Inhibition of in vitro platelet aggregation and release and fibrinolysis.
Inhibition of in vitro platelet aggregation and release of contents of platelet granules is necessary in order to assess accurately platelet activation in vivo. This can be accomplished by using a variety of inhibitors added to blood collection containers. An additive mixture of citrate, theophylline, adenosine, and dipyridamole (CTAD) provides a practical alternative to a mixture of acid citrate dextrose (ACD), acetylsalicylic acid (aspirin), and prostaglandin E1 (PGE1) because of the stability problems associated with PGE1. Inhibition of in vitro fibrinolysis is essential for the accurate measurement of fibrin degradation products (FDP). This can be accomplished by using a mixture of thrombin, soybean trypsin, or aprotinin into which blood is collected. However, in patients receiving heparin, the fibrinolysis inhibitor mixture is ineffective unless it is supplemented with reptilase. With increasing use of recombinant tissue-type plasminogen activator therapy (rt-PA), an inhibitor such as D-phenylalanine-proline-arginine-chloromethylketone (PPACK) used as a blood collection additive is superior to a conventional protease inhibitor, such as aprotinin.
Narayanan
S
S
Department of Pathology, New York Medical College-Metropolitan Hospital Center, NY 10029.
D001792:Blood Platelets / Q000378:metabolism; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005342:Fibrinolysis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D013048:Specimen Handling; D010959:Tissue Plasminogen Activator / Q000037:antagonists & inhibitors
D005338:Fibrin Fibrinogen Degradation Products; D010975:Platelet Aggregation Inhibitors; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator