Properties of in vitro nonenzymatically glycated plasma fibrinogens.

Nonenzymatic glycation of fibrinogen is species independent and depends only on the glucose concentration in the incubation mixture under selected in vitro conditions. An increased fibrin monomer aggregation in the presence of Ca2+ ions and a decreased proteolytic susceptibility of nonenzymatically glycated fibrinogens may favour the development of thrombophilic states. Blocking of lysine residues as well as restricted conformational changes induced by glucose attachment may be responsible for these effects. Fibrin stabilization by factor XIII is not impaired by nonenzymatic glycation of fibrinogen. Attachment of aortic endothelial cells to fibrin films from glycated fibrinogens is diminished. This phenomenon may be the result of blocked plasminogen activator binding sites in fibrin by nonenzymatic glycation. These effects may contribute in vivo to the accumulation of fibrin in those tissues most frequently affected by diabetic complications.