The role of fibronectin in hemostasis

Over the past 10-15 years, researchers in the field of experimental and clinical medicine have shown increased interest in fibronectin —FN), a blood plasma protein with a diverse biological effect. FN is a glycoprotein found both in the blood and in other body fluids, and in an insoluble form - in connective tissue, in particular as part of the basement membrane [28, 30, 48, 69]. The main source of plasma FNL are endothelial cells and hepatocytes. FN ensures the convergence and adhesion of cells, contributing to the elimination of vascular endothelial defect in normal condition and after injury. Its molecular weight is about 4.4-105 daltons, the sedimentation constant is 12-14S, the isoelectric point is 5.5-6.2; it belongs to the class of mobile β-globulins [44c]. The function of this protein in the human body is diverse. This can be judged, in particular, by the number of available synonyms, each of which reflects a certain biological property of the protein: cold-insoluble globulin, anti-gelatin factor, microfibrillary protein, protein with opsonin properties, fibroblast surface antigen, galactoprotein a, cell attachment factor, large external transformation-sensitive protein, cell surface protein, cell proliferation factor [28, 64]. The preferred term is "fibronectin", which means "fiber binding" (from Lat. fibra- fiber-nectere - binding) [23, 30, 41]. Plasma FN together with fibrinogen, factor XIII, and Willebrand factor is precipitated from plasma at 0° 25% with ammonium sulfate [44a] or 8% ethanol [43]. Its concentration in the cryoprecipitate increases 5-10 times [43], in the plasma of healthy men is 180-720 mg / l, in women - 150-540 mg / l, in serum - 20-50% less than in plasma.