Representative traces (a) and summarized data (b) of the effect of amphotericin B upon short-circuit current (ΔIsc, μA cm−2 or ΔIsc, % control) in Caco-2 cells treated for 24 h in the absence (vehicle) and in the presence of plus interferon-γ (IFN-γ, 1000 U ml−1). (c) Effect of PDBu (1 μM) upon changes in short-circuit current (ΔIsc, % control) induced by amphotericin B (1.0 μg ml−1) applied from the apical cell side in Caco-2 cells treated for 24 h in the absence (vehicle) and in the presence of plus interferon-γ (IFN-γ, 1000 U ml−1). Columns represent means of four experiments per group and vertical lines show s.e.m. Significantly different from control values (*P<0.05) using the Student's ‘t'-test.