| Texto completo | |
| Autor(es): Mostrar menos - |
Couceiro, Fernanda Y. G. M.
;
Demico, Poliana J.
;
Dias, Samuel R.
;
Oliveira, Isabele N.
;
Pacagnelli, Francis L.
;
Silva, Elisangela O.
;
Sant'Anna, Savio S.
;
Grego, Kathleen F.
;
Morais-Zani, Karen
;
Torres-Bonilla, Kristian A.
;
Hyslop, Stephen
;
Floriano, Rafael S.
Número total de Autores: 12
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Toxicon; v. 234, p. 8-pg., 2023-10-01. |
| Resumo | |
In this work, we examined the neuromuscular blockade caused by venoms from four South-American coralsnakes (Micrurus altirostris - MA, M. corallinus - MC, M. spixii - MS, and M. dumerilii carinicauda - MDC) and the ability of varespladib (VPL), a phospholipase A2 (PLA2) inhibitor, to attenuate this blockade. PLA2 activity was determined using a colorimetric assay and a fixed amount of venom (10 mu g). Neurotoxicity was assayed using a single concentration of venom (10 mu g/ml) in mouse phrenic nerve-diaphragm (PND) preparations mounted for myographic recordings and then subjected to histological analysis. All venoms showed PLA2 activity, with MS and MA venoms having the highest (15.53 +/- 1.9 A425 nm/min) and lowest (0.23 +/- 0.14 A425 nm/min) activities, respectively. VPL (292 and 438 mu M) inhibited the PLA2 activity of all venoms, although that of MA venom was least affected. All venoms caused neuromuscular blockade, with MS and MDC venoms causing the fastest and slowest 100% blockade [in 40 +/- 3 min and 120 +/- 6 min (n = 4), respectively]; MA and MC produced complete blockade within 90-100 min. Preincubation of venoms with 292 mu M VPL attenuated the blockade to varying degrees: the greatest inhibition was seen with MDC venom and blockade by MS venom was unaffected by this inhibitor. These results indicate that PLA2 has a variable contribution to coralsnake venom-induced neuromuscular blockade in vitro, with the insensitivity of MS venom to VPL suggesting that blockade by this venom is mediated predominantly by post-synaptically-active alpha-neurotoxins. (AU) | |
| Processo FAPESP: | 20/04287-6 - Caracterização estrutural e farmacológica de toxinas isoladas do veneno de Bothrops bilineatus smaragdinus (víbora de floresta) com potencial atividade moduladora da liberação sináptica motora e de funções cardiovasculares |
| Beneficiário: | Rafael Stuani Floriano |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa BIOTA - Regular |
| Processo FAPESP: | 20/07268-2 - Caracterização do perfil coagulotóxico de venenos de serpentes da família Viperidae de importância médica no Brasil |
| Beneficiário: | Karen de Morais Zani |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 23/01961-6 - Ação antagonista de marimastat, um peptídeo sintético inibidor de metaloprotease, sobre os efeitos miotóxico, hemorrágico e coagulante do veneno de Lachesis muta muta (Surucucu Sul-Americana) em roedores |
| Beneficiário: | Isabele Nascimento Oliveira |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |
| Processo FAPESP: | 22/05878-3 - Avaliação da ação enzimática, neuromuscular e hemostática do veneno de Crotalus durissus ruruima (Viperidae: Crotalinae) e neutralização por antiveneno comercial |
| Beneficiário: | Poliana de Jesus Demico |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |