Modulation of the mammalian coagulation system by venoms and other proteins from snakes, arthropods, nematodes and insects.

The mammalian hemostatic system involves complex interactions between protein components of the coagulation cascade and platelets. The fibrinolytic system removes the hemostatic plug. Dysregulation of coagulation or fibrinolytic systems can induce bleeding or thrombosis. Animals, such as snakes, worms and insects, have evolved to express proteins that modulate the mammalian coagulation and fibrinolytic systems. Many of these proteins have been isolated and characterized. Understanding the mechanisms by which these exogenous factors from venoms and animal saliva modulate the mammalian coagulation and fibrinolytic systems has led to a better understanding of these systems. Furthermore, some of these exogenous proteins are used in diagnostic assays and as therapeutic drugs. This review summarizes our current knowledge of exogenous proteins from venom and saliva that either activate or inhibit the mammalian coagulation and fibrinolytic systems.