The coagulation of blood by snake venoms and its physiologic significance

Abstract

Nine of the 17 venoms here tested were found capable of coagulating citrated blood or plasma. As has been believed by most workers in the field, 7 of these 9 coagulant venoms convert fibrinogen to an insoluble modification resembling fibrin (Bothrops atrox, Bothrops jararaca, Bothrops nummifera, Crotalus adamanteus, Crotalus horridus, Crotalus terrificus basitiscus, Crotalus terrificus terrificus). The optimum pH for this coagulation was determined for 3 of these, and was found in each case to be approximately pH 6.5, the same as that for the action of thrombin on fibrinogen. Unlike thrombin, however, the fibrinogen-coagulating activity of the venoms was unaffected by the antithrombin elaborated in the course of anaphylactic shock. © 1937, Rockefeller University Press., All rights reserved.