Fig. 4. Effects of various factors on intracellular acidification induced by 1 µmol l^–1 DA in duct cells of lobe preparations in CO₂/HCO₃^–-buffered saline. (A) The acidification is still present in CO₂/HCO₃^–-buffered saline (N=5). (B) Bath application of 10 µmol l^–1 bumetanide does not influence the acidification (N=5). (C) The combined bath application of 10 µmol l^–1 bumetanide and 500 µmol l^–1 DIDS strongly reduces the acidification (N=5). (D) The combined bath application of 10 µmol l^–1 bumetanide and 50 µmol l^–1 EIPA also reduces the acidification dramatically (N=5). (E) In addition, the combined bath application of 10 µmol l^–1 bumetanide and 500 µmol l^–1 acetozolamide decreases the acidification (N=5).