(A-G) GPR81−/− and GPR81+/+ littermate control (WT) mice were treated with 2.5% DSS in drinking water for 6 days and at day 9 the colons of mice were analyzed for inflammation. (A, B) Changes in body weight and colon length (day 9) of WT and GPR81−/− mice. (C) Myeloperoxidase activity in colon. (D) Mice were fed with FITC-dextran on day 9, and 4 h later FITC-dextran was quantified in serum (n=5). (E) Representative colonic tissue sections of DSS-treated WT and GPR81−/− mice (Hematoxylin and eosin staining with original magnification, 100X). (F) Histopathological score (inflammation + epithelial damage) of colons was graded following analysis of H&E-stained cross sections of colons of DSS-treated WT and GPR81−/− mice. (G) Excised colon samples were cultured for 2 days ex vivo, and the secreted IL-6, TNF-α, IL-1β, IL-12p40 and IL-10 cytokine levels in the culture supernatants were quantified by ELISA. Data are representative of three separate experiments (n>5). **p<0.01; ***p<0.001. Error bars indicate mean ±SEM.