Figure 5. Effects of luminal inhibitors on forskolin-stimulated Cl⁻ flux across the luminal membrane.

Initially the bath and lumen of the duct segments were perfused with the standard HCO₃⁻-buffered solution and forskolin (1 μm) was applied to the bath. The luminal perfusate was switched to the low Cl⁻-high HCO₃⁻ solution in the absence and presence of 100 μm glibenclamide (A), 500 μm H₂DIDS (B), or 10 μm NPPB (C). Each trace is a representative of four experiments.