Discover

(Redirected from Activase)

'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.

Contents

Function

Gene

Clinical applications

References

See also

External links

Function

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

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

Clinical applications

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 three hours of the event to be given intravenously, or within six hours to be administered through an arterial catheter directly to the site of occlusion. 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. TPA appears to show benefit not only for large artery occlusions, but also for lacunar strokes. Since PLAT dissolves blood clots, there is risk of hemorrhage with its use.
Recently tPA has been used to dissolve a hematoma associated with hemorrhagic strokes and brain injury.
Additionally, people with frostbite who were treated with tPA had fewer amputations than those who were not^[1].

References

1. Reduction of the Incidence of Amputation in Frostbite Injury With Thrombolytic Therapy, Bruen et al., 2007;142:546-553.

See also

★ Thrombolysis

★ Ultrasound-Enhanced Systemic Thrombolysis

External links

★ http://www.americanheart.org/presenter.jhtml?identifier=4751

★ Widening the Window : Strategies to buy time in treating ischemic stroke - Scientific American Magazine (August 2005)