【摘要】 依据坐骨神经钳夹术后不同类别纤维再生速率的不同，观察了粗纤维（Ａ类）和细纤维（Ｃ类）与针刺足三里镇痛的关系。实验组大鼠神经钳夹损伤后依次存活１０、１５、２０、２５、３０ｄ，测定痛阈、屈肌反射检测及ＨＲＰ逆行束路追踪。结果神经损伤后１０ｄ以前，电针刺激足三里痛阈差为０．０５４ｍＡ，在与坐骨神经相连属的脊神经节内均为小圆形ＨＲＰ标记细胞（＝８．７），仅见Ｃ类纤维传入所引起的屈肌反射；１５ｄ时，电针刺激痛阈差为０．１９６ｍＡ，此时脊神经节内除小圆形细胞外，出现大型ＨＲＰ标记细胞（＝３．３），屈肌反射可见长潜伏期的Ｃ类纤维传入反应及短潜伏期的Ａ类纤维传入反应。２０ｄ后，痛阈差的恢复与脊神经节内的大型标记细胞呈同步增长趋势。结果提示：针刺足三里主要通过Ａ类纤维发挥镇痛效应，Ｃ类纤维不是针刺镇痛的主要传入纤维。更多还原

【Abstract】 The aim of this study is to observe the nerve mechanism of analgesic effect of electroacupuncture(EA) into Zusanli point. With the electro-physiological and nerve path-tracing combined methods, the relation between analgesic effect of EA into Zusanli and A-afferent fiber,C-afferent of sciatic nerve was observed. 30 rats were divided into 6 groups(the rats in Group 1 lived for 10 days;Group 2,15 days;Group 3, 20 days; Group 4, 25 days; Group 5 and Group 6, 30 days), and all were done in left legs. The experimental steps were taken as below:①the basic levels of pain threshold were measured before and after EA into Zusanli;②sciatic nerve was severed in Group 1 to 5 and sham operation was done in Group 6;③according to various survival time, 48 hours before sacrificed, the pain threshold was measured again and flexion reflex was observed;④the HRP labelled cells in the spinal ganglions (L 4-6) were observed. The results showed that:①in Group 1 to 5,the pain threshold increased gradually,②only small round labelled cells were observed in Group 1,both small and big labelled cells were observed in spinal ganglion of Group 2 to 5;③in Group 2 to 5,the flexion reflex was evoked by both A-afferent fiber and C-afferent fiber reaction,and only C-afferent fiber reaction was observed in Group 1. The conclusion is that:the analgesic effect of EA into Zusanli is closely related with sciatic nerve; the analgesic effect can be obtained by transmitting of A-afferent fiber,but not C-afferent fiber.更多还原