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Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
13:08

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay

Published on: September 9, 2012

Biosynthetic origin and functional significance of murine platelet factor V

Tony L Yang1, Steven W Pipe, Angela Yang

  • 1Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA.

Blood
|June 21, 2003
PubMed

Insights

Platelet Factor V (FV) is synthesized by bone marrow cells, not absorbed from plasma. This finding reveals the primary source of platelet FV, crucial for hemostasis.

Area of Science:

  • Hematology
  • Molecular Biology
  • Hemostasis Research

Background:

  • Factor V (FV) is essential for hemostasis, existing in both plasma and platelet compartments.
  • Previous studies suggested platelet FV originates from plasma uptake, particularly in transplant recipients.
  • The precise biosynthetic origin of platelet-associated FV remained unclear.

Purpose of the Study:

  • To investigate the primary biosynthetic origin of platelet and plasma Factor V (FV) pools.
  • To determine if platelet FV is synthesized intrinsically or acquired from plasma.
  • To assess the necessity of platelet FV for hemostasis.

Main Methods:

  • Bone marrow transplantation of Factor V-null (Fv-/-) fetal liver cells into wild-type mice.
  • Fractionation of whole blood to quantify platelet-associated FV activity.
  • Assessment of FV levels and bleeding phenotypes in recipient mice.

Main Results:

  • Mice receiving Fv-null cells showed significantly reduced platelet FV activity (<1% of normal).
  • Total FV levels were only mildly decreased, indicating minimal plasma uptake compensation.
  • No spontaneous hemorrhage or excessive bleeding after minor trauma was observed in these mice.

Conclusions:

  • Murine platelet FV is exclusively derived from primary biosynthesis within marrow-derived cells, likely megakaryocytes.
  • An intact platelet FV pool is not essential for preventing spontaneous hemorrhage or bleeding after minor injury.
  • This study clarifies the intrinsic origin of platelet FV, distinct from plasma sources.

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