Résumé
Objective To investigate the regulatory actions of Intestines-unblocking, Turbid-purging Recipe (ITR) on colonic 5-hydroxytryptamine (5-HT) and its receptor 5-hydroxytryptamine 3 (5-HT3) in rats with constipation-dominant irritable bowel syndrome (IBS-C), and to explore the therapeutic mechanism of ITR in treating IBS-C. Methods Forty-two male SD rats were randomly divided into 6 groups, namely normal group, model group, western medicine group, high-, middle- and low-dose Chinese medicine groups, 7 rats in each group. IBS-C rat model was established by intragastric administration of ice water. After establishment of the model, western medicine group was given intragastric administration of Cisapride Tablets (at the dosage of 3.6 mg·kg-1·d-1), Chinese medicine groups were given intragastric administration of various dosages of ITR granules (18.5, 9.25, 4.625 g·kg-1·d-1 respectively) , and the model group was given intragastric administration of normal saline, the treatment lasting 14 d. The rats in various groups were given normal feeding and drinking. After treatment, HE staining method was used to observe pathological changes in the intestinal tissue, immunohistochemistry method was used to observe the expression levels of intestinal 5-HT and 5-HT3 receptor. Results Compared with the normal group, the expression level of rat intestinal 5-HT was increased (P < 0.05) and that of 5-HT3 receptor was decreased (P < 0.05) in the model group and the medication groups. Compared with the model group, 5-HT expression level was decreased significantly (P<0.05) and 5-HT3 receptor expression level was increased (P < 0.05) in the medication groups, and the improvement of the middle-dose Chinese medicine group was more obvious (P < 0.05). Conclusion ITR has therapeutic efficacy for IBS-C rats through lowering 5-HT expression and increasing 5-HT3 receptor expression, which results into the improvement of intestinal sensitivity and abnormal dynamic of the rats.