中文摘要：

目的：研究东亚钳蝎毒素Bukatoxin对大鼠背根神经节（dorsal root ganglion，DRG）神经元河豚毒素不敏感型（tetrodotoxin-resistant，TTX-R）钠离子通道电流（INa）的影响。方法：在急性分离的大鼠DRG神经元上，应用全细胞膜片钳技术，观察Bukatoxin对DRG神经元TIX-R INa的影响。结果：Bukatoxin浓度依赖性地抑制TTX-R INa.在刺激电压为-10mV时，20、40、80μg／ml的Bukatoxin对TTX-R INa峰值的抑制率分别为（18．72±1.27）％、（27．40±4．97）％和（59．02±4．71）％。半数抑制浓度（IC50）为66．28μg/ml，Hill系数（h）为1．48；80μg／ml的Bukatoxin可以使TTX-R INa激活曲线向去极化方向移动约3mV，稳态失活曲线向超极化方向移动6mv。结论：Bukatoxin可以浓度依赖性的抑制DRG神经元上TTX-R INa，并改变TTX-RINa的激活和稳态失活特性，这可能是其降低外周伤害性信息传人，参与伤害性信息调制的机制之一。

英文摘要：

Objective：To study the effects of Bukatoxin on tetrodotoxin-resistant （TTX-R） sodium currents in rat dorsal root ganglion neurons. Methods：The effects of Bukatoxin on TTX-R sodium currents was studied using the whole-cell patch clamp technique in flesh isolated rat dorsal root ganglion neurons. Results：Bukatoxin inhibited TTX-R sodium currents concentration dependently. About 18.72%,27.40% and 59.02% of peak TTX-R sodium currents were inhibited by Bukatoxin at the concentration of 20,40 and 80μg/ml respectively. The activation curve of TrX-R sodium channel was slightly shifted in depolarizing direction by Bukatoxin and the inactivation curve was shifted in hyperpolarizing direction for about 6 mV. Conclusion： Bukatoxin inhibited the TTX-R sodium currents in dose dependent manner, and changed the activation and inactivation of TTX-R sodium channel. This may count for the modulation of Bukatoxint to the nociception transduction.