Figure 3.

Inhibition of pendrin-mediated Cl⁻/HCO₃⁻ exchange. A) Schematic of assay showing replacement of extracellular Cl⁻ for gluconate in BCECF-loaded FRT cells expressing human pendrin causes Cl⁻ efflux and HCO₃⁻ influx, resulting in cytoplasmic alkalinization. B) Representative BCECF fluorescence data showing inhibition of Cl⁻/HCO₃⁻ exchange by PDS_inh-A01 and PDS_inh-C01. C) Concentration-dependent inhibition of pendrin-mediated Cl⁻/HCO₃⁻ exchange by PDS_inh-A01 and PDS_inh-C01. Data shown as means ± sem (n = 3–9 cultures). D) Control study done in nontransfected and pendrin expressing cells in absence of HCO₃⁻. BCECF ratio imaging indicated initial cytoplasmic pH of ∼7.3 in all cultures studied.