Figure 3.

EP₁, EP₂, and EP₃ receptors are not involved in mediating the stimulatory effect of PGE₂ on ENaC. In the left and middle panels, representative I_SC recordings are shown. At the time point indicated by an arrow, cells were exposed to 10 µM AH6809 (EP₂ receptor antagonist; left panel, solid line), 100 nM sulprostone (EP₁/EP₃ receptor agonist; middle panel, solid line), or vehicle in matched control recordings (control, dashed line). Approximately 30 min later, all cells were exposed to 100 nM basolateral PGE₂ and subsequently to apical amiloride (Ami; 10 µM) as indicated. Summary data (right panel) are presented as ΔI_SC values, which were determined by subtracting the corresponding baseline I_SC from the I_SC reached in the presence (+) or absence (−) of PGE₂, AH6809, and sulprostone as indicated. Data are presented as individual values and their mean ± SEM; paired data are connected by dashed lines. Numbers of experiments are given in parenthesis. ns, P > 0.05, one-way ANOVA with Tukey's multiple comparison test.