不同强度电针对痛觉异常治疗作用的比较

A COMPARISON OF THERAPEUTIC EFFECTS INDUCED BY ELECTROACUPUNCTURE OF DIFFERENT INTENSITIES ON PARALGESIA IN THE RAT

在正常动物电针强度是一个获取好的镇痛作用的重要因素，那么在病理模型上究竟以何种强度为好呢？本文对此进行了比较研究。在坐骨神经损伤及佐剂性关节炎引起痛觉过敏的大鼠上，通过测定基础痛阈（辐射热缩腿反应潜伏期或压足心缩腿反应的压力）和电针后即时痛阈的变化，比较研究了强和弱（２～３ｍＡ和＜１ｍＡ，５０Ｈｚ）电针的镇痛作用，和对痛觉过敏的治疗作用。结果表明，强电针可获较好的即时镇痛作用，而在治疗痛觉过敏方面却没有显示明显的差别。说明在病变引起的神经可塑性变化基础上，弱电针就可取得较好的治疗作用。

The intensity of electroacupuncture(EA) stimulation has been shown to be one of the important factors for obtaining good analgesic effect in normal animals. In this paper,experiments were designed to explore if the intensity in terms of miliamperes plays an important role in EA-induced therapeutic effect on hyperalgesia in pethophysiological models.It was found that in rats with nerve injury or arthritis, the thermal or mechanical pain threshold measured by heat radiation or pressure- leg withdrawal reflex was significantly lowered.Two to four days after the induction of nerve injury or arthritis,electroacupuncture with strong(2-3mA) or weak(<1mA) intensity was given once every other day at ipeilateral Huantiao and Yanglinquan points or bilateral Huantiao points (50Hz,0.3ms). In two acupuncture groups, hyperalgesia was much weaker and recovered much quicker than that in the control group without any treatment. Though the instant analgesic effect induced by strong EA was more significant than that by weak EA,the therapeutic effects on hyperalgesi a in the whole experiment were not significantly different between strong and weak EA groups.It is suggested that in pethophysiological models with neuroplastical changes,weak EA(activating only large fibers) may be enoush to attenuate the hyperalgesia induced by nerve injury and arthritis. However,the instant analgesic effect induced by strong EA may still be useful for suppressing acute pain syndroms.