Tissue-type plasminogen activator

Tissue-type plasminogen activator (tPA) is a serine protease found in endothelial cells that plays a crucial role in the breakdown of blood clots. It is a enzyme that catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown.

Function

tPA is produced by the endothelium of blood vessels and is released into the blood after an injury. It binds to a substrate called plasminogen, which is found in the blood. This binding triggers a conformational change in plasminogen, converting it into its active form, plasmin. Plasmin then degrades fibrin, the main component of blood clots.

Clinical significance

tPA is used in medicine to break down clots in patients with ischemic stroke, myocardial infarction, and pulmonary embolism. It is administered intravenously in a hospital setting. The use of tPA is not without risks, as it can cause bleeding and hemorrhagic stroke.

Pharmacology

In pharmacology, tPA is used as a thrombolytic agent to treat acute ischemic stroke. It is the only approved treatment for dissolving blood clots that cause most types of stroke. The drug is administered intravenously and can be given within 4.5 hours of the onset of stroke symptoms.

See also

• Plasmin
• Fibrin
• Ischemic stroke
• Myocardial infarction
• Pulmonary embolism