The Contrasting Effects of and Venom on Procoagulant Activity and Thrombus Stability under Blood Flow Conditions.

Background: Consumption coagulopathy and hemorrhagic syndrome are the typical features of sp. snake envenoming. In contrast, envenoming can induce thrombotic complications. Our aim was to test whether crude and venoms would display procoagulant activity and induce thrombus formation under flow conditions.

Methods And Principal Findings: Fibrin formation in human plasma was observed for venom at 250-1000 ng/mL concentrations, which also induced clot formation in purified human fibrinogen, indicating thrombin-like activity. The degradation of fibrinogen confirmed the fibrinogenolytic activity of venom. venom displayed consistent thrombin-like and kallikrein-like activity increases in plasma conditions. The well-known procoagulant venom activated plasmatic coagulation factors in vitro and induced firm thrombus formation under high shear rate conditions. In contrast, venom induced the formation of fragile thrombi that could not resist shear stress.

Conclusions: Our results suggest that crude venom displays amidolytic activity and can activate the coagulation cascade, leading to prothrombin activation. venom induces the formation of an unstable thrombus under flow conditions, which can be prevented by the specific monovalent antivenom Bothrofav.