电针对面神经损伤兔面神经超微结构的影响

Effect of Electroacupuncture on Ultrastructural Changes of Facial Nerve in Rabbits with Facial Nerve Injury

目的:观察电针对面神经损伤后面神经雪旺细胞形态学的影响,探讨电针治疗周围性面瘫的可能机制。方法:日本大耳白兔分为空白组6只;模型组、假手术组和电针组,每组18只,根据治疗时间分为1、2、3个疗程3个亚组,每组6只。面神经压榨造模后,电针组选取"地仓""颊车""翳风"和"合谷"穴进行电针治疗(疏密波,3Hz/60Hz,30min),5d为一疗程,共治疗3个疗程。运用电镜观察受损面神经和雪旺细胞的形态学改变。结果:正常面神经纤维髓鞘结构完整,髓鞘密集,鲜见脱髓鞘情况;模型组在各时间段面神经出现不同程度的脱髓鞘情况,雪旺细胞结构不完整,细胞器缺失,在髓鞘数量、厚度上显著低于空白组(P<0.01,P<0.05);假手术组脱髓鞘情况以及各时间段髓鞘数量和厚度均优于模型组同期水平;电针组在电针治疗1个疗程后,面神经纤维充血水肿情况与模型组相比较轻,雪旺细胞结构相对较完整,细胞器丰富,髓鞘化程度(髓鞘数量、厚度)明显优于模型组同期水平,第2、3疗程后,髓鞘数量、厚度较前有所减少,面神经修复进程受阻。结论:面神经损伤急性期电针可以加快神经髓鞘化进程,促进受损面神经快速修复,而电针治疗效应不随刺激时长的增长而增加,电针治疗需要把握"中病即止"的原则。

Objective To observe the effect of electroacupuncture （EA） on ultrastructure of facial nerve and Schwann cells in facial nerve injury rabbits so as to explore its mechanism underlying improving facial palsy. Methods A total of 60 Japanese white rabbits were randomly assigned to normal control （normal, n=6）, sham-operation （sham, n = 18）, model （n =18） and EA （n = 18） groups. The facial nerve injury model was established by clamping the right facial nerve for 5 min by using a pair of forceps. EA （1.5V, 3 Hz/60 Hz） was applied to ＂Yifeng＂（TE 17）-＂Hegu＂ （LI4）, and ＂Dicang＂ （ST 4）-＂Jiache＂ （ST6） on the affected side for 30 min, respectively, once daily for 3 weeks. Morphologic changes of the myelin sheath and Schwann cells of the facial nerve were observed by using electron microscope after 1, 2 and 3 weeks＇ treatment. Results Compared with the normal control group, the number of the myelin sheaths and the thickness values of the facial nerve after treatment of 1, 2 and 3 weeks in the model group were decreased significantly （P〈0.01, P〈0, 05）. While in comparison with the model group, the thickness value of the facial nerve 2 weeks after modeling in EA group was increased considerably （P〈0.01）. In the model group, there were many vacuoles in the cytoplasm of Schwann cells instead of organells in the facial nerve, in the sham group, the demyelination was milder than that of the model group, and majority of myelin sheaths showed integral structure after 2 and 3 weeks, being similar to the normal group. Compared with the model group, the extent of demyelination was less distinct, with relatively more abundant organelis in the facial nerve of the EA group, especially after 1 week of treatment. Among the three time points in the EA group, demyelination was milder in the 1^st week not in the other time points. In contrast, along with the continuous EA treatment, the situation became worse after 3 weeks of treatment in the EA group. Conclusion In the acute stage of facial nerve injury, EA intervention can play a positive effect on the repair of the nerve and Schwann cells. However, continuous 3-weeks~ EA intervention may worsen the facial nerve injury.