Day 21 mutant PAI-1 protein concentrations in bleomycin-injured transgenic mice. PAI-1^−/− mice that transgenically express PAI-1(V+P+), PAI-1(V+P-) or PAI-1(V-P+) off of the preproendothelin promoter were treated with intratracheal bleomycin (1.15μg/kg in 50 μL of sterile PBS) on day 0. Groups of WT and PAI-1^−/− mice were also treated with bleomycin. A control group of WT mice was left uninjured. On day 21, bronchoalveolar lavage fluid (BAL) was collected from each animal and the concentrations of total (A) and active (B) PAI-1 were measured with a bead-based ELISA. Results are reported as the mean concentration in pg/mL ± SEM. N = 6-8 mice per time point. Groups are compared with a 1-way ANOVA with Newman-Kuels posthoc multiple comparison test.