Related Experiment Video
Updated: Jul 4, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Further understanding of recombinant activated factor VII mode of action
1Division of Hematology/Oncology, Department of Medicine, Center for Thrombosis and Hemostasis, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7035, USA. dmonroe@med.unc.edu
Abstract:
Recombinant activated factor VII (rFVIIa) is being increasingly used to treat bleeding associated with a variety of non-hemophilic coagulopathic indications, and its mechanism of action in these areas is under active investigation. Numerous studies have shown that FVIIa binds with low affinity to activated platelets; rFVIIa can subsequently enhance platelet-surface thrombin generation by activating factor (F) X and by contributing additional FIXa to the hemostatic process. This FIXa can rapidly activate additional FX, which may explain why non-hemophilic coagulopathic bleeds respond to lower doses of rFVIIa than do hemophilic bleeds. However, the platelet surface may be able to process only a limited amount of FXa, accounting for the observation that some models of non-hemophilic coagulopathy show a plateau in the effect of rFVIIa.
Related Concept Videos
Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
Venous Thrombosis III: Interprofessional Care
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Clot Retraction and Fibrinolysis
Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...

