Mechanicm Research On Yiji Capsule For Treatment Of Diarrhea-predominant Irritable Bowel Syndrome Rat Model

Objective Investigate the change of 5-Hydroxytryptamine(5-HT) and the 5-Hydroxytryptamine3 recept(5-HT₃R) in this model,and explore the pathogenesis of Irritable Bowel Syndrome(IBS) and the mechanism of Yiji Capsule(YC) for treatment of IBS.Methods Chemical stimulation of colonic combined with restraint stress to preparae D-IBS rat model.48 rats were randomly devided into six groups:nomal group,untreatedgroup,Dicetel-treated group,high,medium,low dose of YC treated group.Each group received 0.9%Nacl,0.9%Nacl,Dicetel,high,medium,low dose of YC. Observe threshold of the capacity of abdominal withdrawal reflex caused by colorectal balloon distension(CRD) in rat.Immunohistochemical method was used to determine the expressions of 5-HT and 5-HT₃R in colonic mucosa of D-IBS rats.Results1.Compare the threshold of the capacity between each group.There were significant differences on group 1 and group 2(P＜0.01).Group 3,4,5,6 compared separately with group 1,there was no significant difference(P＞0.05).Group 3,4,5,6 compared separately with group 2,we found significant differences(P＜0.01). Group 4,5,6 compared separately with group 3,we did not find any significant difference(P＞0.05).2.Compare the average optical density(OD)of 5-HT positive granules in colonic mucosa of rats.Group 2,3,4,5,6 compared separately with group 1,there were significant differences(P＜0.01) 3, 4,5,6 compared separately with group 2,there were significant differences(P＜0.01).4,5,6 compared separately with group 3, there was no significant difference(P＞0.05).3.Compare the average optical density(OD)of 5-HT₃R positive granules in colonic mucosa of rats.There were significant differences on group 1 and group 2(P＜0.01).Group 3,4,5,6 compared separately with group 1,there was no significant difference(P＞0.05).Group 3,4,5,6 compared separately with group 2,we found significant differences(P＜0.01 ).Group 4,5,6 compared separately with group 3,we did not find any significant difference(P＞0.05 ).Conclusions1.The expression of 5-HT positive tissue in muscularis mucosa, submucosa layer was significantly higher in D-IBS rat colon. 5-HT is an important biological factor causing D-IBS.The expression of 5-HT₃R positive tissue in muscular layer was significantly higher in D-IBS rat colon.2.YC can significantly increased capacity threshold when abdominal withdrawal reflex.It reveal that it can reduce the D-IBS visceral hypersensitivity.3.YC can depress the expression of 5-HT,5-HT₃R in D-IBS rat colon.The imaginable mechanism of YC is to reduce visceral hypersensitivity by depressing the expression of 5-HT,5-HT₃R. There is a clear dose-response relationship.Larger doses have a more obvious effect...