Hemorrhagic Snake Venoms and Kallikrein Inhibitors as Tools to Study Factors Determining the Integrity of the Vessel Wall

Abstract

Hemorrhagic snake venoms contain a multitude of factors which either through a direct action or indirectly through the release of some mediator disturb the integrity of the vessel wall. For example the protease and/or esterase components in some of such venoms are enzymes known to release polypeptide kinins, which are considered as one of the mediators of microvascular functional disturbances. Previously we developed a method (4,5), which allows to study quantitatively the hemorrhagic effect of snake venoms on pulmonary surface vessels. The venom of Agkistrodon piscivorus is recognized to contain a kinin releasing component (10). We therefore examined the hemorrhagic action of this venom under the influence of some compounds which interfere with the kallikrein-kinin system. The effect of the same compounds were also studied on the hemorrhagic action of Naja naja venom, which is not known to release kinins and from which we have shown that its hemorrhagic effect is dependent on its content of a basic polypeptide (5), the latter unlikely to possess protease or esterase activity (6).