[Animal modeling] Comparative study on visceral hypersensitivity model induced by combined method

  Objective To observe the effect of visceral hypersensitivity model of irritable bowel syndrome established by maternal infant separation combined with mechanical stimulation and drug combined with chronic stress, and discuss the advantages and disadvantages of the two methods.

  Methods SD young rats and adult rats were randomly divided into mother infant separation combined with mechanical stimulation group (CRD group), blank control group (CRD group), drug combined chronic stress group (CUMS group) and blank control group (CUMS group), The anxiety and depression state of rats were evaluated by cross maze test and open field test. After the above evaluation, the distal colon of rats was taken for pathological observation.

  Results Compared with the corresponding control group, the AWR score of rats in the two model groups increased, the visceral pain threshold decreased, and the fecal water content increased. Among them, in the drug combined with CUMS group, the open arm dwell time of the cross maze of IBS visceral hypersensitive rats was shortened, and the total distance and center dwell time of open field experiment activities were reduced.

  Conclusion Both the models induced by the two modeling methods showed visceral hypersensitivity and fecal changes, which could better simulate the clinical symptoms of IBS, and were more inclined to diarrhea type IBS; Drugs combined with CUMS can better reproduce the emotional dysfunction of IBS.