不同强度电针刺激对失眠大鼠下丘脑orexinA的影响研究

Effect of Electroacupuncture Intensity on OrexinA Expression in Hypothalamus of Insomnia Rats

目的 探讨电针对失眠大鼠下丘脑食欲素A（orexinA）的影响及不同强度电针对orexinA的效应差异。方法将SD大鼠随机分为正常对照组（normalcontrol，NC）、失眠模型组（insomniamodel，IM）、强刺激电针组（strongstimulativeeleetroacupuncture，SSEA）、弱刺激电针组（weakstimulativeelectroacupuncture，WSEA）。除正常对照组外，其余各组大鼠均用对氯苯丙氨酸（PCPA）建立大鼠失眠模型，选穴“百会”、“足三里”、“三阴交”，并用不同强度电针治疗。5d后，用逆转录一聚合酶链反应（RT-PCR）检测下丘脑orexinAmRNA表达，采用免疫组织化学技术观察下丘脑orexinA阳性神经元表达。结果与正常对照组比较，失眠模型组大鼠下丘脑orexinAmRNA表达显著升高（P〈0．01），orexinA阳性神经元染色较深，且表达量较多；与失眠模型组相比，两电针组大鼠下丘脑orexinAmRNA表达明显下降（P〈0．01），orexi—nA阳性神经元染色较浅，表达量较少，强刺激电针组作用更为明显。结论电针可以改善失眠大鼠下丘脑异常增多的orexinA，调节睡眠-觉醒周期，且强刺激电针组效果较好。

Objective To determine the influence of electroacupuncture （EA） intensities on orexinA expression in hypothalamus from insomnia rats, and explore the mechanisms of electroacupun-cture treatment for insomnia Methods SD rats were randomly divided into normal control group （ND, n =10）, insomnia model group （IM, n = 10）, Strong stimulative eleetroacupuncture group （SSEA, n = 10） and Weak stimulative electroacupuncture group （WSEA, n=10） Except normal control group, the models used in the present study were all established PCPA insomnia rats. EA （20 Hz, strong stimulative ： 3 V, weak stimulative ： 1.5 V） was applied to the points of ＂Bai hui＂, ＂Zu san li＂, ＂San yin jiao＂ for 15min everyday and continuously for 5 days. The expression of orexinA mRNA in hypothalamus was detected by RT-PCR. The expression of orexinA positive neurons was detected by immunohistochemistry. Results Compared to ND group, the expression of orexinA mRNA was significantly higher in IM group （P 〈 0.01 ） , showing deeper orexinA staining and higher expression of orexinA positive neurons. After EA stimulation, orexinA mRNA level in insomnia rats and the expression r of orexinA positive neurons were significantly decreased （P 〈 0. 01） . Moreover, the effect of EA was more obvious in SSEA group, compare to WSEA group. Conclusion Electroacupuncture, particularly at SSEA intensity, can alleviate abnormal increase of orexinA in hypothalamus of insomnia rats, thus regulating sleep-wake cycle.