动物造模 z-bio 2022-10-20 348

　　Objective To establish a mouse model of ulcerative colitis with dextran sulfate sodium (DSS) and 2,4,6-trinitrobenzene sulfonic acid (TNBS), and compare the clinical symptoms, pathological damage of colon tissue and composition of colonic flora.

　　Methods Thirty C57BL/6 male mice were randomly divided into control group, DSS group and TNBS group. The molding period is 7 days. The clinical symptoms, including body weight and fecal occult blood, were monitored daily. At the end of modeling, the colon was taken for histopathological diagnosis, and 16S rDNA sequencing technology was used to detect the flora composition of colon contents.

　　Results The clinical results showed that the DSS group began to excrete soft stool from the third day, and the fecal occult blood was positive on the fifth day, with weight loss; The weight of TNBS group decreased on the second day, soft stool and loose stool were excreted 4 days before modeling, and fecal occult blood was positive. The autopsy showed that the weight of colon in both model groups increased, and only in DSS group, the colon became significantly shorter. Histopathologically, the inherent structure of the ulcer site of colon in DSS group was destroyed and the adjacent crypt expanded, while the crypt structure remained and crypt cells proliferated in TNBS group. The characteristics of colonic flora disorder in the two model groups were different. Compared with the control group, the abundance of Firmicutes and Cyanobacteria had no significant change in DSS group but increased in TNBS group (P<0.05); The abundance of acid bacilli had no significant change in DSS group, but decreased significantly in TNBS group (P<0.05); The abundance of Actinomycetes and Lactobacillus decreased in DSS group (P<0.05), and there was no significant change in TNBS group; The abundance of Bacteroides increased in DSS group and decreased significantly in TNBS group (P<0.05).

　　Conclusion The UC model induced by ethanol from DSS and TNBS has its own characteristics as well as common features in clinical symptoms, pathological characteristics of colon tissue and intestinal flora structure. The results can provide a theoretical reference for the selection of animal models.