Effects of electroacupuncture of different frequencies on free radicals in hippocampus of mice with vascular dementia

Abstract

Objective

To observe the effects of electroacupuncture (EA) of three different frequencies (2 Hz, 80 Hz and 2 Hz/80 Hz) on the free radicals in hippocampus of vascular dementia (VD) model mice.

Methods

A total of 100 Kunming mice were randomly divided into a sham operation group, a model group, a 2 Hz EA group, an 80 Hz EA group and a 2 Hz/80 Hz EA group, with 20 mice in each group. The ischemia-reperfusion VD model was established by repeated blockade of bilateral common carotid arteries. Mice in EA groups began EA treatment on the 4th day after the operation. Baihui (GV 20), Dazhui (GV 14), Geshu (BL 17) and Zusanli (ST 36) were punctured and then connected to EA instrument, with different waves of 2 Hz, 80 Hz or 2 Hz/80 Hz (10 min/time) applied accordingly, once a day. During the jumping stand experiment, the learning performance, memory performance and hippocampal calcitonin gene-related peptide (CGRP), nitric oxide synthase (NOS), malondialdehyde (MDA), changes in superoxide dismutase (SOD) and true choline esterase (TChE) were observed. In hippocampus, the CGRP level was determined by radioimmunoassay; the MDA level was determined by thiobarbituric acid colorimetric method; the activities of NOS and TChE were determined by spectrophotometry; the activity of SOD was determined by xanthine oxidase method.

Results

Compared with the sham operation group, the performances of learning and memory decreased significantly in the model group (P<0.01); in hippocampus, the CGRP level decreased, the MDA level increased, the activities of NOS and TChE increased, and the activity of SOD decreased in the model group. Compared with the model group, the learning and memory performances of the EA groups were significantly improved (P<0.05 or P<0.01); in hippocampus, the CGRP level increased, the MDA level decreased, the NOS and TChE activities decreased, and the SOD activity increased (P<0.05 or P<0.01). Among EA groups, the 2 Hz/80 Hz EA group was superior to the 2 Hz EA group and the 80 Hz EA group (P<0.05 or P<0.01).

Conclusion

EA can improve the cognitive impairment of mice with ischemia-reperfusion VD. The mechanism may be related to the improvement of cerebral blood circulation, regulation of the central neurotransmitters, fighting lipid peroxidation and promoting nerve cell repair. The therapeutic effects of EA with different frequencies were different, and the intervention effect by EA at 2 Hz/80Hz is the most significant.

摘要

目的

观察2 Hz、80 Hz和2 Hz/80 Hz三种不同频率电针对血管性痴呆(VD)模型小鼠海马组织自由基影响的差异性。

方法

将100只昆明小鼠随机分为假手术组、模型组、2 Hz电针组、80 Hz电针组和2 Hz/80 Hz电针组, 每组20只。以反复阻断双侧颈总动脉方法复制缺血再灌注VD模型。电针各组于术后第4 d开始治疗。选取百会、大 椎、膈俞和足三里, 毫针刺入后接电针仪, 分别施以疏波2 Hz、密波80 Hz和疏密波2 Hz/80 Hz干预, 每次10 min, 每日1次。观察各组小鼠跳台实验学习成绩、记忆成绩及海马组织降钙素基因相关肽(CGRP)、一氧化氮合成酶(NOS)、 丙二醛(MDA)、 超氧化物歧化酶(SOD)及乙酰胆碱酯酶(TChE)的变化。采用放射免疫法测定海马组织CGRP含量, 硫代巴比妥酸比色法测定MDA含量, 分光光度法测定NOS、TChE活性, 黄嘌呤氧化酶法测定SOD活性。

结果

与假手术组比较, 模型组小鼠学习成绩与记忆成绩明显下降(P<0.01); 海马组织CGRP含量降低, MDA含量升高; NOS、TChE活性提高, SOD活性下降。与模型组比较, 电针各组学习成绩、记忆成绩明显提高(P<0.05或P<0.01); 海马组织CGRP含量提高, MDA含量降低; NOS、TChE活性降低, SOD活性提高(P<0.05或P<0.01)。电针组比较, 2 Hz/80Hz EA 组优于2Hz EA组和80 Hz EA组 (P<0.05或P<0.01)。

结论

电针可改善缺血再灌注VD模型小鼠的认知障碍, 其机制可能与电针改善脑部血液循环, 调节中枢神经递质,对抗脂质过氧化损伤, 进而促进神经细胞修复有关。不同频 率电针的治疗效应存在一定差异, 2 Hz/80Hz干预效应最突出。