Figure 4.

TNF-α (A–C) and IL-6 (D) concentrations in the supernatants of isolated murine alveolar macrophages. Cells were treated with LPS (10 ng·mL⁻¹) for 4 h in the presence of (A) vehicle (veh) or PGE₂ (concentrations as indicated), n = 5, (B) vehicle (veh) or PGE₂ (30 nmol·L⁻¹) in the absence or presence of the EP₄ receptor antagonists ONO AE3-208 (300 nmol·L⁻¹) or GW627368X (GW, 1 μmol·L⁻¹) for 30 min, n = 6, (C) vehicle (veh) or the EP₄ receptor agonist ONO AE1-329 (concentrations as indicated), n = 8, (D) vehicle (veh) or PGE₂ (30 nmol·L⁻¹) or ONO AE1-329 (100 nmol·L⁻¹) in the absence or presence of the EP₄ receptor antagonist ONO AE3-208 (300 nmol·L⁻¹), n = 7. Data are shown as mean + SEM of n independent experiments performed in triplicate. Data were analysed using one-way anova for repeated measurements and multiple comparisons were calculated with Tukey’s post test. *P < 0.05, **P < 0.01, ***P < 0.001 as compared with LPS treatment, #P < 0.05 as compared with PGE₂ or EP₄ agonist treatment.