PAI-1 protein concentrations in bleomycin-injured WT mice. WT mice were given intratracheal bleomycin (1.15 μg/kg in 50 μL of sterile PBS) on day 0. On day 9 or day 19, animals were killed and plasma and bronchoalveolar lavage (BAL) fluid were collected. The concentrations of total and active PAI-1 were measured with a bead-based ELISA. (A) Total PAI-1 concentration in plasma. (B) Active PAI-1 concentration in plasma. (C) Total PAI-1 concentration in BAL fluid. (D) Active PAI-1 concentration in BAL fluid. Results are reported as the mean concentration in pg/mL ± SEM. N = 6-8 mice per time point.