【Animal modeling】-Irritable bowel syndrome visceral hypersensitivity model

  Objective: To study various methods of establishing an immature rat model of IBS visceral hypersensitivity, and to evaluate its visceral sensitivity and stability.

  Method: The 2-day-old SD rat puppies were randomly divided into a mother-infant isolation group (group A), an unpredictable mother-infant isolation group (group B) and a blank control group (group C). After successfully establishing the model, observe the rat's general condition and stool condition, and determine the rat's visceral hypersensitivity and persistence through the abdominal wall retraction reflex (AWR) score and the visceral pain threshold. Decided. After the test, rat colon tissue was collected for pathology. Results: There were no significant differences in body weight and colonic histopathology between groups (P\→0.05); compared with groups A and C, the stool count and stool water content of rats in group B increased significantly in group B and group B The AWR scores of the rats were higher than those of the C and A groups, and reached the peak at 9 weeks of age, but at 11 weeks of age, the AWR scores of the A and B rats were previously higher. It becomes below. Within 5-9 weeks, the visceral pain threshold caused by group A and group B was lower than each group.

   Conclusion: Both mother-child separation and unpredictable mother-child separation can simulate the IBS visceral hypersensitivity model, and the unpredictable mother-child separation model is suitable for creating diarrhea-type IBS models. At the same time, the IBS visceral hypersensitivity is time-dependent, and the stable period of the model is mainly from the end of the model to the rats within 9 weeks of age.