Abstract: AIM:To observe the modulatory action of diethylstilbestrol on TNBS-induced colitis .METHODS: After the rats with colitis induced by TNBS were injected intramuscularly with diethylstilbestrol at doses of 50, 100, 150, 200 ^μg·kg ^-1 respectively, they were killed on day 7 postdose .Then determined colon weight, ulcerative erea, thymus weight, spleen weight, MPO aetivity and observed microstructure with HE staining .RESULTS:Diethylstil- bestrol at the dose of 50 ^μg·kg^-1 deteriorate the inflam- mation, but diethylstilbestrol of 100 ^μg·kg ^-1 ameliorate the disease .Interestingly, diethylstilbestrol increased the mortality rate of the rats though it relieved inflammatory response significantly at the doses of 150 and 200 ^μg·kg ^-1 .CONCLUSIOND:Diethylstilbestrol exhibits curative effect at the proper dose, while much lower or higher level of diethylstibestrol can not be used to treat the colitis .

Key words: diethylstilbestrol , colitis , cytokine, 2, 4, 6-trinitrobenzen sulfunic acid , self-immunity