Figure 9. Effect of acetazolamide on anion and fluid secretion by Calu-3 cells.

A, the carbonic anhydrase inhibitor acetazolamide (100 μmol l⁻¹) abolished forskolin-stimulated secretion (n= 6). B, sequential addition of the NHE inhibitors HOE694 (10 μmol l⁻¹) and amiloride (1 mmol l⁻¹) to the basolateral side had no effect on I_eq or HCO₃⁻ secretion (n= 3). C, acetazolamide caused a small reduction in forskolin-stimulated fluid secretion by Calu-3 cells. •, I_eq; º, HCO₃⁻ secretion. ▪, without acetazolamide; ▴, with acetazolamide (n= 6). Means ± SEM.