Fig. 4.

A6KD reduces the rate of Cl⁻-dependent acidification (a measure of Cl⁻-HCO₃⁻ exchange) in Caco-2 monolayers compared with Con and Scram monolayers. Intracellular pH was measured in cells superfused with standard HCO₃⁻/CO₂ buffer with and without Cl⁻. As shown in A, removal of Cl⁻ resulted in an increase in intracellular pH (pH_i) for all monolayers whereas readmission of Cl⁻ prompted a return of pH_i to initial values. The average initial rates (δpHi/min) of alkalinization on Cl⁻ removal and acidification on Cl⁻ readmission are presented in B and C, respectively. In A6KD monolayers, Cl⁻-HCO₃⁻ exchange is significantly reduced to about half that of Con or Scram monolayers as judged by a 1-way ANOVA. Typical recordings of at least 7 experiments.