Fig. 3. Recordings of the effects of (A) 1 µmol l^–1 concanamycin A (ConA), (B) Na⁺-free physiological saline (PS), (C) 1 µmol l^–1 ConA in Na⁺-free PS (D) and 50 µmol l^–1 EIPA together with 1 µmol l^–1 ConA, on pH changes induced by a brief application of 20 mmol l^–1 NH₄Cl to isolated salivary ducts. (E) Quantitative analysis of the rates of pH_i recovery in the above experiments. Values are means ± s.e.m.; the number of experiments is given under each bar; one-way ANOVA, *P<0.05, **P<0.01.