Figure 4.

Evaluation of NBCe1 transport activity. (a) Original recordings of intracellular [H⁺] ([H⁺]_i) in cultured mouse cortical astrocytes during reduction of external pH and [ ${\text{HCO}}_3^{-}$] from 7.4 and 26 mM to 7.1 and 13 mM, respectively, to challenge outwardly directed NBCe1 activity, before and after application of TGF‐β (2 ng/mL, 60 min), in control, and in the presence of the Smad3 inhibitor SIS3 (3 µM) or the JNK inhibitor SP600125 (10 µM). Bar plots of the rate of acidification (b), the rate of alkalinisation (c), and the amplitude (d) as measured by changing external pH and [ ${\text{HCO}}_3^{-}$] to 7.1 and 13 mM, respectively, and back to pH 7.4 and 26 mM [ ${\text{HCO}}_3^{-}$], before and after incubation with TGF‐β in controls, and in the presence of SIS3 or SP600125. **p < .01 and ***p < .001, for the significant increase, compared to the untreated controls, using the Student's t‐test and ^{# #} p < .05, and ^### p < .001 for the significant decrease, compared to TGF‐β, using one way ANOVA and Bonferroni post hoc test. The number of cells/cultures/animals used in the experiments is indicated