Fig. 2. Changes in pHi of trout hepatocytes following addition of 0.5 µmol l^–1 ionomycin (A) or 0.1 µmol l^–1 thapsigargin (B) (at the time indicated by the arrows) using Ca²⁺-containing medium, Ca²⁺-free medium and Ca²⁺-free medium following incubation of cells with the intracellular Ca²⁺ chelating agent BAPTA-AM (25 µmol l^–1). Data are means ± s.e.m. of 19–128 cells from 3–16 independent preparations in A and of 28–39 cells from 3–4 independent preparations in B.