Unpredictable Stress Factor On The Mice Model Of Ulcerative Colitis Induced By Dextran Sodium Sulphate In The Injury And Protective Effect Of Melatonin

Objective:To observe the Unpredictable stress on dextran sodium (DSS)-induced ulcerative colitis in mice (UC) of the protective effect of melatonin.Methods:70 BALB/C mice were randomly divided into 7 groups.Normal groups:double distilled water to drink;Modelgroups:DSS modeling;Stress groups:DSS modeling+ stress+ absolute ethanol plus NS(1:9) intraperitoneal injection and empty needle inserted stomach;(D)5-ASA groups:DSS modeling+5-ASA (lOmg) gavage+ absolute ethanol plus NS(1:9) intraperitoneal injection;5-ASA+Stress groups:DSS modeling+1%MT (150.0 mg/kg ip)+ stress+ empty needle inserted stomach;MT+Stress groups:DSS modeling +5-ASA(10mg) gavage+stress+absolute ethanol plus NS(1:9) intraperitoneal injection; MT groups:DSS modeling+1%MT(150.0mg/kg ip)+ empty needle stomach inserted stomach.Free drink with mouse DSS model of UC Solution Methods. DSS began modeling with 3% DSS,7 days to 2% DSS to maintain, to the end of the experiment a total of 14 days. Groups were observed daily disease activity index (DAI). Measured in the experiment after the end of the colon length, tissue injury score (HS), myelopero-xidase (MPO) activity. HS score comes by the light microscope histological changes. Results:The model groups, stress groups,5-ASA Groups,5-ASA+ stress groups, MT groups, MT+ stress groups mice DAI score, HS score and MPO activity in colon tissue compared with normal control group increased (P<0.05).5- ASA group, MT group than the normal control group, the index changes more significantly, with the model group, stress group,5-ASA group+ stress group, MT+stress group decreased (P<0.05). MT group of the index and 5-ASA group showed no significant difference (P>0.05), MT+ stress group, the index and 5-ASA+ stress group, no significant difference(P>0.05), excepting MPO activity。Conclusion:1.Unpredictable stress can make mice increased susceptibility to UC and to increase the DSS colitis injury;2. Melatonin can protect experimental colitis in rats.3.Effect of. melatonin on experimental colitis is not only anti-inflammatory effects are anti-stress.