口面部穴位对内脏感觉的调控作用及其途径

Regulation of electroacupuncture at orofacial acupoints on visceral sensation and its pathway

目的探讨电针口面部穴位对内脏感觉的调控作用及其途径。方法成年SD大鼠30只,随机分为生理盐水组、内脏痛组、四白穴组、阳白穴组、颊车穴组,每组6只。生理盐水组腹腔注射0.9%生理盐水(1ml/100g),不给予其他任何处理;内脏痛组腹腔注射乙酸造成内脏痛模型后不给予其他任何处理;四白穴组先电针双侧四白穴20min,再腹腔注射乙酸造成内脏痛模型;阳白穴组和颊车穴组除电针穴位不同外,其余处理同四白穴组。处理完毕后,观察大鼠的行为学变化(扭体反应)以及孤束核(NTS)和三叉旁核(PTN)的c-fos表达。结果 (1)大鼠腹腔注射0.6%的乙酸后,引发典型的内脏痛行为反应(扭体反应)。电针四白穴和颊车穴预处理后,由内脏痛引发的腹部收缩次数明显减少,与内脏痛组比较均有显著差异(P<0.01,P<0.05);电针阳白穴对内脏痛大鼠腹部收缩的次数无明显影响。(2)电针四白穴预处理后,内脏痛所致NTS的c-fos表达明显减少,与内脏痛组比较有显著差异(P<0.05);电针颊车穴亦产生类似的作用;电针阳白穴作用不明显。(3)电针阳白穴预处理PTN的c-fos阳性神经元数目与内脏痛组比较无明显变化。电针四白穴预处理后,三叉旁核的c-fos表达较阳白穴组明显增加(P<0.01);电针颊车穴亦出现与四白穴类似的效应。结论 (1)电针口面部穴位对大鼠内脏痛有显著的镇痛效应,且表现出一定的穴位特异性,与穴位的神经支配密切相关。(2)面口部穴位的躯体感觉传入可能经PTN中继后与胃肠道的内脏感觉传入在NTS发生汇聚并进行整合,PTN-NTS组成的二级神经元传入通路可能是面口部穴位调节内脏功能活动的重要途径。

Objective To investigate the regulation of electroacupuncture （EA） at orofacial acupoints on visceral sensation and its pathway.Methods Thirty adult Sprague-Dawley rats were divided randomly into normal saline,visceral pain,Sibai acupoints,Jiache acupoints and Yangbai acupoints 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 I.p.injection of acetic acid produced characteristic writhing movement,which was composed of the contraction of the flank muscles together with inward movements of the hindlimb.Pretreatment of EA at Sibai or Jiache acupoints induced c-fos expression in the PTN and reduced abdominal contractions and c-fos expression in the NTS elicited by acetic acid.However,pretreatment of EA at Yangbai acupoints did not.Conclusions （1）EA at orofacial acupoints have significant analgesia on visceral pain rats,and there is acupoints specificity in the effect,which is associated with nerve innervation of acupoints.（2） NTS may be an important supraspinal structure in the somato-visceral processing and there exists orofacial areas-PTN-NTS secondary neural pathway,which may be involved in the analgesia of EA at orofacial acupoints on visceral pain.