【Animal Modeling】-Comparative Study on Visceral Hypersensitivity Models Induced by Combined Method

  Objective To observe the effect of maternal-infant separation combined with mechanical stimulation and drug combined with chronic stress on the visceral hypersensitivity model of irritable bowel syndrome, and to explore the advantages and disadvantages of the above two methods.

  Methods SD young and adult rats were randomly divided into mother-infant separation combined with mechanical stimulation group (CRD group) and blank control group (CRD control group), drug combined with chronic stress group (CUMS group) and blank control group (CUMS control group) ), after the model was established, the general condition and defecation of the rats were observed, the abdominal wall withdrawal reflex (AWR) and the visceral pain threshold were used to evaluate the visceral sensitivity of the rats, the plus maze test and the open field test were used to evaluate the anxiety and depression state of the rats. After that, the distal colon of the rat was taken for pathological observation.

  Results Compared with the corresponding control group, the two model groups had higher AWR score, lower visceral pain threshold, and higher fecal water content. Among them, the IBS visceral hypersensitivity rats in the drug combined with CUMS group had shorter open-arm residence time in the plus maze, and the total distance and center residence time of the open field experiment were reduced.

  Conclusion The models induced by the two modeling methods have high visceral sensitivity of IBS and changes in feces, which can better simulate the clinical symptoms of IBS, and tend to be diarrhea-type IBS. Drugs combined with CUMS can better replicate the emotional function of IBS. obstacle.