Anti-ICAM/tPA accumulated in pulmonary vasculature facilitates fibrinolysis.

Isolated rat lungs were perfused with anti-ICAM/tPA (▨) or IgG/tPA (▪) for 30 minutes at 37°C and washed free of unbound conjugates (5 minutes of noncirculating perfusion with a buffer). (A) Pulmonary uptake of ¹²⁵I-tPA conjugated to either anti-ICAM or control IgG. (B) Fibrinolysis of fibrin clots by aliquots of lung homogenates obtained after perfusion. (C) Conversion of chromogenic tPA substrate perfused after the conjugates. (D) Dissolution of radiolabeled fibrin emboli lodged in the pulmonary vasculature after perfusion of the conjugates. The data are shown as means ± SEM, n = 4.