Figure 7. Effects of 7,8-benzoquinoline on apical and basolateral membranes of Calu-3 cells.

A, the effect of 7,8-benzoquinoline (250 μM, bs) on a Calu-3 monolayer previously exposed to nystatin on the apical side (360 μg ml⁻¹ for 30 min) in the presence of an apical-to-basolateral K⁺ gradient. Afterwards acetazolamide (100 μM, bs) and ChTx (50 nM, bl) were added as indicated. The inset illustrates a complete experiment that is typical of 3 others. B, the response to 7,8-benzoquinoline (1 mM, bs) on a Calu-3 monolayer depolarised by high K⁺ on the basolateral side and in the presence of an apical-to-basolateral Cl⁻ gradient. Acetazolamide (100 μM, bs) was added as indicated and the result is typical of 3 other experiments.