Figure 5
Effect of cAMP-dependent and cholinergic stimulation on pH i recovery in untransfected and pNBC1-transfected HEK293 cells. A: Forskolin did not elicit any significant changes in pHi recovery in untransfected cells (n = 6). Again, transfected cells displayed a significantly faster pHi recovery under control conditions than their untransfected counterparts (*: p < 0.05 vs. untransfected control, Student's t-test for paired samples, n = 6). However, forskolin strongly inhibited pHi recovery in pNBC1-transfected HEK293 cells (**: p < 0.01 vs. unstimulated control, Student's t-test for unpaired samples, n = 7). B: Carbachol caused a slight acceleration of pHi recovery in untransfected cells, which might be due to effects on endogenous Na+/H+ exchange or on Na+/HCO3- exchanger isoforms other than pNBC1 or kNBC1 (*: p < 0.05 vs. unstimulated control, Student's t-test for unpaired samples, n = 6). pNBC1 transfection again led to a significantly faster pHi recovery (**: p < 0.05 vs. untransfected control, Student's t-test for paired samples, n = 8). However, carbachol did not cause any additional significant changes to pHi recovery in transfected cells (ns: not significant, n = 8).