FIG 8.

The permeability of the epithelium mediated by fecal supernatants from UC patients is lost in PAR2^−/− mice. The colonic epithelia of mice were exposed to fecal supernatants generated from UC patients, and permeability was measured using Ussing chambers. (A) Exposure of the colonic epithelia of WT mice to supernatants from UC patients (n = 7) for 2 h induced a significant 2-fold increase in paracellular permeability over that of controls (P < 0.05). (B) Exposure of the colonic epithelia of PAR2^−/− mice to supernatants from UC patients (n = 7) for 2 h did not exhibit a significant difference in paracellular permeability from controls. (C) Exposure of the colonic epithelia of WT mice to a subset of supernatants from UC patients (n = 4) for 2 h induced a reduced level of paracellular permeability when these supernatants were incubated with protease inhibitors. Comparisons were made using the nonparametric Mann-Whitney test.