Premium
Platelets and Initiation of Intrinsic Clotting
Author(s) -
Schiffman Sandra,
Rapaport Samuel I.,
Chong May M. Y.
Publication year - 1973
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1973.tb01689.x
Subject(s) - platelet , chemistry , clotting factor , partial thromboplastin time , thromboplastin , medicine , endocrinology , coagulation , biochemistry
S ummary . Comparison of activities in platelet rich and platelet poor plasmas from normal donors and patients deficient in either factor VIII, IX, XI or XII indicates that platelets contain activities which can partially substitute for plasma factors XI and XII. The factor‐XI‐like activity is expressed in a one‐stage activated partial thromboplastin assay and in an intact prothrombin consumption system. The factor‐XII‐like activity is scarcely detectable in a one‐stage assay but markedly enhances the defective prothrombin consumption of factor XII deficient plasma. Intact prothrombin consumption tests with platelet poor plasmas fortified with cephalin show that in the presence of high concentrations of platelet factor 3 activity only trace contact activation is required to promote good prothrombin consumption. The platelet, by supplying both platelet factor 3 and activities bypassing plasma contact activation factors XI and XII, may provide an important route for activating intrinsic clotting.