The Study Of Electroacupuncture On The Analgesic Mechanism Of Sciatic Nerve Ligation Model Rats

Objective:The aims of this study is to explore the molecular mechanism of electro-acupuncture in the treatment of neuropathic pain by useing sciatic nerve ligation model rats.Methods:Forty Wistar rats were randomly divided into four groups: sham-operated group,model group,electro-acupuncture group,acupuncture group.Rats in model group,electro-acupuncture group and acupuncture group were sciatic nerve ligation model rats.Behavioral testing was conducted prior to surgery and on days 3,7,11,15 and 19 following surgery.The electro-acupuncture group and the acupuncture group were given electro-acupuncture or acupuncture intervention on the 7th day after operation and lasted for 14 days.The expression of GABAA,KCC2,NMDAR and GLT-1 in spinal cord lumbar enlargement was detected by fluorescence quantitative PCR,Western Blot and immunohistochemistry.Results:There was no significant difference in preoperative MWT and PWT between each group(P>0.05);the MWT and PWT of model group decreased from the 3rd to 19 th day after operation,and the pain threshold reached the lowest value on the 7th day after operation,which was significantly different from that of sham-operation group(P<0.05).MWT and PWT in electro-acupuncture group and acupuncture group increased significantly from the 7th day after electro-acupuncture or acupuncture intervention(P<0.05).(2)Quantitative fluorescence PCR showed that compared with sham-operated group,the expression of NMDAR,GABAA and KCC 2 in model group increased(P<0.05),while that of GLT-1 decreased significantly(P<0.01).Compared with model group,the expression of NMDAR in electro-acupuncture group and acupuncture group decreased(P<0.05),while the expression of GABAA,KCC2 and GLT-1 increased(P<0.05).However,there was no significant difference in the expression of each index between the electro-acupuncture group and the acupuncture group(P>0.05).(3)The results of Western Blot showed that compared with sham-operated group,the expression of NMDAR protein in model group was significantly increased,while the expression of GABAA,KCC2 and GLT-1 protein was significantly decreased(P<0.05);compared with model group,the expression of NMDAR protein in electro-acupuncture group and acupuncture group was decreased,and the expression of GABAA,KCC2 and GLT-1protein was increased,with statistical significance(P<0.05).(4)Immunohistochemical results showed that compared with sham-operated group,the expression of NMDAR protein in model group was significantly increased,while the expression of GABAA,KCC2 and GLT-1 protein was significantly decreased(P<0.05);compared with model group,the expression of NMDAR protein in electro-acupuncture group and acupuncture group were decreased,and the expression of GABAA,KCC2 and GLT-1 protein were increased,with statistical significance(P<0.05).Conclusion:Electro-acupuncture can up-regulate the expression of KCC2,and increase the neurosuppressive effect and reduce the excitability of nerves,thus reducing the mechanical and thermal hyperalgesia in rats,so as to achieve the goal of treatment by up-regulating the expression of KCC2.KCC2 is a bridge between nerve excitatory system and inhibitory system.It is an important target for electroacupuncture to treat neuropathic pain and maintain nervous system homeostasis.