针刺镇痛具有较大的个体差异性。不论在针麻临床实践中

在正常人体测痛中

或实验动物中均观察到类似的现象。这种差异的原因是什么?能否用简便的方法加以预测?一直是针刺镇痛原理研究和针麻临床实践中的一个引人注目的课题。近年来镇痛原理研究的大量工作证明

中枢神经系统中存在着内源性的镇痛系统

各种镇痛措施如针刺、吗啡等虽然作用方式和途径Experiments were performed in a group of 113 rats. The basic pain threshold

the effect of electroacupuncture analgesia and the effect of morphine analgesia were measured using radiant heat induced tail flick latency as the nociceptive test. The results are as follows. 1. A Positive correlation was found between the effect of electroacu- neture analgesia and basic pain threshold with a correlation coefficient (r of 0.04

P<0.01. The results indicate that the individual variation in the effectiveness of acupuncture analgesia maybe related with the basic activity level of the endogenous analgesia system. 2. There is a positive correlation between the the effect of electroa- cupuncture analgesia and the effect of morphine analgesia (3mg/kg) (r= 0.76

P<0.001). The result suggests that these two analgesic effects may share a common underlying mechanism. 3. Measuring the analgesic effect elicited by a small dose of morphine in pre-operative patients may have some implication in predicting the efficacy of acupuncture analgesia during surgical operation.