中药在外用时有些表现有局部的止痛作用,如川乌、草乌、南星、半夏、蟾酥、细辛等。但有关药理实验研究不多。文献报道细辛煎剂局部应用于阿弗他口腔炎除促进病变的治疗尚有显著的镇痛作用。为了探讨其作用原理,我们利用蟾蜍离体坐骨神经干动作电位的改变作指标观察细辛煎剂对神经干传导的阻滞作用。材料与方法实验材料为蟾蜍坐骨神经标本,并分离全部腓神经与胫神经,全长约6～9厘米。神经标本制备后浸任氏液中15～30分钟待其兴奋性稳定后进行实验,实验时将标本安置 Some Chinese medicines have some local analgesic effects when used on topical medicines, such as Chuanwu, Kusao, Nanxing, Pinellia, wolfberry, and Asarum. However, there are few studies on pharmacological experiments. The literature reported that topical decoction for topical application of aphthous stomatitis has a significant analgesic effect in addition to promoting the treatment of lesions. In order to investigate its principle of action, we used the changes in the action potential of the isolated sciatic nerve of the tibia as indicators to observe the blockade effect of Asarum decoction on the nerve trunk conduction. Materials and Methods The experimental materials consisted of sciatic nerve specimens and all phrenic nerves and sacral nerves were isolated. The total length was about 6-9 cm. After the preparation of the neural specimens, the test was performed after the experiment was performed for 15 to 30 minutes in Renji’s solution and the excitability was stabilized.