Ability of six Latin American antivenoms to neutralize the venom of Mapana equis (Bothrops atrox) from Antioquia and Chocó (Colombia)
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文摘
Variability in snake venoms can be due to (1) the variation in concentration of the different fractions of the venom, or (2) the composition of proteins, which alters their pharmacological or immunological properties. The origin of these variations seems to be genetic. We studied the venom of members of litters born in a snake farm (42 Crotalus atrox and 21 Naja haje). We first used electrophoresis in cellulose acetate (AE). Then, variations were confirmed by immunoelectrophoresis (AE) using an antivenom (Ipser Afrique®, Pasteur Mérieux Sérums and Vaccins) and immunsera prepared on rabbit from (1) venom presenting the maximum of bands in electrophoresis (complete venom), and (2) pure toxins (neurotoxin-α and cardiotoxin-γ). The AE of C. atrox venoms showed a good homogeneity, probably due to a good genetic stability of the investigated group. In contrast, N. haje venoms have revealed a great heterogeneity. The 21 samples were allocated to five groups according to the absence of some fractions compared to the complete venom. The AE showed that the neurotoxin-α is present in every sample, but variable in quantity, even when it did not appear on AE. It was not possible to specify whether these pattern variations were due to artefacts linked to relative variations of protein fractions in samples or whether that corresponded to a modification of the chemical composition of the neurotoxin-α. However, the variation in toxicity between the different samples questioned the neutralization ability of antivenoms.