title: On the mechanism of enhanced thromboresistance of polymeric materials in the presence of heparin.
abstract: Polymeric materials with covalently immobilized heparin were shown to display enhanced thromboresistance in vitro and in vivo experiments. This property of heparin-containing polymers is due to the specific effect of immobilized heparin for every step of interaction of a polymer with blood. The presence of heparin substantially changes the character of adsorbed proteins on a polymer surface and the number of adhered platelets. Thromboresistance enhancement is largely carried out by the interaction of immobilized heparin with plasma proteins which is accompanied by the decrease in total blood coagulant activity, by the decrease in fibrinogen, prothrombin and thrombin concentrations, and by the supression of fibrinstabilizing factor activity. The free heparin content in blood is not changed. It was found that immobilized heparin forms complexes with fibrinogen, thrombin and plasmin that produce lytic action on unstabilized fibrin.
mesh_terms: D000327:Adsorption; D000818:Animals; D000990:Antithrombin III / Q000378:metabolism; D001777:Blood Coagulation / Q000187:drug effects; D001798:Blood Proteins / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology*; D066298:In Vitro Techniques; D010973:Platelet Adhesiveness; D011108:Polymers / Q000494:pharmacology*; D011817:Rabbits; D013927:Thrombosis / Q000517:prevention & control*
chemical_list: D001798:Blood Proteins; D011108:Polymers; D000990:Antithrombin III; D006493:Heparin