Figure 6.

RMLMC produced PGE₂ in response to IL-1β stimulation, while treatment with an EP4 receptor antagonist maintained their physiological contractility. (A) PGE₂ levels in RMLMC supernatant were increased in response to IL-1β (20 ng·mL⁻¹), but not TNF-α (20 ng·mL⁻¹). (B) RMLMC contraction was significantly inhibited by PGE₂ (10⁻⁵ M) stimulation (similar to the relaxation effect to IL-1β), compared with control. (C) The EP4 receptor antagonist (GW627368X) restored RMLMC contraction that had been suppressed by IL-1β. GW627368X at 10⁻⁷ and 10⁻⁶ M reversed the relaxation effect of IL-1β on RMLMC at day 4; n = 3 for Figure 6A, n = 5 for Figure 6B and C, ***P < 0.001 versus control; one-way anova, Bonferroni's post hoc test; data are mean ± SEM.