糖尿病大鼠背根神经节神经元TTX-R钠离子通道电流变化及意义

目的:通过研究大鼠糖尿病神经病理性疼痛(DNP)中背根神经节(DRG)神经元TTX-R钠离子通道特征的变化,以探讨此疾病引起痛觉过敏可能的发生机制。方法:8只SD大鼠腹腔注射链尿佐菌素诱导制作糖尿病神经病理性疼痛模型(DNP组),取L5⁶DRG,贴壁消化法行神经元培养,电生理全细胞膜片钳记录离子通道电流;8只同月龄大鼠为正常对照。结果:大鼠糖尿病神经病理性疼痛小直径DRG神经元TTX-R INa电流密度较对照组增高。与对照组比较激活曲线向超极化移动3.9 mV(P<0.05),DNP组具有重复放电的神经元的比率增加。结论:大鼠糖尿病神经病理性疼痛小直径DRG神经元TTX-R钠通道电流的变化是痛觉过敏形成的原因之一。

Changes and Significance of Tetrodotoxin-resistant Sodium Channels Current of Dorsal Root Ganglion Nociceptive Neurons in Rats with Diabetes

Objective To investigate the characteristic changes of tetrodotoxin-resistant （3WX-R） sodium channels of dorsal root ganglion neuron（DRG） in rats with diabetic neuropathological pain （DNP） , so as to explore the possible mechanism of hyperalgesia induced with DNP. Methods The DNP model was prepared in 8 SD rats with intraperitoneat injection of strep-tozotocin. The neuron was isolated from L5 -6DRG with adherent digestive method and cultured in vitro. The electric current was recorded with electrophysiological whole-cell patch clamp technique. Another 8 SD rats with same month age were selected as control group. Results The electric current density of TTX-R INa of minor diameter DRG in DNP rats was higher than that of control group. The activated curve was moved 3.9 mV to hyperpolarzation compared with control group, the ratio of repetitive discharge neurons in DNP group was significantly increased than that of control group（ P 〈 0.05 ）. Conclusion The electric current change of minor diameter DRG may play an important role in the hyperalgesia of rats with DNP.