Figure 4. Rapid recovery is slowed by acetazolamide.

A, pH_i recording showing experimental protocol. Cl⁻_o was removed (replaced by gluconate) at the beginning of the recording (indicated by bar above trace) in order to inhibit Cl⁻_o-dependent acid loading transporters. Note that pH_i slowly rises as Cl⁻ leaves the cell in exchange for HCO₃⁻ and OH⁻. B, histogram showing peak pH_i following 80 mM acetate removal in Cl⁻-free solution in absence (control) and presence of 10 μM acetazolamide (ATZ) C, histogram showing time for 50 % recovery from peak pH_i in absence (control) and presence of ATZ. * Significant difference, P < 0.05; ** significant difference, P < 0.001.