title: Antithrombin-independent effects of heparins on fibrin clot nanostructure.
abstract: OBJECTIVE
  Because of the widespread clinical use of heparins, their effects on the enzymatic cascade are very well known. In contrast, little is known about the direct effect of heparins on the nanostructure of fibrin fibers, even though this nanostructure plays a major role in the mechanical strength and lysis of clots. This lack of reliable data can be correlated with the lack of a nonintrusive, quantitative method to determine this structure. We recently developed such a method that allows the simultaneous determination of the average fiber radius and the protein content using spectrometric data. In this study, we assessed the nanostructure of fibrin in a system composed of human thrombin and fibrinogen.
  
  
  RESULTS
  We provide quantitative evidence showing that both unfractionated heparin and low molecular weight heparin directly alter the nanostructure of fibrin fibers independent of their other actions on the coagulation cascade; as expected, the pentasaccharide fondaparinux has no effect.
  
  
  CONCLUSIONS
  Our results show that in addition to the effect of heparin on the coagulation cascade, modifications of the fibrin nanostructure may also contribute to improved fibrinolysis.
authors.affiliation: Laboratoire de Rhéologie, CNRS UMR5520, Université Joseph Fourier, Grenoble, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Yeromonahos
authors.forename: Raphaël
authors.initials: R
authors.lastname: Marlu
authors.forename: Benoît
authors.initials: B
authors.lastname: Polack
authors.forename: Francois
authors.initials: F
authors.lastname: Caton
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects*; D005337:Fibrin / Q000737:chemistry / Q000648:ultrastructure*; D005340:Fibrinogen / Q000378:metabolism*; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D013053:Spectrophotometry; D013917:Thrombin / Q000378:metabolism*; D013927:Thrombosis / Q000097:blood* / Q000188:drug therapy / Q000473:pathology
chemical_list: D005343:Fibrinolytic Agents; D005337:Fibrin; D005340:Fibrinogen; D006493:Heparin; D013917:Thrombin