Effects Of Electroacupuncture On Glucose Uptake And Expression Of Glucose Transporter-3 In Medial Prefrontal Cortex Of CCI Rats

Objective:To observe the effects of electroacupuncture on the medial prefrontal cortex（mPFC）18F-FDG uptake rate and glucose transporter-3（GLUT-3）in rats with neuropathic pain,and to explore the possible central mechanism of electroacupuncture analgesia in order to explain some mechanisms of acupuncture analgesia.Methods:Fifty-four healthy male clean SD rats were randomly divided into sham operation group（N=18）,model group（N=18）,and electroacupuncture group（N=18）.The model group and the electroacupuncture group were ligated with 4-0 chromium intestinal suture around the right sciatic nerve to establish the rat model of chronic constriction injury（CCI）neuropathic pain.Sham operation group were same as model group operation,but just exposed right sciatic nerve without ligation.The electroacupuncture group given electroacupuncture treatment on the right side acupoints of"Huantiao"and"Yanglingquan",once a day,every30 minutes,continue treat 7 days.The model group and the sham operation group are equally grasped and fixed without any intervention.Von-Frey fibrous hair and bolometer were used to measure the mechanical withdrawal threshold and paw withdrawal mechanical threshold of rats.Micro PET/CT was used to observe the ¹⁸F-FDG uptake rate of mPFC in the rats brain before and after intervention to reflect the mPFC glucose uptake rate of the rats;The expression of mPFC glucose transporter-3 was detected by immunohistochemical and Elisa.Result:（1）Behavioral results showed that,compared with the sham operation group,the CCI rats in the model group and the electroacupuncture group were mechanical and heat hyperalgesia on the7th day after surgery,and the mechanical withdrawal threshold and paw withdrawal mechanical threshold were significantly reduced.It was statistically significant（P<0.01）;on the 14th postoperative day,compared with the model group,the mechanical withdrawal threshold and paw withdrawal mechanical threshold of the acupuncture group were significantly increased,and the differences were statistically significant（P<0.01）.（2）Micro PET/CT ¹⁸F-FDG imaging results showed that on the 7th postoperative day,compared with the sham operation group,the glucose metabolism of mPFC on the left side of the CCI rats in the model group and electroacupuncture group increased,and the ¹⁸F-FDG intake rate increased.The difference was statistically significant（P<0.05）;on the 14th postoperative day,compared with the model group,the ¹⁸F-FDG intake rate of mPFC on the left side of the CCI rats in the electroacupuncture group decreased,and the difference was statistically significant（P<0.05）.（3）Immunohistochemical results showed that on the 14th day after operation,compared with the model group,the average optical density of GLUT-3 of mPFC on the left side of the CCI rats in the electroacupuncture group decreased,and the difference was statistically significant（P<0.01）.（4）Elisa test results showed that on the 14th postoperative day,compared with the model group,the GLUT-3 concentration of mPFC on the left side of the CCI rats in the electroacupuncture group decreased,and the difference was statistically significant（P<0.01）.Conclusions:（1）The mechanical withdrawal threshold and paw withdrawal mechanical threshold of CCI rats are significantly reduced,the glucose uptake rate of mPFC on the left is increased,and GLUT-3 expression is increased.（2）Electroacupuncture"huantiao"and"Yanglingquan"can significantly improve the pain sensitivity of neuropathic pain,increase the mechanical withdrawal threshold and paw withdrawal mechanical threshold.The analgesic mechanism may be related to the down-regulation of GLUT-3 expression in mPFC and the reduction of mPFC glucose metabolism.