针刺耳甲区对自发性高血压及正常大鼠血压的影响及其机理探讨

Effect of Acupuncture of Auricular Concha Area on Blood Pressure in Spontaneous Hypertension and Normal Rats and Analysis on Its Mechanism

目的：探讨针刺耳甲区耳穴的降压作用及降压机制。方法：22只正常SD大鼠和15只自发高血压大鼠，氨基甲酸乙酯腹腔注射麻醉（1．0g／kg），观察迷走神经完整和颈部切断迷走神经干后耳甲区电针（75～100Hz，疏密波）和手针（约2次／S）刺激对动脉血压和心率的影响，同时记录左侧迷走神经和交感神经放电的变化。选取“内关”穴作对照。此外，在正常大鼠沿动脉插管推泣1％阿托品（0．05mg／kg）后刺激耳穴以及电刺激正常大鼠迷走神经时，记录血压和心率及神经放电指标。结果：在自发高血压大鼠和正常大鼠。电针和手针刺激耳甲区能有效降低动脉压（P〈0．001），抑制心率（P〈0．001），同时在个例动物观察到迷走神经放电增加而交感神经放电抑制。平补平泻手法针刺“内关”穴也有降压效果（P〈0．05），但与耳甲区针刺结果相比有显著性差异（P〈0．001）。正常动物的降压效果在动脉注射阿托品和迷走神经切断术后消失，而电刺激迷走神经产生类似耳针的降压和减缓心率的效果。结论：耳甲区针刺能有效降低动物的血压，这种降压作用与迷走神经结构和功能的完整性密切相关。

Objective： To observe the effect of acupuncture of auricular concha area on blood pressure （BP） and to explore its mechanism in lowering BP. Methods： Fifteen spontaneous hypertension rats （SHR） and 22 normal SD rats anesthetized with urethane （ 1.0 g/kg） were subjected into the present study. Mean blood pressure of the common cervical artery and activities of the cervical vagus trunk were recorded during electroacupuncture （EA, 75- 100 Hz, dense-sparse waves and duration of 2 min） or manual acupuncture stimulation （about 2 revolutions/s） of the auricular concha and left ＂Neiguan＂ （PC 6）. BP and electrical activities of the left vagus and sympathetic nerve were recorded in some rats. Atropine （ 1%, 0.05 mg/kg） was injected into the carotid artery for observing the effect of EA on BP. Results： In SHR and normal rats, electrical stimulation and manual acupuncture stimulation of both left and right auricular concha could apparently lower blood pressure of the carotid artery in cornparison with the basic values before stimulation （ P〈 0.001 ） ） correspondingly, when manual acupuncture stimulation of both left and right auricular conche induced decline of mean pressure, the vagal activity increased and sympathetic discharges decreased clearly. Manual acupuncture stimulation of ＂Neiguan＂ （PC 6） could also significantly lower BP, but the effect was remarkably weaker than that of stimulation of auricular conche （P〈 0.001）. In vagotomized and atropine-administrated rats, the effect of acupuncture disappeared, while electrical stimulation of vagus could produce auricular concha-acupuncture-like effects in lowering BP and heart rate. Conclusion： Acupuncture of auricular concha has a definite hypotensive effect in both SHR and normal rats, which depends on the integrity of the vagus in both function and structure.