Action of heparin and acetylcholine modulators on the neurotoxicity of the toad Rhinella schneideri (Anura: Bufonidae) in Brazil

Autor(es)

Rostelato-Ferreira, Sandro ^{[1, 2]} ; Vettorazzo, Orlando B. ^[1] ; Tribuiani, Natalia ^[1] ; Leal, Allan P. ^[3] ; Dal Belo, Chariston A. ^{[3, 4]} ; Rodrigues-Simioni, Lea ^[5] ; Floriano, Rafael S. ^[6] ; Oshima-Franco, Yoko ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sorocaba UNISO, Grad Program Pharmaceut Sci, Sorocaba, SP - Brazil

^[2] Paulista Univ UNIP, Inst Hlth Sci, Sorocaba, SP - Brazil

^[3] Fed Univ Santa Maria UFSM, Grad Program Toxicol Biochem, Santa Maria, RS - Brazil

^[4] Fed Univ Pampa UNIPAMPA, Lab Neurobiol & Toxinol Lanetox, Sao Gabriel, RS - Brazil

^[5] Univ Estadual Campinas, UNICAMP, Fac Med Sci, Dept Pharmacol, BR-13083970 Campinas, SP - Brazil

^[6] Univ Western Sao Paulo UNOESTE, Grad Program Hlth Sci, Presidente Prudente, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Revista de Biología Tropical; v. 69, n. 2, p. 545-556, APR-JUN 2021.
• Citações Web of Science: 0

Resumo

Introduction: Rhinella schneideri is a toad widely distributed in South America and its poison is characterized by inducing cardiotoxicity and neurotoxicity. Objective: In this work, we investigated pharmacological strategies to attenuate the peripheral neurotoxicity induced by R. schneideri poison in avian neuromuscular preparation. Methods: The experiments were carried out using isolated chick biventer cervicis preparation subjected to field stimulation for muscle twitches recordings or exposed to acetylcholine and potassium chloride for contracture responses. Results: Poison (10 mu g/ml) produced complete neuromuscular blockade in chick biventer cervicis preparation within approximately 70 min incubation (times for 50 and 90 % blockade: 15 +/- 3 min and 40 +/- 2 min, respectively; P < 0.05, N = 5); contracture responses to exogenous acetylcholine and KCl were unaffected by poison indicating no specificity with postsynaptic receptors or myotoxicity, respectively. Poison (10 mu g/ml)induced neuromuscular blockade was not prevented by heparin (5 and 150 IU/ml) under pre- or post-treatment conditions. Incubation at low temperature (23-25 degrees C) abolished the neuromuscular blockade; after raising the temperature to 37 degrees C, the complete neuromuscular blockade was slightly slower than that seen in preparations directly incubated at 37 degrees C (times for 50 and 90 % blockade: 23 +/- 2 min and 60 +/- 2.5 min, respectively; P < 0.05, N = 4). Neostigmine (3.3 mu M) did not reverse the neuromuscular blockade in BC preparation whereas 3,4-diaminopyridine (91.6 mu M) produced a partial and sustained reversal of the twitch responses (29 +/- 7.8 % of maximal reversal reached in approximately 40 min incubation; P < 0.05, N = 4). Conclusions: R. schneideri poison induces potent peripheral neurotoxicity in vitro which can be partially reversible by 3,4-diaminopyridine. (AU)

• Processo FAPESP: 12/08271-0 - IDENTIFICAÇÃO E FARMACODINÂMICA DE FRAÇÕES NEUROFACILITADORAS DA Casearia sylvestris SW. NA JUNÇÃO NEUROMUSCULAR
• Beneficiário: Yoko Oshima Franco
• Modalidade de apoio: Auxílio à Pesquisa - Regular