Related Experiment Videos
Enhanced prothrombin-converting activity and factor Xa binding of platelets activated by the alternative complement
British Journal of Haematology
|June 1, 1984
Summary
Platelet activation enhances prothrombin conversion and factor Xa binding, primarily mediated by factor V. Different activation pathways, like zymosan versus collagen, reveal distinct mechanisms in platelet-rich plasma (PRP).
Area of Science:
- Hematology
- Biochemistry
- Immunology
Background:
- Platelet activation is crucial for hemostasis and thrombosis.
- Understanding the molecular mechanisms of platelet activation is essential for developing targeted therapies.
Purpose of the Study:
- To investigate platelet prothrombin-converting activity and factor Xa binding following activation.
- To elucidate the role of factor V in platelet-mediated prothrombin conversion.
- To compare different platelet activation pathways and their effects.
Main Methods:
- Human platelet-rich plasma (PRP) was exposed to various activation conditions (zymosan, thrombin, collagen).
- Platelet-bound C3, prothrombin-converting activity, and factor Xa binding were measured.
- Factor XII-deficient plasma was used to assess factor XII's role.
- Inhibition studies using heterologous antibody to factor V were performed.
Main Results:
- Zymosan activation increased platelet-bound C3, prothrombin-converting activity, and factor Xa binding.
- Synergistic effects on prothrombin conversion and factor Xa binding were observed with zymosan and thrombin.
- Zymosan and collagen activation did not show synergism, indicating shared pathways.
- Factor V antibody completely inhibited platelet prothrombin-converting activity.
Conclusions:
- Platelet activation significantly enhances prothrombin conversion and factor Xa binding.
- Factor V is the primary mediator of platelet prothrombin-converting activity.
- Distinct pathways exist for platelet activation by different agonists like zymosan and collagen.