苦参碱抑制SNL大鼠背根神经节TNF-α的表达

MATRINE INHIBITS THE EXPRESSION OF TNF-α IN THE DORSAL ROOT GANGLION IN RATS

目的:观察苦参碱对脊神经损伤所致大鼠神经病理性疼痛的作用,并初步探讨其作用机制。方法:第1组实验将大鼠随机分为25 mg/kg、50 mg/kg、100 mg/kg和200 mg/kg剂量组,每组又分别随机分为实验组和对照组,实验组给予不同剂量苦参碱,对照组给予相应体积溶剂,各组大鼠于术后第8 d利用行为学测试的方法,检测苦参碱对大鼠50%机械刺激撤足阈值及热刺激撤足潜伏期的影响。第2组实验将大鼠随机分为假手术组、模型组、25 mg/kg给药剂量组、50 mg/kg给药剂量组、100 mg/kg给药剂量组、200 mg/kg给药剂量组,实验组给予不同剂量溶剂,余组给予相同体积的溶剂。各组大鼠于第8 d给药后3 h,利用免疫组化的方法检测大鼠背根神经节TNF-α的表达。结果:50 mg/kg以上剂量苦参碱可显著提高模型大鼠50%机械刺激撤足阈值及热刺激撤足潜伏期,低于此剂量无效。50 mg/kg、100 mg/kg和200 mg/kg苦参碱对模型鼠50%机械刺激撤足阈值及热刺激撤足潜伏期提高作用可达6 h以上。通过免疫组化结果可以看出,50 mg/kg、100 mg/kg和200 mg/kg苦参碱能够抑制背根神经节神经元内TNF-α的表达。结论:苦参碱可缓解腰5脊神经切断引起的神经病理性疼痛,其作用可能与抑制背根神经节内TNF-α的表达有关。

Objective： To investigate the effect of matrine on neuropathic pain induced by lumbar 5 spinal nerve ligation in rats and the possible mechanisms underlying matrine analgesia.Methods： In Group 1,the rats were randomly divided into 25 mg/kg,50 mg/kg,100 mg/kg and 200 mg/kg dose groups and rats in each dose group was randomly divided into experimental group and control group.The experimental groups were given different doses of matrine and the control groups were given the corresponding volume of solvent.Eight days after the operation,behavioral methods were used to test the effect of the matrine on the 50% mechanical stimulation foot withdrawal threshold and the latency of the thermal stimulation foot withdrawal in rats.In Group 2,the rats were randomly divided into sham operation group,model group,25 mg/kg dose group,50 mg/kg dose group,100 mg/kg dose group and 200 mg/kg dose group.The experimental groups were given different doses of solvent,other groups were given the same volume of solvent.The expression of the TNF-α in rat dorsal root ganglion was detected with immunohistochemistry three hours after administration at Day 8.Results： At doses of 50 mg/kg,100 mg/kg and 200 mg/kg matrine significantly improved the 50% mechanical stimulation foot withdrawal threshold and the latency of the thermal stimulation foot withdrawal,which lasted more than 6 h,while doses less than 50 mg/kg were ineffective.Immunohistochemistry results indicated that 50 mg/kg,100 mg/kg and 200 mg/kg matrine could inhibit the expression of the TNF-α in the dorsal root ganglion neurons.Conclusion： Matrine is capable of relieving neuropathic pain induced by peripheral nerve injury by inhibiting the expression of the TNF-α in rat dorsal root ganglion.