Figure 4.

(A) Concentration–response curves to the selective EP₁/EP₃ receptor agonist sulprostone in endothelium-intact guinea pig aorta after treatment with the selective EP₃ receptor antagonist ONO-AE5-599 (O599). (B) Concentration–response curves to PGE₂ in rat tracheal segments pre-contracted with 0.3 μM CCh and treated with the EP₄ receptor antagonist ONO-AE3-208 (O208). All experiments were performed in the presence of 3 μM indomethacin and in panel A; 10 nM of the EP₁ receptor antagonist ONO-8130 was also added. Data represent mean ± SEM (n = 4–8).