大鼠消化道免疫,微生物菌群 z-bo 2020-11-27 364

　　Objective To analyze the effects of unpredictable stress stimulation on the immune system and microbial populations of the gastrointestinal tract by observing the rats after 9 days of unpredictable stress stimulation intervention, so as 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 stress stimulation for 9 consecutive days. After modeling, 5 rats in the normal group and model group were randomly selected, and their stool samples were collected for analysis of intestinal microbial diversity. Of the 12 rats in each group, 4 rats were randomly selected for perfusion fixation, and gastric antrum and colon tissues were taken for morphological observation; the plasma and adrenal tissues of the remaining 8 rats were taken to detect the content of corticosterone.

　　Results (1) After 9 days of unpredictable stress stimulation, the weight gain of rats in the model group was significantly lower than that in the normal group (P=0.001). The content of corticosterone in the adrenal tissue of the model group was comparable to that of the normal group. The ratio was significantly lower (P=0.006); the plasma corticosterone content in the model group increased compared with the normal group (P=0.025). (2) After 9 days, the gastric mucosal epithelial cells of the model group were sparser than the normal group, and their thickness was reduced compared with the normal group (P=0.034); the gastric mucosal lamina propria neutrophils of the model group The number decreased compared with the normal group (P=0.016); the number of neutrophils in the colon mucosa of the model group increased compared with the normal group (P=0.013). 3) After 9 days of chronic unpredictable stress, the Alpha diversity analysis showed that the bacterial species in the OTU of the fecal samples of the model group were significantly increased compared with the normal group of rats (P=0.001); among them, the desulfurization in the model group was desulfurized. The proportions of Vibrioaceae and Helicobacteraceae were increased compared with the normal group of rats (P = 0.011, P = 0.047); the proportion of Bacteroides in the model group's rat samples was significantly reduced compared with the normal group of rats , The difference is extremely statistically significant (P=0.001).

　　Conclusion 9d unpredictable stress stimulation can create a stable chronic stress rat model. The immunosuppression caused by chronic stress is accompanied by the imbalance of the intestinal microflora of rats.