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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Author(s):
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]
Total Authors: 8
Affiliation:
[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
Total Affiliations: 6
Document type: Journal article
Source: Revista de Biología Tropical; v. 69, n. 2, p. 545-556, APR-JUN 2021.
Web of Science Citations: 0
Abstract

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)

FAPESP's process: 12/08271-0 - IDENTIFICATION AND PHARMACODYNAMIC OF NEUROFACILITATING FRACTIONS OF Casearia sylvestris SW. AT THE NEUROMUSCULAR JUNCTION
Grantee:Yoko Oshima Franco
Support Opportunities: Regular Research Grants