Fig. 8. Acid-activated basolateral Na⁺/H⁺ exchange rates in differentiated C2NHE2KD cells. The experimental design and solutions were identical to those in Fig. 5. (A) pH_i-curve of C2NHE2KD without inhibitors, (B) in the presence of 3 μM HOE642, (C) in the presence of 60 μM HOE642. (D) Comparisons of acid-induced pH_i recovery rates under control, 3 μM HOE642 and 60 μM HOE642 treatments in C2NHE2KD cells. The acid-activated total basal Na⁺/H⁺ exchange rates in C2NHE2KD cells was 0.34 ± 0.036 (△pH/min). 3 μM HOE642 reduced this rate to 0.083 ± 0.011 (△pH/min). 60 μM HOE642 reduced this rate to 0.057 ± 0.007 (△pH/min). (E) Comparisons of initial pH_i at the beginning of pH_i recovery under control, 3 μM HOE642 and 60 μM HOE642 treatments in C2NHE2KD cells. (n=5, mean ± SEM, one-way ANOVA with Tukey's multiple comparison tests, ***p<0.0001).