Time course and onset of clot lysis. Lysis of ¹²⁵I-fibrin–labeled pulmonary clots in t-PA^−/− mice over the course of 4 or 16 hours. Clot injection was performed at the indicated time or day after injection with either 2 × 10⁹ pfu AdRR5 (open bars) or AdCMVt-PA^CB virus (solid bars). Clot lysis after 4 hours was measured after coinjection of the plasma clot and virus; clot lysis 4 and 7 days after virus delivery was determined by measuring the extent of lysis 16 hours after injection of the clot. Values are expressed as percent of total radioactivity injected and represent mean ± SEM of the indicated number of mice in parentheses. *P < .05 v lysis in AdRR5 infected mice.