东亚钳蝎毒素多肽对河豚毒素敏感型钠电流的作用  

Effects of polypeptide purified from Buthus martensi Karsch on tetrodotoxin-sensitive sodium channels in rat dorsal root ganglion neurons

作　　者：安珊珊[1] 汪溪洁[1] 许鹏[1] 孙芹[1] 陈晓东[2] 程洁[1] 高蓉[1] 肖杭[1] 

机构地区：[1]南京医科大学现代毒理学教育部重点实验室江苏省医学动物实验基地,江苏南京210029 [2]徐州医学院麻醉学院,江苏徐州221002

出　　处：《医学研究生学报》2009年第6期564-569,共6页Journal of Medical Postgraduates

基　　金：国家自然科学基金资助项目(批准号:30271137);高校博士学科专项科研基金资助项目(批准号:20060312001)

摘　　要：目的:蝎毒素是一种神经毒素,其对周围神经系统钠通道的作用尚不十分清楚,仍有许多疑题待研究。文中研究东亚钳蝎毒素多肽224(BmK224)对大鼠背根神经节(DRG)神经元电压依赖性河豚毒素敏感型钠电流(TTX-S INa)的影响。方法:分离单个DRG神经元,应用全细胞膜片钳技术观察BmK224对TTX-S INa的影响。结果:BmK224浓度依赖性地抑制TTX-S INa,40μg/m lBmK224使TTX-S INa稳态激活和失活曲线都向超极化方向移动,复活时间延长,可激活通道数增加。结论:BmK224影响钠通道激活失活过程的作用机制可能是所含的α-蝎毒素使钠通道构象发生改变。Objective ： Scorpion toxin is a neurotoxin, whose effects on the sodium channels of the pe- ripheral nervous system are not yet quite clear, with a lot of questions to be studied. This study aimed to investigate the effects of scorpion polypeptide purified from Buthus martensi Karsch 224 （BmK224） on the tetrodotoxin-sensitive sodium currents （TFX-S INa） in the isolated rat dorsal root ganglion （DRG） neurons. Methods： We isolated the dorsal root ganglion neurons from rats, and observed the effects of BmK224 on TTX-S INa using whole cell patch clamp recordings. Results： BmK224 blocked the whole cell TTX-S IN. in a concentration-dependent manner. At the concentration of 40 μg/ml, it induced the negative shifting of the TTX-S INa activation curve, shifted the steady-state inactivation curve to the left, delayed the recovery of TFX-S INa from inactivation, and increased the fraction of available sodium chan- nels. Conclusion ： This study suggests that BmK224 contains α- scorpion toxins, which lead to the al- teration of the conformation of sodium channels.

关 键 词：东亚钳蝎 蝎毒 河豚毒素敏感型钠通道电流 膜片钳 

分 类 号：R338[医药卫生—人体生理学]