Presynaptic Activity of an Isolated Fraction from Rhinella schneideri Poison

Autor(es)

Rostelato-Ferreira, Sandro ^{[1, 2]} ; Dal Belo, Chariston Andre ^[3] ; da Silva Junior, Pedro Ismael ^[4] ; Hyslop, Stephen ^[1] ; Rodrigues-Simioni, Lea ^[1] ; Alves Rocha-e-Silva, Thomaz Augusto ^[5]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas UNICAMP, Dept Farmacol, Fac Ciencias Med, BR-13083970 Campinas, SP - Brazil

^[2] Univ Paulista UNIP, Inst Ciencias Saude, BR-18087101 Sorocaba, SP - Brazil

^[3] Univ Fed Pampa UNIPAMPA, Ctr Ciencias Rurais Sao Gabriel, Sao Gabriel, RS - Brazil

^[4] Inst Butantan, Lab Especial Toxinol Aplicada, Sao Paulo, SP - Brazil

^[5] Fac Israelita Ciencias Saude Albert Einstein, Sch Med, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ADVANCED PHARMACEUTICAL BULLETIN; v. 8, n. 3, p. 517-522, 2018.
• Citações Web of Science: 1

Resumo

Purpose: Rhinella schneideri is a toad found in many regions of the South America. The poison of the glands has cardiotoxic effect in animals and neuromuscular effects in mice and avian preparation. The purpose of this work was to identify the toxin responsible for the neuromuscular effect in avian and mice neuromuscular preparation. Methods: The methanolic extract from R. schneideri poison was fractioned by reversed phase HPLC. The purity and molecular mass were determined by LC/MS mass spectrometry. Chick biventer cervicis and mouse phrenic-nerve diaphragm were used as neuromuscular preparations to identify the toxin. Results: The purification resulted in 32 fractions, which 4 of them were active in neuromuscular preparation. The toxin of fraction 20 were chosen for better reproducibility of the whole extract activity and its molecular mass was 730.6 Da. The toxin produced facilitation of the muscle contraction followed by a complete neuromuscular blockade in chick biventer cervicis preparation in 90 min without interfering with the exogenous response to ACh and KCl. The quantal content was increased from 128 +/- 13 (control) to 216 +/- 44 (after 5 min and sustained until 60 min) in the presence of the toxin. Conclusion: In conclusion, our results demonstrated that the neuromuscular action of the poison of Rhinella schneideri is a multitoxin effect. More, the present work first isolated a 730.6 Da toxin that better represent the whole poison neuromuscular effect, to which is attributed a presynaptic action in avian and mouse neuromuscular preparation. (AU)

• Processo FAPESP: 08/54050-0 - Estudo da atividade de peçonhas nao-ofidicas na junção neuromuscular
• Beneficiário: Lea Rodrigues Simioni
• Linha de fomento: Auxílio à Pesquisa - Regular