Haemorrhagic and permeability increasing effects of 'Bothrops jararaca' and other Crotalidae venoms as related to amine or kinin release.

Abstract

The venom ‘Bothrops jararaca’ anda high molecular weight fraction obtained from it induced vasculotoxic effects when applied on the exposed surface of the lung of the dog and increased the vascular permeability when injected into the rat skin. These effects were compared to those evoked by other venoms and potential mediators. The increase in vessel permeability due to ‘B. jararaca’ venom was feebly affected by antiserotonin and antihistamine agents and was presumably due to kinin release. The effect on the lung surface was related to the coagulant and necrogenic properties of the venom and was suppressed by EDTA, promethazine and specific antiserum. A kinin releasing enzyme extracted from the venom increased the vascular permeability but had no effect on the lung. Venoms from ‘Crotalus adamanteus’ and from ‘Crotalus durissus terrificus’ also increased the vascular permeability, but were inhibited by antihistamine/antiserotonin agents; this blockade uncovered a marked skin hemorrhagic effect due to ‘Crotalus adamanteus’. Despite this activity, no vasculotoxic effect was found when ‘Crotalus adamanteus’ venom was applied to the lung. Effects of the tested venoms and enzymes are highly specific for either vascular bed, depending upon the availability on the challenged sites of different tissue components and on the specific properties of the venoms.