痛泻要方对肠易激综合征作用机制的实验研究

目的探讨痛泻要方对内脏高敏感性肠易激综合征(IBS)模型大鼠的疗效和作用机制。方法采用结肠慢性刺激法制作内脏高敏感性的IBS大鼠模型。将实验动物分为正常组,模型组,阳性对照(得舒特)组,痛泻要方低、高剂量组。观察各组大鼠肠道内扩张引起腹部抬起和背部拱起的容量阈值和大鼠肠道内不同容量下扩张期间腹壁收缩次数,检测5-羟色胺(5-HT)、P物质(SP)、降钙素基因相关肽(CGRP)水平。结果与模型组相比,各治疗组大鼠行为学和电生理指标均有明显改善;各治疗组模型大鼠5-HT、SP水平明显下降,CGRP水平增加,且有一定的量效关系。结论痛泻药方能降低内脏高敏感性IBS模型大鼠血清5-HT、血浆SP水平,增加CGRP水平,大剂量痛泻药方疗效优于得舒特。痛泻药方的作用机制可能是通过降低模型大鼠血清5-HT、血浆SP水平,减弱背角神经元兴奋性,从而提高内脏痛阈、消除肠道过敏而达到治疗目的。

Mechanism of Tongxieyaofang on irritable bowel syndrome

Objective To study the effect and the mechanism of Tongxieyaofang (TXYF) on rat model of irritable bowel syndrome (IBS). Methods Model rats of IBS which were prepared by chronic stimulation in colon were randomly divided into groups: the normal control group (Group A), the model control group (Group B), the positive control group (Group C), the low dosage of TXYF group (Group D), the high dosage of TXYF group (Group E). Different treatments were given to every groups by ig administration for one month. The capability limens of the sacculus that caused abdomen-uplifting and back-arching and the times of contract of abdomen muscle in rats under different dilatations were observed. The levels of 5-hydroxytryptamine (5-HT), substance P (SP), and calcitonin gene related peptide (CGRP) were evaluated. Results Compared with the Group B, the TXYF could effectively improve the index of the behavior and electrophysiology, it also could lower the levels of 5-HT and SP, and increase the levels of CGRP of rat model of IBS with certain dose-effect relationship. Conclusion TXYF could lower the levels of 5-HT in serum and SP in plasma, and increase CGRP level of model rats of IBS, especially in high dosage. The mechanism of TXYF may be increasing the pain threshold of bowel, eliminating hypersusceptibility of bowel, and decreasing excitability of nerve cells by decreasing the 5-HT and SP levels in IBS rats.