Focussing of the clot: normal and pathologic mechanisms.

Overview

Several physiologic antithrombotic mechanisms operate to prevent clot formation under normal circumstances and to focus the clot on the site of damage upon vascular injury. These mechanisms, which involve prostacyclin (PGI2), antithrombin III, protein C, and the fibrinolytic system, are interrelated, are activated by thrombin generation, and are dependent upon the integrity of normal endothelium surrounding the focus of injury. Acquired or inherited abnormalities in each of these physiologic antithrombotic systems have been linked to clinical bleeding and thrombotic disorders.