Figure 9. Effect of extracellular Cl⁻ removal on recovery from NH₄Cl-induced intracellular acidification in HCO₃⁻-CO₂-buffered solution containing valinomycin and amiloride.

A and B, representative experiments showing the effect of Cl⁻ -free solution on recovery. After NH₄Cl treatment, cells were exposed to Na⁺-free solution containing 5 μm valinomycin (3 min) before either control buffer containing amiloride (1 mm) and valinomycin (5 μm; A) or Cl⁻-free buffer with valinomycin and amiloride (B). C, effect of Cl⁻-free solution containing valinomycin and amiloride on mean initial rates of pH_i recovery. Error bars depict s.e.m. * Significant difference from recovery in control buffer (Student's unpaired t test, P < 0.05).