Experimental Colitis Model Induced by DSS and TNBS in Rats:A Comparative Study / 胃肠病学

ABSTRACT

Background:As the empirical studies on human body are restricted extremely,the establishment and selection of suitable animal models are important for researches on ulcerative colitis( UC ). Aims:To compare the symptoms and colonic pathology of rat models with experimental colitis induced by dextran sulfate sodium( DSS ) and trinitrobenzene sulfonic acid( TNBS),so as to provide a reference for selecting animal models in UC-related studies. Methods:Drinking 4% DSS freely for 7 days or intrarectal administration of single dose 100 mg/kg TNBS-50% ethanol were used to establish experimental colitis model in Sprague-Dawley rats. The disease activity index( DAI)was assessed dynamically during the course of experiment. The whole colon was removed in batches for measurements of colonic damage score and activity of myeloperoxidase(MPO)at different time points. Results:The DAI score reached the peak at the 7th day and the 2nd day in DSS group and TNBS group,respectively,and decreased gradually afterwards. Six and one deaths occurred during the experimental course in DSS and TNBS groups,respectively. In DSS group,the duration of inflammation was short,the colonic injury was moderate and recovered after drug withdrawal. At the 18th day,the colonic damage score and MPO activity was 0. 25 ± 0. 50 and(0. 80 ± 0. 33)U/g,respectively,and no significant differences were seen between DSS group and normal control group. In TNBS group,the duration of inflammation was longer and the colonic injury was more severe. At the 21st day,the colonic damage score and MPO activity was 3. 60 ± 0. 55 and( 1. 60 ± 0. 39 ) U/g, respectively,and chronic inflammation was observed histologically. Conclusions:Both DSS and TNBS can induce experimental colitis model in rats. The course of TNBS-induced colitis model presents a transformation of acute to chronic inflammation,and may be more suitable for treatment-related studies of UC.