Fig. 4. Changes in [Ca²⁺]_i (A), pHi (B) and proton secretion rate (C) of trout hepatocytes upon exposure of cells to Ca²⁺-free medium containing 0.5 mmol l^–1 EGTA followed by addition of 25 µmol l^–1 of the intracellular Ca²⁺ chelating agent BAPTA-AM. The effect of exposure to 25 µmol l^–1 BAPTA-AM in the presence of Ca²⁺_e is depicted as BAPTA control in the three experiments. Data are means ± s.e.m. of 27–38 cells from 3–4 independent preparations in A and B and from three independent preparations in C.