神经病理性痛大鼠背根神经节神经元钠电流的变化  

Changes of sodium currents in injured dorsal root ganglion neurons in the rat model of neuropathic pain

作　　者：陈晓东 王强[2] 孙晓迪 肖杭[2] 段满林[3] 

机构地区：[1]南京医科大学第一附属医院麻醉科,南京医学硕士210029 [2]南京医科大学现代毒理学教育部重点实验室,南京210029 [3]南京军区南京总医院麻醉科,南京210002

出　　处：《医学研究生学报》2011年第12期1245-1248,共4页Journal of Medical Postgraduates

基　　金：中国博士后科学基金(20080431417;200902694)

摘　　要：目的钠通道在神经病理性疼痛中的作用尚不十分明确,仍有许多疑题待研究。文中研究神经病理性痛模型大鼠背根神经节(dorsal root ganglion,DRG)神经元钠电流的变化。方法 SD雄性大鼠,周龄4～6周,采用结扎L5脊神经的方法建立神经病理性痛模型。于术后14d时采用酶消化法急性分离模型组损伤侧组(SNL组)以及假手术组(Sham组)L5 DRG神经元,采用全细胞膜片钳技术记录神经元钠电流。结果 SNL-L5组DRG神经元河豚毒素敏感型钠电流(TTX-S INa)密度峰值较Sham组增高(P<0.05),河豚毒素非敏感型钠电流(TTX-R INa)密度峰值较Sham组降低(P<0.05)。与Sham组比较,SNL组TTX-S INa的激活曲线向超极化移动了8.5mV(P<0.05),稳态失活曲线变化没有统计学意义(P>0.05);TTX-R INa激活向超极化移动7.4mV(P<0.05),稳态失活曲线向去极化方向移动9.6mV(P<0.05)。结论神经病理性疼痛模型大鼠损伤DRG神经元2种钠电流发生了不同的变化,提示损伤神经元不同类型的钠通道在神经病理性痛过程中发挥着不同的作用。Objective The effects of sodium channels on neuropathic pain are not yet quite clear,with a lot of questions to be answered.This study aimed to investigate the changes of sodium currents in the injured dorsal root ganglion(DRG) neurons in a rat model of neuropathic pain.Methods A neuropathic pain model was established in pathogen-free male SD rats aged 4-6 weeks by L5 spinal nerve ligation(SNL).At 14 d after the operation,L5 DRG neurons were enzymatically dissociated in the SNL and sham-operation groups,and the sodium current of the neurons recorded with the whole cell patch clamp technique.Results Compared with the sham-operation group,the current densities of the TTX-S INa current in the DRG neurons were significantly increased(P<0.05) while those of the TTX-R INa current remarkably reduced in the SNL group(P<0.05).The activation curve for TTX-S INa was shifted to hyperpolarized potentials by 8.5 mV(P<0.05),with no statistically significant difference in the change of the steady-state inactivation curve(P>0.05),while that for TTX-R INa shifted by 7.4 mV(P<0.05),and the steady-state inactivation curve shifted to depolarized potentials by 9.6 mV(P<0.05) in the SNL group as compared with the sham-operation group.Conclusion SNL caused different changes in TTX-S INa and TTX-R INa currents,which suggest that different sodium channels may play different roles in injured DRG neurons.

关 键 词：神经病理性痛 背根神经节 钠电流 膜片钳 

分 类 号：R741[医药卫生—神经病学与精神病学]