电针对背根神经节持续受压模型大鼠机械痛阈及TRPV1、SP、CGRP表达的影响

Effects of electroacupuncture on TRPV1, SP and CGRP in dorsal root ganglion of dorsal root ganglion chronic compression model rats*

摘要:

目的 观察电针对背根神经节持续受压(Chronic compression of dorsal root ganglion,CCD)模型大鼠机械性刺激缩足反应阈值(Mechanical paw-withdrawl threshold,MPWT)及背根神经节(Dorsal root ganglion,DRG)瞬时受体电位香草酸亚型1(Transient receptor potential vanilloid 1, TRPV1)、P物质(Substance P,SP)、降钙素基因相关肽(Calcitonin gene-related peptide,CGRP)表达的影响。方法 将18只SD大鼠,随机分为假手术组、模型组、电针组,每组6只,电针组取大鼠患侧“足三里”、“昆仑”穴进行治疗,1次/天,共7天。检测各组大鼠不同时间点患侧MPWT,采用免疫荧光法检测大鼠患侧L5 DRG中TRPV1、CGRP、SP阳性细胞表达情况。免疫印迹法检测大鼠患侧L5 DRG中TRPV1、CGRP、SP蛋白表达变化。结果 ①造模后第1天电针治疗前,与假手术组相比,模型组和电针组大鼠MPWT显著降低(P<0.01)；电针治疗后第1、3、5、7天,电针组大鼠患侧MPWT显著高于同期模型组(P<0.01)。②与假手术组相比,模型组大鼠患侧DRG中TRPV1、SP、CGRP阳性细胞数表达均升高(P<0.05)；TRPV1和SP、TRPV1和CGRP阳性细胞共表达数亦升高(P<0.05)；③与模型组相比,电针组大鼠患侧DRG中TRPV1、SP、CGRP表达均降低(P<0.05)；TRPV1和SP、TRPV1和CGRP阳性细胞共表达数降低(P<0.05)；④与假手术组相比,模型组大鼠患侧DRG中TRPV1、CGRP、SP蛋白表达升高(P<0.01)；⑤与模型组相比,经电针干预后,电针组大鼠患侧DRG中TRPV1、CGRP、SP蛋白表达降低(P<0.01)结论 电针治疗可促使MPWT升高,有效抑制CCD大鼠痛觉敏化,其镇痛机制可能与下调DRG中TRPV1、SP和CGRP的表达有关。

Abstract:

【:】 Objective To observe any effect of electroacupuncture on the mechanical paw-withdrawl threshold ( MPWT ) and the expression of transient receptor potential vanilloid 1 ( TRPV1 ), Substance P ( SP ) and Calcitonin gene-related peptide ( CGRP ) in dorsal root ganglion ( DRG ) of rats with chronic compression of dorsal root ganglion ( CCD ). Methods 18 SD rats were randomly divided into sham operation group, model group and electroacupuncture group(n=6). The electroacupuncture group was intervened at Zusanli and Kunlun points on the affected side of the rats, once a day for 7 days. MPWT at different time points on the ipsilateral side of rats in each group was detected. The expression of TRPV1, CGRP and SP positive cells in the ipsilateral DRG of rats was detected by immunofluorescence. Results ①On the first day after modeling, before electroacupuncture intervention, compared with the sham group, the MPWT of the model group and the electroacupuncture group was significantly lower ( P < 0.01); from the first day to the seventh day after electroacupuncture intervention, compared with the model group, the MPWT of rats in the electroacupuncture group was significantly increased (P < 0.01). ②Compared with the sham group, the expression of TRPV1, SP and CGRP positive cells in the dorsal root ganglion of the model group increased (P < 0.05 ). The number of TRPV1/SP and TRPV1/CGRP co-localized positive cells also increased ( P < 0.05 ). ③Compared with the CCD group, the expressions of TRPV1, SP and CGRP in the DRG of the rats in the electroacupuncture group were significantly decreased (P < 0.05 ). The number of TRPV1/SP and TRPV1/CGRP co-localization positive cells decreased (P < 0.05 ). ④Compared with the sham group, the expression of TRPV1, CGRP, and SP proteins in the ipsilateral DRG on the ipsilateral side of the model group rats was increased (P < 0.01).⑤Compared with the CCD group, after electroacupuncture intervention, the expression of TRPV1, CGRP, and SP proteins in the ipsilateral DRG on the ipsilateral side of the electroacupuncture group rats was decreased (P < 0.01).