神经病理性疼痛小鼠背根神经节河豚毒素敏感型钠电流的变化特征

Alteration of tetrodotoxin-sensitive sodium currents in dorsal root ganglion neurons in chronic constriction injury mice

目的在小鼠坐骨神经慢性压迫性损伤(CCI)模型上,观察背根神经节(DRG)细胞河豚毒素敏感型(TTX-S)钠电流的变化特征。方法采用全细胞膜片钳技术分别记录CCI模型及正常小鼠DRG细胞TTX-S钠电流,比较其电流变化特征。结果 CCI模型小鼠热疼痛阈值较正常小鼠下降约50%。在CCI小鼠DRG细胞上,TTX-S钠电流较正常组明显增加,最大激活电压由-10 m V左移为-20 m V,最大激活电流也由正常组的-(96.3±7.7)p A/p F增加至-(146.6±12.7)p A/p F,其稳态激活和失活曲线分别向较负和较正电压方向偏移14.9和5.1 m V,但通道失活后恢复动力学特征不变。结论 CCI小鼠增加TTX-S钠电流。

Objective To study alteration of tetrodotoxin - sensitive （ TYX - S） sodium currents （ IN, ） in dorsal root ganglion （DRG） neurons in chronic constriction injury （CCI） of mouse sciatic nerve. Methods The whole - cell patch clamp technique was used. Resuits The thermal pain threshold of CCI mice was decreased by about 50% compared with normal mice. In CCI mice ,33＇X - S sodium currents were m^rkedly increased,with the activation potential of the maximal INashifted from - 10 mV to - 20 mV, and the value of the maximal IN, significantly increased from - （96.3 ± 7.7）pA/pF in control to - （146.6 ± 12.7 ）pA/pF in CCI. The steady state activation and inactivation crones were shifted towards more negative and positive potentials by 14.9 mV and 5.1 mV,respectively,yet with dllterence on from inactivation of TFX - S sodium channel. Conclusions TTX - S sodium cmTent was markedno significant J recovery ly increased in DRG neurons in CCI mice.