Circulating t-PA, plasminogen, and fibrinogen levels and clot lysis in virus-injected mice. Measurements were performed 4 days after virus injection with the indicated dose of AdRR 5 or AdCMVt-PA^CB. Values are expressed as mean ± SEM of the indicated number of mice in parentheses. (Top panel) t-PA antigen and activity levels as a function of virus dose. Human t-PA antigen levels (open bars) in plasma of saline- and AdRR5-injected mice were not significantly different from background (<0.6 ng/mL). For reference purposes, t-PA antigen levels in t-PA^+/+ mice are ∼2 ng/mL. t-PA activity levels are shown by the solid bars. (Middle panel) Fibrinogen and plasminogen levels as a function of virus dose in AdRR5 and AdCMVt-PA^CB-injected t-PA^−/− mice. *, P < .005 v AdRR5-injected mice. Fibrinogen levels are shown by open bars and plasminogen levels (expressed as the fraction of plasminogen present in pooled plasma of untreated mice) are shown as solid bars. (Bottom panel) Lysis of emboli in uninfected or virus-infected t-PA^−/− mice. Three days after infection of mice with the indicated dose (pfu) of control AdRR5 or AdCMVt-PA^CB virus, a clot was injected, and the residual radioactivity measured after 16 hours. *, P = .01 v saline- and AdRR5-injected t-PA^−/− mice.