Two forms of alpha 2-antiplasmin: post-traumatic changes in the rat.

The plasminogen-binding (PB-AP) and non-plasminogen-binding (NPB-AP) forms of alpha 2-antiplasmin (AP), were assayed in rat plasma by a modified rocket immunoelectrophoretic technique before and up to 48 h after turpentine-induced trauma, using an intermediary gel containing kringles 1-3 from plasminogen. The concentration of PB-AP was significantly elevated by 22% 24 h post-traumatically, while NPB-AP was decreased at that point in time, leaving the total AP level unchanged. Total AP increased by 57% during the period 24-48 h after trauma, mainly on account of increases in the NPB-AP form. It is concluded that the plasma level of AP can remain unchanged in spite of increased fibrinolysis inhibition, owing to a relative increase in the functionally more active PB-AP.