Abstract: The experiment was aimed to establish mouse model of ulcerative colitis(uc) by screening the optimum concentration of dextran sulfate sodium salt(DSS).Thirty BALB/c mice were randomly assigned to control group, 3.5% DSS group and 5% DSS group, ten mice each group.Mice drank water freely for 5 days, the body weights of everyday were recorded, stool was observed and stool occult blood was tested.After the experiment, the changes of TNF-α, MPO, MDA and GSH were tested, and the colon weight/length ratio was calculated.Compared with control group, the activity of MPO and content of MDA in the experiment groups were significantly increased(P<0.05), and content of GSH was significantly decreased(P<0.05).3.5% and 5% DSS both could successfully establish mouse model of ulcerative colitis.Mice in 5% DSS group had poor mental state, such as lethargy, malaise;Mice in 3.5% DSS group were appropriate, the mice mental was good, MPO, MDA and GSH were significantly different compared with control group(P<0.05), but there were no difference compared with 5% DSS group(P>0.05).So 3.5% DSS was more appropriate than 5% DSS to establish mouse model of ulcerative colitis.

Key words: ulcerative colitis(UC); DAI; TNF-α; MPO; MDA; GSH