Comparação da atividade paralisante de peçonhas e Crotoxinas isoladas de serpentes da subespécie Crotalus durissus terríficus de diferentes regiões do estado de Minas Gerais.

Abstract

Several studies show the existence of variations in the composition and effects of venoms from different subspecies of Crotalus snakes, or even from the same subspecies. Considering the lethality of crotalic poisoning, the comparative study of the biological activities of venoms and its main toxic component, Crotoxin (CTX), can provide subsidies for the development of a more effective antiophidic therapy, in addition to advancing the knowledge of the mechanism of action of these compounds. Thus, the aim of this study was to compare, through myographic and morphological techniques, the neuromuscular blocking activity and the general morphological aspect of muscles exposed to venoms and CTXs isolated from Crotalus durissus terrificus snakes, from different regions of the Minas Gerais state (Carrancas, Patos de Minas, Nova Ponte and Nazareno). Venoms and CTXs were tested in mouse phrenic nerve-diaphragm preparations. The results showed a time and concentration-dependent blockade of neuromuscular preparations exposed to venoms and CTXs in 180 minutes. Differences were observed at the concentration of 1 μg/mL, for both substances, revealing possible variations in venom composition as well as in CTX isoforms. The morphological study revealed the myotoxic capacity of venoms and CTXs, however, despite the differences in relation to the control group, there was no variation between the venom or CTXs groups. From the results obtained, we can conclude the importance of functional proof of the variability between venoms and toxins from the same subspecies, revealing the need for venom pools, from different regions, for the production of antivenoms.