针刺对偏头痛大鼠三叉神经节和三叉神经脊束尾核A1R/ERK1/2/CGRP通路的影响

Effects of Acupuncture on A1R/ERK1/2/CGRP Pathway in TG and TNC of Rats with Migraine

目的:探讨针刺太冲穴对肝阳上亢型偏头痛模型鼠镇痛作用的可能机制。方法:66只SD大鼠随机分为空白对照组(n=10)、模型组(n=56),以附子汤灌胃加右肩颈部皮下注射硝酸甘油建立肝阳上亢偏头痛模型,其中50只大鼠成模,将成模大鼠随机分为模型组、太冲组、非穴组、太冲+DPCPX(A1R拮抗剂)组和太冲+EGF(ERK1/2激动剂)组,每组10只。太冲组、太冲+DPCPX组及太冲+EGF组针刺双侧太冲穴,非穴组针刺双侧胁下非穴,均留针30 min。观察各组大鼠行为学(耳红持续时间、挠头及爬笼次数)、三叉神经节(TG)和三叉神经脊束尾核(TNC)中A1R、ERK1、ERK2、CGRP的mRNA及蛋白水平。结果:除空白对照组外,其余各组均在注射硝酸甘油后3~4 min出现耳红,持续约3 h消失;与模型组比较,太冲组耳红持续时间较短,差异具有统计学意义(P<0.05),与太冲组比较,非穴组、太冲+DPCPX组及太冲+EGF组耳红持续时间较长,差异具有统计学意义(均P<0.05);针刺前1 h,除空白对照组外,各组挠头、爬笼次数明显增加且各组间差异无统计学意义(均P>0.05);针刺后1 h、2 h,与模型组比较,太冲组挠头、爬笼次数减少,差异具有统计学意义(P<0.05);与太冲组比较,非穴组、太冲+DPCPX组及太冲+EGF组挠头、爬笼次数增加,差异具有统计学意义(均P<0.05)。与空白对照组比较,模型组TG、TNC中ERK1、ERK2、CGRP mRNA和蛋白表达均增加,差异具有统计学意义(均P<0.05),A1Rm RNA和蛋白表达均减少,差异具有统计学意义(均P<0.05);与模型组比较,太冲组大鼠TG、TNC中ERK1、ERK2、CGRP mRNA和蛋白表达均减少,差异具有统计学意义(均P<0.05),A1R mRNA和蛋白表达均增加,差异具有统计学意义(均P<0.05);与太冲组比较,非穴组、太冲+DPCPX组及太冲+EGF组大鼠TG、TNC中ERK1、ERK2、CGRP mRNA和蛋白表达均增加,差异具有统计学意义(均P<0.05),A1R mRNA和蛋白表达均减少,差异具有统计学意义(均P<0.05)。结论:针刺太冲穴治疗偏头痛的可能机制是通过激活TG和TNC的A1R,抑制ERK1/2磷酸化,进而减少CGRP的释放来缓解偏头痛。

Objective:To explore the possible analgesic mechanism of needling Taichong(LR3)in treating migraine with hyperactivity of Liver-Yang in rats.Methods:66 rats were randomly divided into the blank control group(n=10)and the modeling group(n=56).The rat model of migraine with hyperactivity of Liver-Yang was established by administration of Fuzi Decoction and subcutaneous injection of Nitroglycerin.50 rats were successfully modeled and were randomly divided into the model group,the LR3 group,the non-acupoint group,the LR3+DPCPX(A1R antagonist)group and the LR3+EGF(ERK1/2 agonist)group,with 10 rats in each group.The LR3 group,the LR3+DPCPX group and the LR3+EGF group were intervened with needling bilateral LR3,whereas the non-acupoint group was intervened with needling bilateral subcostal non-acupoint,both for 30 min.The behavior of rats,including ear redness duration,times of head scratching and cage climbing were observed;also,mRNA and protein expressions of A1R,ERK1,ERK2 and CGRP in trigeminal ganglion(TG)and trigeminal nucleus caudalis(TNC)were detected in the groups.Results:Except for the rats in the blank control group,the rats in the other groups manifested ear redness 3-4 min after Nitroglycerin injection,which lasted for about 3 hours.Compared with that in the model group,the duration of ear redness was shorter in the LR3 group(P<0.05);compared with that in the LR3 group,the duration of ear redness was longer in the non-acupoint group,the LR3+DPCPX group and the LR3+EGF group(P<0.05).1 h before needling,the times of head scratching and cage climbing were increased in all groups but the blank control group,and there were no significant differences among these groups(P>0.05).The times of head scratching and cage climbing were reduced in the LR3 group compared with those in the blank control group 1 h and 2 h after needling(P<0.05);which were increased in the non-acupoint group,the LR3+DPCPX group and the LR3+EGF group compared with those in the LR3 group(P<0.05).The mRNA and protein expressions of ERK1,ERK2 and CGRP in TG and TNC were remarkably increased(P<0.05),whereas the mRNA and protein expressions of A1R were decreased in the model group compared with those in the blank control group(P<0.05);compared with those in the model group,the mRNA and protein expressions of ERK1,ERK2 and CGRP in TG and TNC were decreased(P<0.05),whereas the mRNA and protein expressions of A1R were increased in the LR3 group(P<0.05).The mRNA and protein expressions of ERK1,ERK2 and CGRP in the TG and TNC were increased(P<0.05),whereas the mRNA and protein expressions of A1R were decreased in the non-acupoint group,the LR3+DPCPX group and the LR3+EGF group(P<0.05).Conclusion:One of the possible mechanisms of needling LR3 in treating migraine is to inhibit ERK1/2 phosphorylation by activating A1R in TG and TNC,thus to reduce the release of CGRP to relieve migraine.