Thromb Haemost 1982; 48(01): 054-058
DOI: 10.1055/s-0038-1657215
Original Article
Schattauer GmbH Stuttgart

The Role of Factor IX in Tissue Thromboplastin Induced Coagulation

Autoren

  • A M H P van den Besselaar

    The Haemostasis and Thrombosis Research Unit, Leiden University Hospital, Leiden, The Netherlands
  • I E Ram

    The Haemostasis and Thrombosis Research Unit, Leiden University Hospital, Leiden, The Netherlands
  • G H J Alderkamp

    The Haemostasis and Thrombosis Research Unit, Leiden University Hospital, Leiden, The Netherlands
  • R M Bertina

    The Haemostasis and Thrombosis Research Unit, Leiden University Hospital, Leiden, The Netherlands
Weitere Informationen

Publikationsverlauf

Received 18. Januar 1982

Accepted 05. Mai 1982

Publikationsdatum:
13. Juli 2018 (online)

Summary

Tissue thromboplastin apoprotein was partially purified from human brain. The apoprotein was recombined with mixed phospholipids to yield active thromboplastin. The recombined thromboplastin induced proteolytic activation of isolated human factor IX in the presence of factor VII and Ca2+. The clotting times of various deficient plasmas were determined as a function of apoprotein concentration, keeping the phospholipid concentration constant. The clotting times of a factor XII-deficient plasma were the same as those of a factor XII/factor IX-deficient plasma, except at very low apoprotein concentrations. However, under those conditions the difference in clotting times was independent of the presence of anti-factor VII serum. Similar observations were made for factor XI-deficient plasma in comparison with factor XI/factor IX-deficient plasma. These results indicate that activation of factor IX by factor VII/tissue thromboplastin does not significantly contribute to plasma coagulation.