Fig. 3. Influence of IFN on mannitol and FD10 permeability across T84 monolayers. Following incubation with IFN-(0-10 ng/ml) for 48 hours, T84 monolayers were washed with HBSS and mounted in Ussing chambers. 100 µM [¹⁴C]mannitol or 10 µM FD10 (final concentrations) were added to the apical chamber and samples removed every 30 minutes for 3 hours for analysis of probe permeation. Results are shown as fold increase in permeability of mannitol and FD10 above control. P_app values for mannitol and FD10 in control monolayers were 0.53±0.15x10^–6 and 0.015±0.005x10^–6 cm/second respectively. Data are expressed as mean±s.e.m. of four monolayers in each group. Significant differences in permeability were observed; **P<0.01; *P<0.05 compared with control levels as indicated.