不同刺激强度电针对正常大鼠大脑p-Akt表达的影响

Effect of Different Stimulus Intensities of Electroacupuncture on the Expression of Phospho-Akt in Rat Brain

目的:探讨相同穴位不同刺激强度电针的作用机理。方法:实验设对照组、中强度电针组、高强度电针组,分别电针“阳陵泉”“足三里”。中强度电针参数:2～4mA、20/4Hz,高强度电针参数:5～7mA、20/4Hz,60min后出针。隔日1次,针刺3次后观察对正常鼠脑pAkt表达的影响。采用免疫组化染色和SDSPAGE电泳蛋白质分析技术观察pAkt在海马CA1区、齿状回及皮质的表达。结果:中强度电针组pAkt在海马CA1区、齿状回及皮质的阳性细胞表达明显多于高强度电针及对照组,统计学分析有显著性差异。结论:不同强度的电针在促进pAkt在海马CA1区、齿状回及皮质的表达中的作用不同。

Objective: To investigate the mechanism of the effects of different stimulus intensities of electroacupuncture (EA) at the same acupoint. Methods: 11 adult Wistar rats were divided into control group (n=3), moderate EA group (n=4) and strong EA group (n=4). EA (moderate intensity: 2～4 mA, 20/ 4 Hz; high intensity: 5～7 mA, 20/4 Hz) was applied to “Yanglingquan”(GB 34) and “Zusanli”(ST 36) for 60 min, once every other day, 3 times altogether. On the 7 th day, these rats were decapitated for taking brain tissue which was then cut into sections (10 μm) to be mounted to glass slides. The expression of phospho-Akt in hippocampus (CA1), dentate gyrus and cerebral cortex of the rats was examined by immunohistochemistry and Western blot analysis. Results: Immunohistochemical results showed that the p-Akt expression-positive neurons in CA1, dentate gyrus and cerebral cortex of moderate EA group were significantly more than those of strong EA and control groups (P<0.01). P-Akt positive neurons of the cerebral cortex in strong EA group were significantly more than those of control group (P<0.05), but no marked differences were found between strong EA and control groups in p-Akt expression positive neurons in CA1 and dentate gyrus (P> 0.05). Results of Western blot were similar to those of immunohisochemical staining. Conclusion: Moderate intensity EA is superior to strong EA in promoting the expression of p-Akt in rat hippocampal CA1, dentate gyrus and cerebral cortex.