Tissue plasminogen activator (abbreviated PLAT or tPA) is a secreted serine protease which converts the proenzyme plasminogen to plasmin, a fibrinolytic enzyme. Plasminogen is synthesized as a single chain which is cleaved by PLAT into the two chain disulfide linked plasmin. This enzyme plays a role in cell migration and tissue remodeling. Increased enzymatic activity causes hyperfibrinolysis, which manifests as excessive bleeding; decreased activity leads to hypofibrinolysis which can result in thrombosis or embolism.

Gene

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Alternative splicing of the PLAT gene, PLAT, produces three transcripts.

Applications

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Recombinant PLAT is used in diseases which feature blood clots, such as myocardial infarction and stroke. To be effective, PLAT must be administered within the first six or so hours of the attack. The guideline in Ontario, Canada hospitals for ischemic strokes is that tPA must be given within 3 hours of the onset of symptoms. Because of this, only about 3% of patients qualify for this treatment. Since PLAT dissolves blood clots, there is risk of hemorrhage with its use.

See also

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• Thrombolysis
• Ultrasound-Enhanced Systemic Thrombolysis

External links

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• http://www.americanheart.org/presenter.jhtml?identifier=4751
• http://www.guideline.gov/summary/summary.aspx?doc_id=3422
• Widening the Window : Strategies to buy time in treating ischemic stroke - Scientific American Magazine (August 2005)

Hematology | Fibrinolytic system | EC 3.4.21

Tissue plasminogen activator | Тканевной активатор плазминогена