Fibrinólisis

Fibrinólisis is a crucial physiological process that involves the breakdown of fibrin, a protein that forms the meshwork of blood clots. This process is essential for maintaining the patency of blood vessels and preventing excessive clot formation. The primary enzyme responsible for fibrinolysis is plasmin, which is activated from its inactive precursor, plasminogen. Plasminogen is converted to plasmin by activators, most notably tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA). These activators can be released from endothelial cells lining blood vessels or from other tissues. Once plasmin is formed, it circulates in the bloodstream and binds to fibrin clots, cleaving the fibrin strands and thereby dissolving the clot. The breakdown products of fibrinolysis are known as fibrin degradation products (FDPs) or D-dimers, which can be measured in blood tests to assess the activity of the fibrinolytic system. In addition to its physiological role, fibrinolysis can be therapeutically induced. Fibrinolytic agents, such as recombinant tPA, are used in medicine to dissolve blood clots that cause conditions like myocardial infarction (heart attack) and ischemic stroke. Conversely, a deficiency in fibrinolytic activity can lead to thrombotic disorders, where clots form inappropriately.