FIGURE 2.

Time dependence of pulmonary COX-2 activation in a rat model of LPS-induced ARDS. LPS (3 mg/kg) or an equivalent volume of sterile 0.9% saline was i.v. administered to SD rats, which were stimulated for the indicated durations. Lung tissue samples were collected after LPS administration for Western blot and ELISA analysis. (A) COX-2 protein expression was assessed via Western blot and analyzed via densitometry. Values were compared with β-actin expression. (B and C) PGE₂ and PGD₂ concentrations in homogenized lung tissue were measured via ELISA. Data are shown as mean ± SEM, n = 6–8 rats per time point per group, and are representative of four independent experiments. *p < 0.05, ***p < 0.001, ****p < 0.0001.