Increased adsorption of high molecular weight kininogen to heparin-coated artificial surfaces and correlation to hemocompatibility.
During the past 10 years investigations have demonstrated that heparin-coated devices used for extracorporeal circuits show an improved hemocompatibility. We investigated the pathway of adsorption of plasma proteins at heparin-coated artificial surfaces and the further activation of the humoral and cellular defense mechanisms of the blood. Twenty milliliters of fresh human blood (1 IU heparin/ml) filled a 50 cm long tubes (with and without covalent heparin-coating), prepared as an in vitro "Closed-Loop" model and recirculated at a temperature of 37 degrees C. After 5, 15, 30, 60 and 120 min fibrinogen and high molecular weight kininogen (HMWK) adsorption was measured by a newly developed modified ELISA technique. In addition, changes in coagulation and platelet activation were measured by well established assays. High concentrations of fibrinogen were detected after very short blood material contact, both on uncoated as well as heparin-coated tubes. However, high amounts of HMWK were only found on the heparin-bonded surfaces. In addition, the concentrations of the soluble coagulation marker prothrombin fragment F1+2 and the marker for platelet activation beta-thromboglobulin were significantly higher in the non-coated tubes. We presume that adsorption of HMWK to heparin-coated surfaces contributes to the improved hemocompatibility of these bondings.
Wendel
H P
HP
Department of Surgery, Eberhard-Karls University, Tuebingen, Germany. hp.wendel@uni-tuebingen.de
Weber
N
N
Ziemer
G
G
D000327:Adsorption; D004797:Enzyme-Linked Immunosorbent Assay; D005340:Fibrinogen / Q000378:metabolism; D006493:Heparin / Q000378:metabolism*; D006648:Histocompatibility; D006801:Humans; D019679:Kininogen, High-Molecular-Weight / Q000378:metabolism*; D013927:Thrombosis / Q000209:etiology*
D019679:Kininogen, High-Molecular-Weight; D005340:Fibrinogen; D006493:Heparin