电针“扶突”等穴对颈部切口痛大鼠颈段脊髓5-羟色胺1A、5-羟色胺2A受体mRNA表达的影响

目的:观察电针双侧"扶突"等穴对甲状腺区切口痛大鼠颈段脊髓中5-羟色胺(HT)受体(R)亚型5-HT 1AR和5-HT 2AR mRNA及蛋白表达的影响,探讨电针缓解颈部切口痛的可能机制。方法:Wistar雄性大鼠随机分为正常组、模型组、扶突组、合谷-内关组、足三里-阳陵泉颈段组、足三里-阳陵泉腰段组,每组8只。沿大鼠颈中线做长约1.5cm的纵行切口,制作切口痛模型。分别电针双侧"扶突""合谷"-"内关""足三里"-"阳陵泉"穴,各30min。用辐射热测大鼠切口部位热痛阈;用荧光定量Real-time PCR和免疫印迹(Western blot)方法检测颈段(C1-C4)、腰段(L1-L3)脊髓5-HT 1A和5-HT 2A受体亚型mRNA和蛋白的表达水平变化。结果:与颈部切口术前比较,各组的热辐射躲避潜伏期明显缩短(P<0.05);电针"扶突"穴或"合谷"-"内关"穴后,与本组术后比较其躲避潜伏期显著延长(P<0.05);电针"足三里"-"阳陵泉"与本组术后比较差异无统计学意义(P>0.05)。与正常组比较,模型组颈段脊髓中5-HT 1AR mRNA的表达明显升高(P<0.05),5-HT 2AR mRNA和蛋白的表达均明显上调(P<0.05);与模型组比较,扶突组和合谷-内关组脊髓中5-HT 1AR的mRNA表达水平均明显下降(P<0.05),5-HT 2AR的mRNA和蛋白的表达水平均明显上调(P<0.05),足三里-阳陵泉组5-HT 1AR和5-HT 2AR的mRNA表达水平与模型组比较差异均无统计学意义(P>0.05)。结论:电针"扶突"和"合谷"-"内关"穴可缓解大鼠颈部急性切口痛,该作用可能与其下调颈段脊髓中5-HT 1AR mRNA表达、上调5-HT 2AR mRNA和蛋白的表达水平相关。

Effects of electroacupuncture at "Futu" (LI 18), etc. on expression of spinal 5-HT 1 AR mRNA, 5-HT 2 AR mRNA and protein in rats with neck incision pain

Objective To observe the effect of electroacupuncture(EA) at bilateral "Futu"(LI18),etc.on the expression of 5-HT1A receptor(R) mRNA,5-HT2AR mRNA and protein in the spinal cord of rats with neck incision pain,so as to explore its underlying mechanism in relieving incision pain.Methods A total of 48 Wistar rats were randomly divided into control,model(incision pain),Futu(LI18),Hegu(LI4)-Neiguan(PC6,LI4-PC6),Zusanli(ST36)-Yanglingquan(GB34) cervical cord(ST36-GB34 C) and lumbar cord(ST36-GB34 L) groups.A 1.5cm longitudinal incision was made in the middle of the neck under Isoflurane inhalation anesthesia.Pain threshold(PT) was measured using radiant heat.EA(1-2mA,2Hz/15Hz) was applied to bilateral LI18,LI4-PC6,ST36-GB 34 for 30min.The expression of 5-HT1AR mRNA,5-HT2AR mRNA and protein in the cervical spinal cord(C1-C4) tissue,and 5-HT1AR mRNA and 5-HT2AR mRNA in the lumbar cord(L1-L3) were detected with Real-time PCR and Western blot analysis,respectively.Results After the operation,the thermal PT was shortened obviously in comparison with pre-operation(P<0.05).Compared with post-operation,the PT values were increased markedly in the LI18 group and LI4-PC 6 group(P<0.05),rather than in the ST36-GB 34 group(P>0.05).The expression levels of 5-HT1AR mRNA,5-HT2AR mRNA and 5-HT2AR protein in the cervical cord of the model group were increased significantly compared with those of the control group(P<0.05).In comparison with the model group,the expression level of 5-HT1AR mRNA was down-regulated considerably in the LI18 and LI4-PC 6 groups(P<0.05),and those of spinal 5-HT2AR mRNA and protein were up-regulated significantly in the LI18 and LI4-PC 6 groups(P<0.05).No significant changes were found in the expression of 5-HT1AR mRNA and 5-HT2AR mRNA in the ST36-GB 34 C group in comparison with the model group(P>0.05).The expression levels of 5-HT1AR mRNA and 5-HT2AR mRNA in the ST36-GB34 L group were significantly lower than those of the ST36-GB 34 C group(P<0.05).Conclusion EA of LI18 and LI4-PC 6 can significantly suppress pain reaction of neck incision in the rat,which is closely associated with its effects in down-regulating the expression of 5-HT1AR mRNA and in up-regulating 5-HT2AR mRNA and 5-HT2AR protein in the cervical spinal cord.