针刺合募配穴对肠易激综合征大鼠结肠内脏高敏相关因子的影响

Electroacupuncture Relieves Visceral Hypersensitivity by Down-regulating Mast Cell Number,PAR-2/TRPV 1 Signaling,etc. in Colonic Tissue of Rats with Irritable Bowel Syndrome

目的:观察针刺合募配穴对肠易激综合征(IBS)大鼠结肠组织中类胰蛋白酶(Try)、蛋白酶活化受体2(PAR-2)、瞬时受体电位香草酸亚型1(TRPV 1)、P物质(SP)和降钙素基因相关肽(CGRP)表达的影响,探讨针刺合募配穴治疗IBS的机制。方法:雄性SD大鼠随机分为空白组、模型组、药物组和合募针刺组,每组10只。采用慢性应激结合束缚方法建立IBS大鼠模型。合募针刺组针刺"上巨虚""天枢"穴,30min/d,药物组予匹维溴胺(15mg·kg^(-1)·d^(-1))灌胃,均治疗14d。观察大鼠体质量,检测大鼠结直肠扩张(CRD)容量阈值和腹壁回撤反射(AWR)评分,甲苯胺兰染色法观察结肠组织肥大细胞(MC)计数,免疫组化法检测结肠组织Try表达水平,Western blot法检测结肠组织中PAR-2、TRVP 1、SP、CGRP的表达水平。结果:与空白组相比,模型组大鼠体质量显著降低(P<0.01),在CRD检测中腹部抬高和臀部抬高容量阈值明显降低(P<0.01),AWR评分、结肠组织MC计数及Try、PAR-2、TRVP 1、SP、CGRP表达水平均显著升高(P<0.01)。与模型组比较,药物组、合募针刺组大鼠体质量显著升高(P<0.01,P<0.05),在CRD检测中腹部抬高和臀部抬高容量阈值明显升高(P<0.05,P<0.01),AWR评分、结肠组织MC计数及Try、PAR-2、TRVP 1、SP、CGRP表达水平均显著降低(P<0.01)。合募针刺组结肠组织PAR-2、TRVP 1、SP、CGRP表达水平较药物组降低更显著(P<0.05)。结论:针刺合募配穴可降低IBS大鼠结肠组织中Try、PAR-2、TRVP 1、SP和CGRP的表达水平,减轻IBS的高敏反应。

Objective To observe the effect of electroacupuncture（EA）stimulation of ＂Shangjuxu＂（ST 37,Lower Confluent point） and ＂Tianshu＂（ST 25,Front-Mu point）on visceral pain and expression of colonic tryptase（Try）,proteinase-activated receptor 2（PAR-2）,transient receptor potential channel vanilloid subfamily member 1（TPRV 1）,substance P（SP）and calcitonin gene-related peptide（CGRP）in rats with irritable bowel syndrome（IBS）,so as to explore its mechanisms underlying improvement of IBS.Methods Forty male Sprague Dawley rats were equally randomized into normal control（control）,model,medication and EA groups（n=10 in each）.The IBS model was established by chronic acute combining stress（CACS,water deprivation,fasting,tail clamping,forced swimming in ice water,restraint,etc.）for 21 days.Rats of the medication group were treated by gavage of Pinaverium Bromide（1 mg/mL,15 mg/kg）,once daily for 14 d.EA（10 Hz/50 Hz,0.2-0.3 mA）was applied to bilateral ST 37 and ST 25 for 30 min,once daily for 14 d.The muscular withdrawal reflex（AWR）of both abdomen and buttock was detected by colorectal distension（CRD）with a water-filled balloon for examining the visceral hypersensitivity.The number of mast cells in the colonic tissue was counted after toluidine blue stain.The immunoactivity of colonic Try was determined by immunochemistry and the expression of colonic PAR-2,TRVP 1,SP and CGRP proteins detected by Western blot.Results After modeling,the body weight was significantly decreased in IBS rats of the model,medication and EA groups compared with their own individual pre-treatment and with the control group（P〈0.01）,and markedly higher in both medication and EA groups than in the model group（P〈0.05,P〈0.01）.The intra-colonic volume thresholds for inducing abdominal and hip AWR were significantly lower in the model group than in the normal control group（P〈0.01）,and obviously higher in both medication and EA groups than in the model group（P〈0.05,P〈0.01）.The AWR scores of intra-colorectal balloon at volumes of 0.5,1.0 and 1.5 mL of water were significantly higher in the model group than in the control group（P〈0.01）,and considerably lower in the EA and medication groups than in the model group（P〈0.01）.The number of colonic MC and the expression levels of colonic Try,PAR-2,TRPV 1,SP and CGRP proteins were significantly higher in the model group than in the control group（P〈0.01）,and obviously decreased in both medication and EA groups relevant to the model group（P〈0.01）.Comparison between the medication and EA groups showed that the decreased expression levels of colonic PAR-2,TRPV 1,SP and CGRP proteins were significantly lower in the EA group than in the medication group（P〈0.05）,but no significant differences were found between the two groups in intracolonic volumes for inducing AWR,AWR scores,body weight,and colonic MC number and Try immunoactivity levels（P〉0.05）.Conclusion EA of ST 37 and ST 25 can relieve visceral hypersensitivity in IBS rats,which may be associated with its effects in down-regulating the number of MC and the expression of PAR-2,TRVP 1,SP,CGRP and Try proteins in the colonic tissue.