Snake venom toxins are now regularly used in the coagulation laboratory for assaying haemostatic parameters and as coagulation
reagents.
Snake venom thrombin-like
enzymes (SVTLE) are used for
fibrinogen and
fibrinogen breakdown product assay as well as detecting dysfibrinogenaemias. Significantly, because SVTLE are not inhibited by
heparin, they can be used for defibrinating samples that contain the
anticoagulant before assay of haemostatic variables.
Prothrombin activators are found in many
snake venoms and are used in
prothrombin assays, for studying dysprothrombinaemias and preparing
meizothrombin and non-enzymic
prothrombin. Russell's viper (Daboia russelli)
venom (RVV) contains a number of compounds useful in the assay of factors V, VII, X,
platelet factor 3 and lupus
anticoagulants. Activators from the taipan, Australian brown snake and saw-scaled viper have been used to assay lupus
anticoagulants.
Protein C and
activated protein C resistance can be measured by means of RVV and
Protac, a fast acting inhibitor from Southern copperhead
snake venom and
von Willebrand factor can be studied with
Botrocetin from
Bothrops jararaca venom. Finally,
phospholipase A2 enzymes and the
disintegrins, a family of
Arg-Gly-Asp (RGD)-containing
proteins found in
snake venoms, show great potential for the study of haemostasis including, notably,
platelet glycoprotein receptors GPIIb/IIIa and Ib.