INTESTINAL PERMEABILITY AND CONTRACTILITY IN MURINE COLITIS

WE developed an in vitro organ bath method to measure permeability and contractility simultaneously in murine intestinal segments, To invest igate whether permeability and contractility are correlated and influe nced by mucosal damage owing to inflammation, BALB/c mice were exposed to a 10% dextran sulphate sodium (DSS) solution for 8 days to induce colitis. The effect of pharmacologically induced smooth muscle relaxat ion and contraction on permeability was tested in vitro, Regional perm eability differences were observed in both control and 10% DSS-treated cilice, Distal colon segments were less permeable to H-3-mannitol and C-14-PEG 400 molecules compared with proximal colon and ileum. Intest inal permeability in control vs. 10% DSS mice was not altered, althoug h histologic inflammation score and IFN-gamma pro-inflammatory cytokin e levels were significantly increased in proximal and distal colon. IL -1 beta levels were enhanced in these proximal and distal segments, bu t not significantly different from controls. Any effect of pharmacolog ically induced contractility on intestinal permeability could not be o bserved. In conclusion, intestinal permeability and contractility are not correlated in this model of experimentally induced colitis in mice . Although simultaneous measurement in a physiological set-up is possi ble, this method has to be further validated.