直肠内脱垂患者直肠顺应性变化与肠黏膜中TRPV1、5-HT表达的关系

Relationship of TRPV1/5-HT expression in intestinal mucosa and rectal compliance in patients with internal rectal prolapse

目的探讨直肠内脱垂(internal rectal prolapse,IRP)患者直肠顺应性改变与TRPV1、5-HT在直肠黏膜层表达的关系。方法选择临床诊断IRP的患者20例及对照组20例先进行肛管直肠测压,然后行结肠镜检查,在齿状线上方4 cm处下段直肠取黏膜活检,行TRPV1和5-HT免疫组化染色,采用图像分析法分析免疫反应阳性情况。结果与对照组比较,IRP组初始感觉容积明显增高(Z=-3.710,P<0.01),最大感觉耐受容积明显降低(Z=-5.181,P<0.01),直肠顺应性明显降低;对照组黏膜层仅有少量TRPV1表达,IRP组直肠黏膜腺体可见大量TRPV1阳性染色,与对照组相比,IRP组直肠黏膜层TRPV1的表达显著增强(Z=-5.085,P<0.01);对照组黏膜层5-HT免疫阳性染色很少,而IRP组黏膜层腺体细胞内5-HT表达量显著升高(Z=-4.734,P<0.01)。结论 IRP患者直肠顺应性明显低于对照组,与直肠黏膜层TRPV1和5-HT免疫反应阳性显著增强导致直肠高敏感有关,可能是IRP患者肛门坠胀、便意频繁等排便功能障碍的机制之一。

Objective To investigated the relationship of expression changes of transient receptor potential vanilloid 1（TRPV1） and 5-hydroxytryptamine（5-HT） in rectal mucosa and rectal compliance in the patients with internal rectal prolapse（IRP）.Methods A total of 20 out-patients who were diagnosed as IRP in our department and 20 sex-and age-matched healthy individuals for physical examination from October to December 2012 were enrolled in this study.They received colonoscopy after anorectal manometry.Immunohistochemical assay for TRPV1 and 5-HT was carried out in the mucosal samples from the lower rectum at 4 cm above the dentate line.Results The initial sensation volume was significantly higher in IRP group than in normal control（Z=-3.710,P0.01）,but the largest feeling tolerance volume was obviously lower in IRP group（Z=-5.181,P0.01）.The rectal compliance was significantly lower in the IRP group than in normal control.TRPV1 was extensively expressed in the rectal mucosa of IRPs when compared in that of control（Z=-5.085,P 0.01）.Similar expression was found in 5-HT in the rectal mucosa（Z=-4.734,P 0.01）.Conclusion Rectal compliance in patients with IRP is significantly lower than normal control,which might be related with the significantly enhanced expression of TRPV1 and 5-HT in rectal mucosa which causes rectal hypersensitivity.It is may be one of the mechanisms of bowel dysfunction as anal bulge and frequent defecation in patients with internal rectal prolapse.