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THE INTERACTION OF PROTEIN‐BOUND HEPARIN AND ANTITHROMBIN III
Author(s) -
Shanberge J. N.,
Sridhar C. N.
Publication year - 1981
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1981.tb29778.x
Subject(s) - hemostasis , antithrombin , associate editor , medicine , general hospital , library science , general surgery , computer science , heparin
When commercially prepared porcine mucosal heparin is added to human plasma, some of the heparin fractions form a complex with antithrombin III activating it to an immediate inhibitor of thrombin as well as of other serine proteases. Certain fractions of heparin may complex with other proteins such as alpha 2-macroglobulin, another progressive inhibitor of thrombin. Without complexing with antithrombin III, this protein-bound heparin fraction(s) still retains the capacity to activate it to an immediate inhibitor of thrombin. Protamine sulfate inactivates those heparin fractions that bind to antithrombin III but not those bound to alpha 2-macroglobulin. Activated antithrombin III may undergo a molecular change in the presence of protamine which not only changes it back to a progressive inhibitor but makes it resistant to activation by the protein-bound heparin fraction(s). However, it can still be reactivated by other heparin fractions in fresh whole heparin. The observations presented may help explain heparin "rebound" in patients believed adequately neutralized with protamine.