Concentrations of plasma antiplasmin, factor VIII, and fibrinogen.

Plasma antiplasmin (top), factor VIII (middle), and fibrinogen concentrations (bottom) in animals exposed to TPA (open symbols) or plasmin (solid symbols) over the course of the 180-minute observation. Mean results for each cohort of 5 animals expressed as percent of pretreatment value at −30 minutes, normalized to 100%. Data are corrected for results obtained with saline alone, which was associated with a 5% decrease in all results during the 60-minute infusion and with a 10% decrease in values of samples obtained from 60 to 180 minutes. Results for TPA were not different at dosages of 0.25 mg/kg (○), 0.5 mg/kg (■), or 1.0 mg/kg (⋄). Plasmin showed a dose-dependent decrease in all 3 assays on exposure to increasing dosages of 4 mg/kg (♦), 6 mg/kg (▪), and 8 mg/kg (●). Antiplasmin activity was fully depleted with plasmin at 6 mg/kg, a dose that decreased fibrinogen and factor VIII to 20% to 30% of initial activity. Only at a dose of 8 mg/kg did plasmin cause depletion of fibrinogen and factor VIII to levels at or below the lower limit of quantification.