Skip to main content

Thrombin activates factor XI on activated platelets in the absence of factor XII.

Publication ,  Journal Article
Oliver, JA; Monroe, DM; Roberts, HR; Hoffman, M
Published in: Arterioscler Thromb Vasc Biol
January 1999

Thrombin can activate factor XI in the presence of dextran sulfate or sulfatides. However, a physiological cofactor for thrombin activation of factor XI has not been identified. We examined this question in a cell-based, tissue factor-initiated model system. In the absence of factor XII, factor XI enhanced thrombin generation in this model. The effect on thrombin generation was reproduced by 2 to 5 pmol/L factor XIa. A specific inhibitor of factor XIIa did not diminish the effect of factor XI. Thus, factor XI can be activated in a model system that does not contain factor XIIa or nonphysiological cofactors. Preincubation of factor XI with activated platelets and thrombin or factor Xa enhanced subsequent thrombin generation in the model system. Preincubation of factor XI with thrombin or factor Xa, but without platelets, did not enhance thrombin generation, suggesting that these proteases might activate factor XI on platelet surfaces. Thrombin and factor Xa were then directly tested for their ability to activate factor XI. In the presence of dextran sulfate, thrombin or factor Xa activated factor XI. Thrombin, but not factor Xa, also cleaved detectable amounts of factor XI in the presence of activated platelets. Thus, thrombin activates enough factor XI to enhance subsequent thrombin generation in a model system. Platelet surfaces might provide the site for thrombin activation of functionally significant amounts of factor XI in vivo.

Duke Scholars

Altmetric Attention Stats
Dimensions Citation Stats

Published In

Arterioscler Thromb Vasc Biol

DOI

ISSN

1079-5642

Publication Date

January 1999

Volume

19

Issue

1

Start / End Page

170 / 177

Location

United States

Related Subject Headings

  • Thrombin
  • Prothrombin
  • Platelet Activation
  • Lipoproteins
  • Kininogens
  • Humans
  • Factor XII
  • Factor XI
  • Factor X
  • Factor VIII
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Oliver, J. A., Monroe, D. M., Roberts, H. R., & Hoffman, M. (1999). Thrombin activates factor XI on activated platelets in the absence of factor XII. Arterioscler Thromb Vasc Biol, 19(1), 170–177. https://doi.org/10.1161/01.atv.19.1.170
Oliver, J. A., D. M. Monroe, H. R. Roberts, and M. Hoffman. “Thrombin activates factor XI on activated platelets in the absence of factor XII.Arterioscler Thromb Vasc Biol 19, no. 1 (January 1999): 170–77. https://doi.org/10.1161/01.atv.19.1.170.
Oliver JA, Monroe DM, Roberts HR, Hoffman M. Thrombin activates factor XI on activated platelets in the absence of factor XII. Arterioscler Thromb Vasc Biol. 1999 Jan;19(1):170–7.
Oliver, J. A., et al. “Thrombin activates factor XI on activated platelets in the absence of factor XII.Arterioscler Thromb Vasc Biol, vol. 19, no. 1, Jan. 1999, pp. 170–77. Pubmed, doi:10.1161/01.atv.19.1.170.
Oliver JA, Monroe DM, Roberts HR, Hoffman M. Thrombin activates factor XI on activated platelets in the absence of factor XII. Arterioscler Thromb Vasc Biol. 1999 Jan;19(1):170–177.

Published In

Arterioscler Thromb Vasc Biol

DOI

ISSN

1079-5642

Publication Date

January 1999

Volume

19

Issue

1

Start / End Page

170 / 177

Location

United States

Related Subject Headings

  • Thrombin
  • Prothrombin
  • Platelet Activation
  • Lipoproteins
  • Kininogens
  • Humans
  • Factor XII
  • Factor XI
  • Factor X
  • Factor VIII