痛泻要方对IBS内脏高敏性大鼠结肠组织5-HT_4受体mRNA与c-fos mRNA表达的影响

Effect of Tongxie Yaofang on expression of 5-HT_4 receptor mRNA and c-fos mRNA on colon tissue of IBS visceral hypersensitivity rats

目的:研究痛泻要方对肠易激综合征(IBS)大鼠内脏高敏性外周机制的作用。方法:于乳鼠第8-21天以血管成形术球囊/儿童导尿管插入直肠,并向球囊注水以扩张肠道刺激,2次/d,每次持续1min制备IBS内脏高敏性大鼠模型。分别于直肠扩张刺激停止后2周及4周后进行肠道敏感性评估筛选成模大鼠。大鼠出生第12周,IBS内脏高敏性大鼠分别灌胃痛泻要方2.03g/kg,给药2周。第14周分别取各组大鼠结肠组织进行组织病理学观察;以RT-PCR和免疫组化染色法分析结肠组织中5-羟色胺4受体(5-HT4)mRNA、c-fos mRNA及胃肠激素中生长抑素(SS)、血管活性肠肽(VIP)蛋白的表达变化。结果:经乳鼠结肠刺激方法复制内脏高敏性模型后,肠道敏感性有不同程度增强,然而结肠组织病理学无明显变化,结肠中5-HT4 mRNA表达降低,c-fos mRNA及SS、VIP表达增强,经痛泻要方干预后,肠道敏感性明显降低,5-HT4受体mRNA表达增强,c-fos mRNA及SS、VIP表达均明显降低(P<0.01)。结论:痛泻要方可通过调控外周肠神经丛传入神经元敏感性而发挥抑制内脏高敏性作用。

Objective： To study the effect of Tongxie Yaofang on the periphery mechanism of visceral hypersensitivity on IBS rats. Methods： The angioplasty balloon/pediatric catheter was inserted into rats＇ rectum, and the water was infused in the balloon to expand intestinal on the day 8 to day 2l of suckling rats, lmin/2 times/d, to make IBS model of visceral hypersensitivity rats. At 2 weeks and 4 weeks after rectal distention stimulation, we would choose the successful rat models by assessing bowel sensitivity. From 12 weeks rats born, IBS visceral hypersensitivity rats were ig Tongxie Yaofang at the dosage of 2.03g/kg for 2 weeks. At 14 weeks, the colon tissues of rats in each group were taken out for histopathological observation. Analyze changes of expression of 5-HT4 receptor mRNA and c-fos mRNA by RT-PCR, and expression of SS and VIP protein by immunohistochemistry staining methods. Results： IBS model of visceral hypersensitivity was established by suckling mice colon irritation, sensitivity of the bowel was increased in different degrees, but colonic histopathology did not change significantly. The expression of 5-HT4 receptor mRNA in colon was reduced, the expressions of c-fos mRNA and the expression of SS and VIP were enhanced. After intervened by Tongxie Yaofang, the bowel sensitivity was decreased obviously, the expression of 5-HT4 receptor mRNA was increased, the expression of c-fos mRNA and the expressions of SS and VIP were decreased （P〈0.01）. Conclusion： Tongxie Yaofang can inhibit visceral hypersensitivity by regulating the sensitivity of afferent neuron on the peripheral intestinal nerve plexus.