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Updated: Aug 15, 2026

A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
Effects of unfractionated and fractionated heparin on platelet function
1Department of Internal Medicine, University Hospital, Justus Liebig University, Giessen, FRG.
Abstract:
Heparin-induced alterations of platelet function have repeatedly been reported over the last 30 years. The development of low-molecular-weight (LMW) heparin fractions prompted us to compare the effect of unfractionated (UF) heparin and LMW heparin on platelet function. Heparin was applied intravenously to healthy volunteers in a dose of 100 U (antifactor Xa)/kg body weight. Sequential evaluation of platelet function ex vivo confirmed that UF heparin may activate platelets in vivo. Studying the ADP-induced fibrinogen binding to platelets in vivo, we were able to show that the effect of heparin on platelets is antibody- and antithrombin-III-independent. LMW heparin fractions in general exhibit a reduced platelet activating activity although there are differences between the LMW heparin fractions available. The stimulating effect of LMW heparin on platelets disappears below a mean molecular weight of 3,000 daltons.
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