garizans）.TEA （ 10mmol/L）and MnCl₂（10 mmol/L）had no effect on the amplitude of the AP,otherwise,TTX （ 1μmol/L）blocked the AP completely. SC1001Na at the concentration of 2mmol/L largely decreasedthe amplitude of the AP and expanded the du ration ofthe AP（measured at 1/2 peak amplitude）,but it hadno effect on the RP. The effects of group of drugwere reversible. Under the pretreatment of the musclepreparation with TEA（10 mmol/L）,SC1001 Na stillincreased the duration of the AP while decreased itsamplitude. At the concentration of 10mmol/L,SC1001 Na completely blocked AP and depolarized theRP signiiicantly. These effects were not reversible.As the structure of SC1001 Na is different from that ofheterocycloguanidine Na channel blocker l such asTTX, or that of local anestbetics , we infer thatSC1001 Na may be a new sodium channel blocker.更多还原