中文摘要：

目的探讨电针口面部四白穴对内脏痛的镇痛作用及传入途径。方法成年SD大鼠30只,随机分为空白组、内脏痛组、电针＋内脏痛组、辣椒素＋电针＋内脏痛组、溶媒＋电针＋内脏痛组,每组6只。空白组大鼠腹腔注射生理盐水;内脏痛组大鼠腹腔注射乙酸造成内脏痛模型;电针＋内脏痛组先电针双侧四白穴20min,再腹腔注射乙酸造成内脏痛模型;辣椒素＋电针＋内脏痛组大鼠首先用辣椒素处理双侧眶下神经,术后5d待其完全恢复后电针双侧四白穴20min,再腹腔注射乙酸造成内脏痛模型;溶媒＋电针＋内脏痛组大鼠用溶媒处理双侧眶下神经,其余处理同辣椒素＋电针＋内脏痛组。各组大鼠处理完毕后,观察大鼠的行为学变化（扭体反应）以及孤束核（nucleusofthesolitarytract,NTS）和三叉旁核（para-trigeminalnucleus,PTN）的c-fos表达。结果 （1）电针＋内脏痛组腹部收缩次数较内脏痛组明显减少（P〈0.01）;辣椒素＋电针＋内脏痛组大鼠腹部收缩次数较电针＋内脏痛组明显增加（P〈0.05）;溶媒＋电针＋内脏痛组大鼠腹部收缩次数较内脏痛组明显减少（P〈0.05）。（2）电针＋内脏痛组NTS的c-fos表达较内脏痛组明显减少（P〈0.05）;辣椒素＋电针＋内脏痛组NTS的c-fos表达较电针＋内脏痛组明显增加（P〈0.01）。（3）电针＋内脏痛组PTN的c-fos表达较内脏痛组明显增加（P〈0.01）;辣椒素＋电针＋内脏痛组PTN的c-fos表达较电针＋内脏痛减弱（P〈0.05）;溶媒＋电针＋内脏痛组PTN的c-fos表达较辣椒素组显著增加（26.3±4.50vs11.7±2.44,P〈0.01）。结论 C纤维在电针口面部穴位对内脏痛的镇痛效应中有重要作用,口面部的躯体感觉传入通过C纤维经PTN中继后与内脏的感觉传入可能在NTS发生汇聚并进行整合,从而产生镇痛作用。

英文摘要：

Objective To Role of C fibers in the analgesia induced by electroacupuncture （EA） at Sibai acupoints on visceral pain （VP） rats. Methods Thirty adult Sprague-Dawley rats were divided randomly into control, VP, EA ＋ VP, Capsaicin ＋ EA ＋ VP and Vehi- cle ＋ EA ＋ VP groups, 6 rats in each group. Visceral pain was induced by intraperitoneal injection of 0. 6% acetic acid and was assessed by counting abdominal contraction. Meanwhile, e-fos expression in the nucleus of the solitary tract （NTS） and paratrigeminal nucleus （PTN） was observed by immunohistoehemistry. Results Following eapsaiein pretreatment （ Capsaiein ＋ EA ＋ VP）, inhibition of EA at ST2 on abdominal contractions induced by acetic acid was significantly attenuated, indicating difference compared to that in EA ＋ VP group （P 〈 0. 05 ）. However, vehicle pretreatment （ Vehicle ＋ EA ＋ VP） produced similar effect to acetic acid injection alone. （2） Following eapsaicin pretreatment, inhibition of pretreatment of EA at ST2 on acetic acid-induced c-fos expression was attenuated. The number of c-los positive neurons in the NtIS had no obvious changes compared to that in VP group, and were higher than those in the EA ＋ VP group （ P 〈 0. 01 ）. Vehicle pretreatment had no effects on the inhibition of pretreatment of EA at ST2 on acetic acid-induced c-fos expression, which was higher than that in the acetic acid injection alone （ P 〈 0. 05 ）. （ 3 ） Compared to that in the EA ＋ VP group, e-fos expression in the PTN attenuated significantly after capsaiein pretreatment （ P 〈 0. 05 ）. Vehicle pretreatment had no significant influences on the e-los expression induced by pretreatment of EA at ST2. Conclusions C fibers play an important role in the analgesia of EA at Sibai acupoints on visceral pain, and so- matic sensory afferents from orofacial areas and visceral sensory afferents could converge and integrate into the NTS via PTN, which is the basis of the analgesia.