基于NF-κB/AHR通路探讨电针“足三里”和“内关”对肠易激综合征大鼠内脏高敏感的调节机制

Mechanism of Electroacupuncture at Zusanli and Neiguan Points Regulating Visceral Hypersensitivity in Rats with Irritable Bowel Syndrome Based on the Nuclear Factor-kappa B/Aryl Hydrocarbon Receptor Signaling Pathway

目的 观察电针“足三里”和“内关”穴对肠易激综合征(irritable bowel syndrome, IBS)大鼠内脏高敏感的调节机制。方法 将40只新生SD大鼠随机分为模型制备组(n=32)和空白组(n=8),采用“母婴分离结合醋酸灌肠”复制内脏高敏感大鼠模型,将模型复制成功的内脏高敏感大鼠随机分为模型组、假刺激组、电针组,每组8只。假刺激组大鼠仅电刺激非经非穴部位,空白组及模型组大鼠仅抓取,不做其他干预;电针组大鼠给予电针同侧足三里和内关穴,每次30 min,隔日1次,共4周。观察各组大鼠一般情况,体质量,粪便性状评分,内脏痛阈值,血清白细胞介素-17A(interleukin-17A,IL-17A)水平,结肠组织中芳香烃受体(aryl hydrocarbon receptor, AHR)、细胞色素P1(cytochrome P1,CYP1)、核因子-κB(nuclear factor-κB,NF-κB) P65蛋白表达水平。结果 与空白组比较,模型组大鼠粪便性状评分显著增加(P<0.05),体质量显著下降(P<0.05),内脏痛阈值显著降低(P<0.05),血清IL-17A水平显著升高(P<0.05),结肠组织AhR、CYP1、NF-κB P65蛋白表达水平均显著降低(P<0.05);与模型组比较,电针组大鼠粪便性状评分显著减少(P<0.05),体质量显著增加(P<0.05),内脏痛阈值显著增加(P<0.05),血清IL-17A水平显著降低(P<0.05),结肠组织AHR、CYP1、NF-κB P65蛋白表达水平显著上升(P<0.05)。结论 电针“足三里”和“内关”穴能降低IBS大鼠的内脏高敏感,其作用机制可能通过激活NF-κB/AHR通路,上调AHR、CYP1、NF-κB P65蛋白的表达而实现的。

Objective To investigate the mechanism of electroacupuncture at Zusanli and Neiguan points regulating visceral hypersensitivity in rats with irritable bowel syndrome(IBS).Methods A total of 40 neonatal Sprague-Dawley rats were randomly divided into model preparation group with 32 rats and blank group with 8 rats.Maternal separation and enema with acetic acid were performed to establish a rat model of visceral hypersensitivity,and after successful modeling,the rats with visceral hypersensitivity were randomly divided into model group,sham-stimulation group,and electroacupuncture group,with 8 rats in each group.The rats in the sham-stimulation group were given electroacupuncture at sham acupoints,those in the blank group and model group were only grabbed without further intervention,and those in the electroacupuncture group were given electroacupuncture at Zusanli and Neiguan points at the same time,30 minutes each time,once every other day for 4 weeks.These groups were observed in terms of general status,body weight,Bristol Stool Scale score,visceral pain threshold,serum level of interleukin-17A(IL-17A),and protein expression levels of aryl hydrocarbon receptor(AHR),cytochrome P1(CYP1),and nuclear factor-kappa B(NF-κB)P65 in colon tissue.Results Compared with the blank group,the model group had a significant increase in Bristol Stool Scale score(P<0.05),significant reductions in body weight and visceral pain threshold(P<0.05),a significant increase in the serum level of IL-17A(P<0.05),and significant reductions in the protein expression levels of AHR,CYP1,and NF-κB P65 in colon tissue(P<0.05).Compared with the model group,the electroacupuncture group had a significant reduction in Bristol Stool Scale score(P<0.05),significant increases in body weight and visceral pain threshold(P<0.05),a significant reduction in the serum level of IL-17A(P<0.05),and significant increases in the protein expression levels of AHR,CYP1,and NF-κB P65 in colon tissue(P<0.05).Conclusion Electroacupuncture at Zusanli and Neiguan points can reduce visceral hypersensitivity in IBS rats,possibly by activating the NF-κB/AHR pathway and up regulating the protein expression levels of NF-κB P65,AHR,and CYP1.