Han Yan-Jing, Li Wen-Xun, Jia Bao-Hui, Shi Yu-Jing, Tu Ya
Institute of Acu-moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Zhen Ci Yan Jiu. 2009 Aug;34(4):236-41.
To observe the effect of electroacupuncture (EA) on hippocampal nitric oxide (NO)-cyclic guanosine 3,5-monophosphate (cGMP) signaling pathway in depression rats in order to explore the underlying mechanism of EA in improving depression.
Thirty male SD rats were equally randomized into control, model and EA groups. Depression model was established by using chronic unpredictable mild stress stimulation (forced ice-water swimming, electric shock, tail-clamping, etc.) combined with lonely raising for 21 days. EA (2 Hz, 0.6 mA, 20 min) was applied to "Baihui" (GV 20) and "Yintang" (EX-HN 3), once daily for 21 days. The expression of neuronal nitric oxide synthase (nNOS) and the content of cGMP in the hippocampus were determined by immuno-histochemistry and radioimmunoassay separately.
Many nNOS immuno-reaction (IR)-positive granular cells were observed in the hippocampus in control group, fewer found in EA group and fewest in model group. Image analysis showed that the grey value of model group was significantly higher than that of control group (P < 0.01), and that of EA group was obviously lower than that of model group (P < 0.01), suggesting upregulation of nNOS expression after EA. Compared with control group the content of cGMP in hippocampus in model group showed a decreasing trend, but without significant difference between two groups (P > 0.05). In comparison with model group, hippocampal cGMP content of EA group increased considerably (P < 0.01), being comparable to that of control group (P > 0.05).
Electroacupuncture of "Baihui" (GV 20) and "Yintang" (EX-HN 3) can upregulate the expression of nNOS and the content of cGMP in the hippocampus in depression rats, maintaining a normal activity of the NO/cGMP signaling pathway, which may contribute to its effect in relieving depression.
观察电针对抑郁大鼠海马一氧化氮（NO）-环磷酸鸟苷（cGMP）信号通路的影响，以探讨电针改善抑郁的潜在机制。
30只雄性SD大鼠随机均分为对照组、模型组和电针组。采用慢性不可预测温和应激刺激（强迫冰水游泳、电击、夹尾等）结合孤养21天建立抑郁模型。电针“百会”（GV 20）和“印堂”（EX-HN 3）（2 Hz，0.6 mA，20分钟），每日1次，共21天。分别采用免疫组织化学法和放射免疫分析法检测海马神经元型一氧化氮合酶（nNOS）的表达及cGMP的含量。
对照组海马可见许多nNOS免疫反应（IR）阳性颗粒细胞，电针组较少，模型组最少。图像分析显示，模型组灰度值显著高于对照组（P < 0.01），电针组明显低于模型组（P < 0.01），提示电针后nNOS表达上调。与对照组比较，模型组海马cGMP含量呈下降趋势，但两组间差异无统计学意义（P > 0.05）。与模型组比较，电针组海马cGMP含量显著增加（P < 0.01），与对照组相当（P > 0.05）。
电针“百会”（GV 20）和“印堂”（EX-HN 3）可上调抑郁大鼠海马nNOS表达及cGMP含量，维持NO/cGMP信号通路的正常活性，这可能是其缓解抑郁的作用机制。
