寻找一个较为理想的针刺镇痛模型是深入研究针刺镇痛原理的重要前提

为此我们对钾离子透入甩尾测痛法及其在针刺镇痛模型上的应用作了一些探索.实验方法【测痛电极的制作】取两条胶布(1×3.5厘米)

剪一窄而长锡薄纸(宽约0.4厘米)固定在胶布上

胶布两端露出锡纸约0.5厘米

以备与导线上的夹子相连接。然后把分别浸泡有饱和氯化钾溶液及生理盐水的棉花条放在锡纸中间

此电极即可备用。实验前用酒精棉球擦净鼠尾

A model of acupuncture analgesia in rats was established.On this model the potassium iontophoresis tail-flick method for measuring pain was used. The stimulating electrode was very simple and convenient.It was made of two narrow pieces of silver paper on which a little piece of cotton sep- aratly saturated with KCI(saturated sulution)or NaCl(0.9%)was put. In experiments the electrodes should be tightly fixed on the tail of rat with a strip of adhesive plaster. The apparatus for measuring pain has a negative feedback circuit.So the stimulating current may increase smoothly and is not influenced by any changes from the organism impedence. Electro-acupuncture was given bilaterally at“pishu”with 60 cps.1-2 mA;“zusanli”with 20 cps

2-4 mA. 168 out of 195 rats weighing 150-250g had a comparatively stable pain threshold within one hour or even longer.The range of fluctuation of the pain threshold was+7.1～-7.8%. After electro-acupuncture induction for 10-15 minuts

the pain thres- hold increased from 0.64±0.03 mA to 1.44±0.05 mA in 35 out of 45 rats. The difference between the values before and after aupuncture was statist- ically significant(P<0.001).But the pain threshold in control rats rem- ained unchanged during the whole process of the experiment. This model has been used for studying the mechanism of acupuncture analgesia.