fibrinolýzou

Fibrinolýza is a vital physiological process that breaks down blood clots. It is the body's natural mechanism for dissolving fibrin, the protein that forms the meshwork of a clot, thereby restoring blood flow. This process is crucial for preventing excessive clot formation and maintaining the patency of blood vessels.

The primary enzyme responsible for fibrinolysis is plasmin. Plasminogen, an inactive precursor, circulates in the blood and is converted to active plasmin by activators. The most important of these activators is tissue plasminogen activator (tPA), which is released from the walls of blood vessels. Other activators include urokinase plasminogen activator (uPA).

Once formed, plasmin acts by cleaving fibrin strands, breaking down the clot into smaller fragments. These fragments are then cleared from the circulation by other cellular mechanisms. The activity of plasmin is tightly regulated by inhibitors, such as alpha-2-antiplasmin and plasminogen activator inhibitor-1 (PAI-1), to prevent excessive or premature clot dissolution.

Dysregulation of fibrinolysis can lead to significant health problems. Insufficient fibrinolytic activity can contribute to thrombotic disorders, where clots form inappropriately and obstruct blood flow, leading to conditions like deep vein thrombosis or pulmonary embolism. Conversely, excessive fibrinolytic activity can result in bleeding disorders, as the body is unable to form stable clots when needed, such as during injury. Medical interventions often involve manipulating fibrinolytic pathways, for instance, using tPA to dissolve blood clots in acute myocardial infarction or ischemic stroke.