No abstract

Heparins, as anticoagulants widely used in the prophylaxis and treatment of many conditions connected with hypercoagulability, have a potent effect on the vascular endothelium. Unfractionated Heparin (UFH) is characterized by relatively low biological accessibility, short activity time, binding of numerous proteins, as well as unfavorable influence on endothelium and blood platelets. Low-Molecular Weight Heparins (LMWHs), formed by chemical and enzymatic UFH depolymerizations, show a significantly more favorable impact on endothelium, which was confirmed on the HUVEC cultures study models. The studies on the heparins' modulation of angiogenesis process proved the superiority of LMWHs over UFH. It was connected with a better deactivation of growth factors' receptors (e.g. for VEGF165, FGF-2). Comparing the effects of LMWHs and UFH on haemostatic and antiangiogenic properties of HUVEC, significant differences were found as well. A new effect, engaging these compounds in the pathomechanism of an excessive osteoclastogenesis via osteoprotegerin /RANKL/RANK pathway has been discovered recently.