Thrombolytic agent plasminogen activator

PA S1 S01.232 /-Plasminogen activator Used as therapeutic thrombolytic agent... 

Tissue paper products, 13 129-130 Tissue plasminogen activator (t-PA) bioseparation from mammalian cell culture, 3 821-826 peptide map, 3 841, 842 selling price, 3 817t Tissue reactions, to sutures, 24 218 Tissue-type plasminogen activator (t-PA) and hemostatic system, 4 89 human, use as thrombolytic agent,... 

Although most of the enzyme-based drugs are inhibitors of enzymes, a number of enzyme preparations have also been developed as drugs for the treatment of a number of diseases. The development of enzymes as therapeutics has been made easier due to the advances in biotechnology. Most successful example of enzyme therapy includes various preparations of plasminogen activators (thrombolytic or fibrinolytic agents) such as a bacterial protein streptokinase and two plasminogen activators... 

Plasminogen, an inactive precursor, is activated to plasmin which as a protease is able to break down fibrin clots. The thrombolytic agents in use promote the conversion of plasminogen to plasmin at the site of a thrombus. Indications include post-myocardial infarction treatment. The thrombolytic must be administered within 6 hours for an optimal effect. Other indications are treatment of acute pulmonary thromboembolism, deep-vein thrombosis, acute arterial thrombosis and thromboembolism, as well as in the clearance of arteriovenous catheters and can-nulae. Agents are streptokinase, anistreplase, urokinase, alteplase, reteplase and tenecteplase. 

Thrombolytic drugs are plasminogen activators. The ideal thrombolytic agent is one that can be administered... 

E Role in therapy Thrombolytic agents currently licensed for the treatment of AMI in the United States include streptokinase, tissue plasminogen activator, anistreplase, reteplase, and tenecteplase. TNKase and alteplase have similar clinical efficacy for thrombolysis after myocardial infarction (i.e., similar mortality and intracranial hemorrhage rates). However, advantages of TNKase include ease and rapidity of administration, longer half-life, greater fibrin specificity, and lower noncerebral bleeding rates. Reteplase shares some characteristics of tenecteplase (e.g., similar half-life, rapid onset, and ease of administration). 

While some parenteral injections, such as intravenous administration, provide rapid and predictable access to the circulation and tissues, therapeutic proteins are rapidly cleared from the system, and thus such administrations may result in very short durations of action. Regardless of route of administration, therapeutic proteins may exhibit limited distribution outside of endothelial cells lining blood vessels. This may be advantageous for thrombolytic agents, such as tissue plasminogen activator, which is used for rapid fibrinolytic actions at... 

Reteplase (Retavase) and tenecteplase (TNKase) are newer thrombolytics. These agents are derived of human tissue plasminogen activator, and therefore... 

Thrombolytic agents such as streptokinase, urokinase, and recombinant tissue-type plasminogen activator... 

All patients with acute myocardial infarction should be considered for intravenous thrombolytic therapy with streptokinase, tissue plasminogen activator (TPA), or anistreplase because these agents are effective in both preserving cardiac function and reducing mortality. 

Tissue plasminogen activator (tPA) is a protease with 527 amino acids and 4 glycosylation sites that acts in vivo as a thrombolytic agent. Its function is to proteolytically convert the zymogen, plasminogen, into active plasmin, which in turn degrades fibrin strands, thus dissolving the clots (Walsh, 2003). For this reason, recombinant tPA molecules... 

Urokinase is also a thrombolytic agent, used for treating pulmonary embolism. Two variants of this protease have already been isolated one of 54 kDa and another of 33 kDa, both displaying proteolytic activity over plasminogen. Until recently, the only exogenous source for this enzyme was urine. However, in 2002 the product called Abbokinase, which is produced in neonatal kidney tissue culture, was approved in the USA. 

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