ABSTRACT
Botrocetin was originally named venom coagglutinin (VCA) when it was discovered in 1978. It is one of many venom factors that has been described in recent years that cause platelet aggregation or platelet agglutination. The design of survey studies for the presence of botrocetin in venoms requires a test system in which botrocetin causes agglutination of platelets in the presence of von Willebrand factor, but no agglutination in the absence of von Willebrand factor (VWF). Bothrops jararaca venom has served as the source of botrocetin for its isolation. The crude venom possesses not only the botrocetin platelet-aggregating activity but also fibrinogen-clotting activity owing to the presence of a thrombinlike enzyme. Botrocetin administration to animals results in thrombocytopenia and altered levels of circulating plasma VWF. The action of botrocetin in causing platelet aggregation is mediated through two essential components of the blood, VWF and the platelet membrane receptor glycoprotein receptor lb, IX.
