Objective: To observe the effect of electroacupuncture (EA) on behavior, tyrosine hydroxylase (TH), mitochondrial complexes Ⅰ-Ⅳ, mitochondrial membrane potential and mitochondrial ultrastructure of Parkinson's disease (PD) mice, so as to explore its mechanism underlying improvement of PD.
Methods: C57BL/6 mice were randomly divided into normal, model, medication (Madopar) and EA groups (n=11 in each group). PD model was duplicated by intraperitoneal injection of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP, 30 mg·kg-1·d-1) for consecutively 5 d. EA was performed on the chorea tremor areas on both sides of the head of mice for 15 min, once a day for 14 d. The behavioral changes of mice were observed. The expression of TH in substantia nigra compacta of midbrain was detected by immunohistochemistry. The activities of mitochondrial complexes Ⅰ-Ⅳ were measured. The changes of mitochondrial membrane potential were detected by JC-1 staining method. The ultrastructural changes of striatum mitochondria were observed by transmission electron microscope.
Results: After modeling, the mice showed obvious behavioral abnormalities such as tremor, vertical hair and tail warping, and the pole test time in the model group was significantly longer than that in the normal group (P<0.01). After 7 and 14 days of the treatment, the pole test time in the EA and medication groups was shorter than that in the model group (P<0.05，P<0.01). Compared with the normal group, the number of TH positive cells of the substantia nigra, the mitochondrial membrane potential and the activity of mitochondrial complex I were decreased significantly in the model group (P<0.01), and EA and medication intervention reversed these changes (P<0.01). The mitochondrial structure of mice in the model group was obviously damaged, and the damage of mitochondrial structure was alleviated and the number of damaged mitochondria was decreased in the EA and medication groups.
Conclusion: EA can protect and promote the recovery of mitochondrial structure and function in MPTP-induced PD mice, which may play a neuroprotective effect on PD mice by improving mitochondrial dysfunction, balancing cell homeostasis and reducing dopaminergic neuron damage.
目的：观察电针对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)诱导的帕金森病(PD)模型小鼠行为学、酪氨酸羟化酶(TH)、线粒体复合物Ⅰ—Ⅳ活性、线粒体膜电位、线粒体超微结构的影响，探讨电针治疗PD的可能靶点及机制。方法：将雄性C57BL/6小鼠随机分为对照组、模型组、美多巴组及电针组，每组11只，采用MPTP 30 mg·kg-1·d-1连续5 d腹腔注射诱导亚急性PD小鼠模型，对小鼠头部双侧舞蹈震颤区行电针治疗15 min/次，1次/d，连续14 d。观察各组小鼠行为学改变；用免疫组织化学法检测小鼠中脑黑质致密部TH的表达；测定小鼠线粒体复合物Ⅰ—Ⅳ的活性；JC-1染色法检测小鼠线粒体膜电位变化；透射电镜观察小鼠纹状体线粒体超微结构变化。结果：造模后小鼠出现震颤、竖毛、翘尾等明显行为学异常，模型组小鼠爬杆时间较正常组显著延长(P<0.01)；治疗7、14 d后，模型组爬杆时间仍显著长于正常组(P<0.01)，电针组、美多巴组爬杆时间较模型组显著缩短(P<0.05，P<0.01)。与正常组比较，模型组小鼠中脑黑质TH阳性表达、线粒体复合物Ⅰ活性、线粒体膜电位水平显著降低(P<0.01)；与模型组比较，电针组、美多巴组中脑黑质TH阳性表达、线粒体复合物Ⅰ活性、线粒体膜电位水平显著升高(P<0.01)。模型组小鼠线粒体结构破坏明显，电针组、美多巴组线粒体结构损伤减轻，损伤的线粒体减少。结论：电针治疗对MPTP诱导的PD小鼠模型线粒体结构及功能有保护及促进恢复的作用，可能与改善线粒体功能障碍，平衡细胞稳态，减轻多巴胺能神经元损伤有关。.
Keywords: Electroacupuncture; Mitochondrial complex; Mitochondrial function; Mitochondrial membrane potential; Parkinson’s disease.