C纤维在电针口面部穴位镇痛效应中作用.docVIP

C纤维在电针口面部穴位镇痛效应中作用 　 作者：刘健华 符文彬 徐振华 刘雪芳 陈杰斯 【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20 min，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5 d待其完全恢复后电针双侧四白穴20 min，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（nucleus of the solitary tract，NTS）和三叉旁核（paratrigeminal nucleus，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（Plt;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（Plt;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（Plt;0.05）。（2）电针＋内脏痛组NTS的cfos表达较内脏痛组明显减少(Plt;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（Plt;0.01）。（3）电针＋内脏痛组PTN的cfos表达较内脏痛组明显增加(Plt;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(Plt;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±4.50 vs 11.7±2.44，Plt;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。 【关键词】 四白穴；内脏痛；C纤维；孤束核；三叉旁核 【Abstract】 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 Vehicle+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, cfos expression in the nucleus of the solitary tract (NTS) and paratrigeminal nucleus (PTN) was observed by immunohistochemistry. Results Following capsaicin pretreatment (Capsaicin+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 capsaicin pretreatment, inhibition of pretreatment of EA at ST2 on acetic acidinduced cfos expression was attenuated. The number of cfos positive neurons in the NTS had no obvious changes compared t