Day 9 mutant PAI-1 protein concentrations in bleomycin-injured PAI-1^−/− mice. PAI-1^−/− mice were given intratracheal bleomycin (1.15 μg/kg in 50 μL of sterile PBS) on day 0. On day 8, subgroups of mice were treated with either intraperitoneal injections of PBS or 100 μg/injection every 12 hours of PAI-1(V+P+), PAI-1(V+P-) or PAI-1(V-P+). On day 9, 1 hour after the last injection, plasma and BAL fluid were collected from each animal and 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 ng/mL ± SEM. N = 5 mice per group. Groups are compared with a 1-way ANOVA with Newman-Kuels posthoc multiple comparison test.