Fibrin Formation and Proteolysis during Ancrod Treatment
Ancrod is a purified fraction of venom from the Malayan pit viper Calloselasma rhodostoma, containing a serine protease that cleaves fibrinopeptides A from fibrinogen. We report on a study that involved intravenous and subcutaneous application of ancrod in healthy subjects in which it was shown that ancrod induces the formation of desAA-fibrin complexes that are partially crosslinked by factor XIII proenzyme, and act as cofactor in tPA induced plasminogen activation. The plasmin generated degrades fibrin, as well as fibrinogen, leading to the appearance of large amounts of fibrinogen and fibrin degradation products in the circulation, including fragment D-dimer. At low concentrations of ancrod, formation of desAA-fibrin is preceded by production of desA-profibrin, lacking only one fibrinopeptide A.
fibrin formation proteolysis ancrod factor xiii desa-profibrin