[Animal modeling] Preparation of a mouse model of diarrhea predominant irritable bowel syndrome induced by acetic acid combined with restraint stress

  Objective To establish a mouse model of diarrhea predominant irritable bowel syndrome (IBS) by rectal perfusion with 3% acetic acid combined with restraint stress, and evaluate the feasibility of the model.

  Methods Forty five male C57BL/6J mice were divided into healthy control group (group C), 3% acetic acid group (group A) and 3% acetic acid+restraint group (group A+R). Compare the weight change and survival of mice in each group before and after intervention, as well as the fecal water content, total intestinal transit time and visceral pain threshold after intervention, and compare the advantages and disadvantages of the two modeling methods. Observe the pathological changes of colon in group C and group A+R, evaluate the intestinal mucosal integrity of mice by FD4 penetration test, and detect serum 5-HT and TNF by ELISA- α The expression of 5-HTR3A in colon tissue was detected by immunohistochemistry, and the pathological change characteristics of this modeling method were clarified.

  Results Compared with group C, visceral pain threshold and fecal water content in group A+R were significantly higher (P<0.001); The total intestinal transit time was significantly shortened (P<0.05), while the visceral pain threshold and fecal water content in group A were also significantly reduced (P<0.05), but="" the="" total="" intestinal="" transit="" time="" had="" only="" a="" trend="" of="" with="" no="" significant="" difference="" p="">0.05). In group A+R, the content of FD4 in plasma increased significantly (P<0.001), 5-HT and TNF in serum- α The content of 5-HTR3A was significantly increased (P<0.05), and the expression of 5-HTR3A in colon tissue was also significantly increased (P<0.001).

  Conclusion Compared with 3% acetic acid enema, 3% acetic acid enema combined with restraint stress can better simulate the local symptoms and pathological changes of IBS-D patients.