A Study Of The Effects Of Chronic Restraint Stress On Ulcerative Colitis Induced By Dextran Sulphate Sodium In Mice

Objective : Ulcerative colitis (UC) is a multifactorial disease withunknown pathogenesis and the effects of psychological stress on UC arestill controversial. To elucidate the role of psychological stress in UC, westudied the effects of chronic restraint stress on dextran sulfate sodium(DSS)-induced colitis in mice, and discussed the possible mechanisms.Methods: Sixty-four BALB/C mice were divided into 6 groups:normal mice, mice treated with 2%DSS,4%DSS,restraint stress, restraintstress+2%DSS and restraint stress+4%DSS.Mice in restraint stress,restraint stress+2%DSS and restraint stress+4%DSS were treated withrestraint stress from days 1 to 14.All mice were fed with standard diets.DSS was administered to mice at concentrations 2% and 4% in drinkingwater from days 15 to 21.Mice were killed on days 22.The developmentof colitis were assessed by the disease activity index(DAI),histologicalscores(HS), and colonic mucosal myeloperoxidase(MPO) activity. Thenumber of goblet cells containing mucus was counted.Results: Chronic restraint stress slowed down the increase of bodyweight in mice (P＜0.05).4%DSS significantly increased DAI, MPO, HS(P＜0.05), and decreased the number of goblet cells (P＜0.01). Restraintstress further increased DAI, MPO, HS (P＜0.01) in 4%DSS-inducedcolitis. No change was seen in 2%DSS mice. Restraint stress+2%DSS increased DAI, MPO, HS, and decreased the number of goblet cellscompared with normal controls (P＜0.05).Restraint stress didn't increaseDAI, MPO and HS, but significantly decreased the number of goblet cellscontaining mucus.Conclusion: These results suggest that chronic restraint stressincreased the susceptibility to DSS-induced ulcerative colitis andenhanced intestinal inflammation in it. It was probably caused bydecrease of intestinal goblet cell resulting in dysfunction of intestinalbarrier.