动物实验,应激刺激,消化道免疫 z-bo 2020-10-12 286

　　Objective: To observe the effects of unpredictable stress stimulation on the immune system and microbial populations of the gastrointestinal tract by observing the rats 9 days after the stress intervention, and to provide references for the study of chronic stress on gastrointestinal function.

　　Method: 24 SD rats were randomly divided into a blank group and a chronic stress model group. The rats in the model group received unexpected pressure stimulation for 9 consecutive days. After modeling, 5 rats were randomly selected from the normal and model groups, and their stool samples were collected to analyze the gut microbial diversity. Among 12 rats in each group, 4 rats were randomly selected for perfusion fixation, and gastric antrum and colon tissues were collected for morphological observation, and the plasma and adrenal tissues of the remaining 8 rats were harvested to detect corticosterone content.

　　Results: (1) 9 days after the unpredictable stress stimulation, the weight gain of the rats in the model group was significantly lower than that of the rats in the normal group and the adrenal tissue of the model group within 9 days (P = 0.001) . The content of corticosterone was higher than that of the normal group. Compared with rats, it was significantly reduced (P = 0.006); compared with the normal group, the plasma corticosterone content of the model group increased (P = 0.025). (2) After 9 days, the gastric mucosal epithelial cells in the model group were sparser and thinner than the normal group (P = 0.034), and the neutrophils of the gastric mucosa in the model group decreased. This number is lower than the normal group. Compared with the normal group, the number of neutrophils in the colonic mucosa of the model group increased (P = 0.013). 3) After 9 days of chronic unpredictable stress, compared with rats in the normal group, α diversity analysis showed that the types of OTU bacteria in the stool samples of the model group increased significantly. (P = 0.001); Among them, the ratio of Desulfovibrio and Helicobacter pylori in the rat samples of the model group was higher than that of the normal group (P = 0.011, P = 0.047) and the model group. Compared with the normal rat group, the proportion of fungicides was significantly reduced. The difference is statistically significant (P = 0.001).

　　Conclusion: Unpredictable stress stimulation can create a stable rat model of chronic stress. The immunosuppression caused by chronic stress and the imbalance of the intestinal flora of rats occur simultaneously.