电针对神经病理性疼痛大鼠脊髓背角兴奋性突触重塑的影响

目的观察电针对神经病理性疼痛大鼠脊髓背角兴奋性突触重塑的影响,探讨电针镇痛的效应机制。方法将30只SD大鼠随机分为电针组、模型组、假模组,每组10只。电针组、模型组采用脊神经结扎的方法建立大鼠神经痛模型,假模组仅分离脊神经不结扎。电针组于造模第7天电针大鼠患侧足三里、环跳穴,每次30 min,1次/d,连续7 d,余组仅给予固定,不做治疗。在造模前及造模第3,5,7,9,11,13天分别测定各组大鼠机械缩足反射阈值(MWT)及热缩足反射潜伏期(TWL),造模第14天处死各组大鼠,取大鼠L4~6段腰膨大脊髓,采用免疫组化和Western blot法检测脊髓中GluR1和PSD95蛋白表达情况,采用实时荧光定量PCR检测GluR1和PSD95 mRNA表达水平。结果模型组、电针组大鼠造模后各时间点MWT、TWL均明显低于同期假模组(P均<0.05),但电针组大鼠造模后第9,11,13天MWT、TWL均明显高于同期模型组(P均<0.05)。模型组大鼠脊髓中GluR1、PSD95蛋白及mRNA表达水平均明显高于假模组(P均<0.05);电针组大鼠脊髓中GluR1、PSD95蛋白及mRNA表达水平均明显低于模型组(P均<0.05),但仍明显高于假模组(P均<0.05)。结论电针可能通过调节脊髓背角中突触蛋白GluR1和PSD95的表达,参与兴奋性突触重塑而对神经病理性疼痛产生镇痛效应。

Effect of electroacupuncture on excitatory synaptic remodeling in spinal dorsal horn of rats with neuropathic pain

Objective It is to observe the effect of electroacupuncture on the remodeling of excitatory synapses in the spinal dorsal horn of rats with neuropathic pain,and explore the mechanism of electroacupuncture analgesia.Methods Thirty-six SD rats were randomly divided into electroacupuncture group,model group and sham model group,with 10 rats in each group.The rat neuralgia models were established by spinal nerve ligation in electroacupuncture group and model group.The spinal nerve was only separated without ligation in the sham model group.The rats in the electroacupuncture group were treated with electroacupuncture at Zusanli point,Huantiao point at the affected side on the 7th day of modeling,30min per time,once per day,continuously treated for 7 days.The other two groups were only fixed and given no treatment.Before the modeling and on the 3rd,5th,7th,9th,11th,and 13th days of modeling,the mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL)of rats in each group were measured.On the 14th day of modeling,the rats of each group were sacrificed,and their L4-6 lumbar dilated spinal cords were taken to detect the expression of GluR1 and PSD95 protein in the spinal cord by immunohistochemistry and western blot,GluR1 and PSD95 mRNA by Real-time fluorescence quantitative PCR.Results The MWT and TWL at each time point after modeling in the model group and the electroacupuncture group were significantly lower than those in the sham model group at the same period(P<0.05),but the MWT and TWL in the electroacupuncture group were significantly higher than those in the model group on the 9th,11th,and 13th days of modeling(all P<0.05).The levels of GluR1,PSD95 protein and mRNA expression in the spinal cord of the model group were significantly higher than those of the sham model group(all P<0.05);the levels of GluR1,PSD95 protein and mRNA expression in the spinal cord of the electroacupuncture group were significantly lower than those of the model group(all P<0.05),but it is still significantly higher than those of the sham model group(all P<0.05).Conclusion Electroacupuncture may participate in excitatory synaptic remodeling and has an analgesic effect on neuropathic pain through regulating the expression of synaptic proteins GluR1 and PSD95 in the dorsal horn of the spinal cord.