Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/81454
Type: Artigo de periódico
Title: Positive inotropic effects of Tityus cambridgei and T. serrulatus scorpion venoms on skeletal muscle
Author: Borja-Oliveira, CR
Pertinhez, TA
Rodrigues-Simioni, L
Spisni, A
Abstract: Toxins that block voltage-dependent K(+) channels and those that modify Na(+) channel gating exhibit positive inotropic effect on skeletal muscle. We compared the effect of the venom of Tityus cambridgei (Tc) and Tityus serrulatus (Ts) scorpions on mouse diaphragm force, in vitro. In indirect and direct (using D-tubocurarine 7.3 mu M) stimulation, Tc, 10 mu g/mL increased the contractile force, an effect prevented by tetrodotoxin (TTX) while Ts, 0.5 mu g/mL, potentiated only indirectly stimulated diaphragm, thus indicating its activity is mainly mediated through acetylcholine release from nerve terminal. This effect is prevented by TTX and attenuated by the K(+) channel opener cromakalim. In conclusion, our data show that while the positive inotropic effect of both venoms appears associated to the activity of Na(+) and K(+) channels, only Tc venom acts also directly on skeletal muscle. This finding call for further studies on Tc venom to identify the toxin responsible for its direct inotropic activity as it may have clinical applications. (C) 2008 Elsevier Inc. All rights reserved.
Subject: Contractile force
Cromakalim
Mouse phrenic nerve-diaphragm
Tetrodotoxin
Tityus serrulatus venom
Country: EUA
Editor: Elsevier Science Inc
Rights: fechado
Identifier DOI: 10.1016/j.cbpc.2008.09.014
Date Issue: 2009
Appears in Collections:Unicamp - Artigos e Outros Documentos

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