Fig. 4. Secreted fluid pH and concentrations of K⁺, Na⁺ and Cl^– before (open bars) and after (solid bars) the addition of 10 µmol l^–1 Tenmo-ADFb (ADFb), 1 nmol l^–1 Achdo-KII (AKII) and 1 mmol l^–1 8-bromo cyclic GMP (cGMP). Bars represent the means + 1 s.e.m. for the number of replicates shown in parentheses. Asterisks indicate where the change in composition following addition of the secretagogue is significant in a paired t-test; ^*P<0.05; ^**P<0.01; ^***P<0.001.