腰交感神经节射频热凝对糖尿病周围神经病变大鼠外周神经功能和结构的影响

摘要

目的 建立糖尿病周围神经病变大鼠模型,采用射频热凝毁损腰交感神经节,观察大鼠外周神经功能和结构的变化.方法 腹腔注射链尿佐菌素诱导糖尿病周围神经病变大鼠模型,选择造模成功的大鼠20只,随机分为糖尿病对照组(Ⅱ组)及交感神经节射频热凝组(Ⅲ组),另选择10只同月龄健康大鼠为正常对照组(Ⅰ组).Ⅲ组大鼠在X光机介导下行右侧L3,L4椎旁腰交感神经节射频热凝毁损.分别于0周、4周时,测定大鼠坐骨神经外膜血流量和运动神经传导速度(motor nerve conductive velocity,MNCV),4周时采用透射电镜观察大鼠腓肠神经超微结构.结果 与Ⅰ组比较,0周时Ⅱ组和Ⅲ组MNCV降低(P＜0.01);射频热凝后4周Ⅲ组较Ⅱ组MNCV升高,但仍较Ⅰ组降低(P＜0.05).与Ⅰ组比较,0周时Ⅱ组Ⅲ组神经外膜血流量降低(P＜0.01);4周时Ⅲ组神经外膜血流量高于Ⅱ组(P＜0.01),与Ⅰ组比较无统计学差异(P＞0.05).Ⅰ组髓鞘排列均匀,轴突内可见形态正常的线粒体;Ⅱ组脱髓鞘明显,髓鞘板层排列紊乱、断裂、肿胀;Ⅲ组脱髓鞘程度明显减轻,髓鞘板层局部排列紊乱、空泡形成.结论 腰交感神经节射频热凝可显著增加糖尿病周围神经病变大鼠坐骨神经外膜血流量,促进受损外周神经超微结构和功能的恢复.%Objective To observe the effect of lumbar sympathetic ganglion lesion by radiofrequency thermalcoagulation on the microstructure and function of peripheral nerve in diabetic neuropathic rats.Methods 20 diabetic neuropathic rats induced by streptozotocine(STZ)60 mg/kg intraperitoneal injection were randomly divided into diabetic group(Ⅱgroup)and radioffequency group(Ⅲ group),meanwhile 10 another normal age-matched rats were determined as controlled group(Ⅰ group).The rats in Ⅲ group received procedure of L3、L4 lumbar sympathetic ganglion lesion by radiofrequency thermalcoagulation on the right side.The blood samples were collected from vena caudalis for determination of the value of blood sugar at 0w and 4w.The motor nerve conductive velocity(MNCV)and blood flow of epineurium in the sciatic nerve were measured at 0w and 4w.The microstructure of sural nerve was observed via transmission electric microscope at 4w.Results Diabetic rats of both Ⅱ and Ⅲ groups demonstrated a significant reduction in MNCV at 0w compared with Ⅰ group(P＜0.01),while at 4w after lumbar sympathetic ganglion lesion the MNCV of Ⅲ group was higher than that of Ⅱ group and lower than that of Ⅰ group.The blood flow of epineurium in Ⅱ and Ⅲ groups was decreased dramatically at 0w.reached normal in Ⅲ group and still was lower in Ⅱ group at 4w when compared with Ⅰ group.Obvious demyelination in sural nerve was observed in Ⅱ group,accompanied by swelling and disordered array of myelin.The degree of sural nerve demyelinatation was ameliorated in the treatment of lumbar sympathetic ganglion lesion.Conclusion Lumbar sympathetic ganglion lesion by radiofrequency thermalcoagulation could enhance the blood flow of epineurium in the sciatic nerve,and therefore improve the microstructure and function of impaired peripheral nerve.