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Type: | Artigo de periódico |
Title: | Biophysical, histopathological and pharmacological characterization of crotamine isoforms F22 and F32 |
Author: | Toyama, MH Marangoni, S Novello, JC Leite, GB Prado-Franceschi, J da Cruz-Hofling, MA Rodrigues-Simioni, L |
Abstract: | Two major crotamine isoforms (F22 and F32) were obtained after three chromatographic steps and were assayed in mouse phrenic nerve-diaphragm preparations. F32 and F22 (0.5 mug/ml, n = 4) produced a facilitatory effect, which increased isometric twitch-tension by 300 and 230%, respectively, after a 120 min incubation. At a concentration of 0.1 mug/ml, both isoforms increased the twitch-tension by about 160%. However, when the isoforms were co-incubated (final concentration, 0.5 mug/ml) for 30 min prior to testing, they did not cause the facilitation seen with greater than or equal to0.1 mug/ml of each isoform alone. Histologically, F32 and F22 at 0.5 and 1 mug/ml were quantitatively alike in inducing tissue myonecrosis. However, a mixture of the two isoforms (final concentration, 0.5 mug/ml) significantly attenuated the damage seen with either toxin alone. Mass spectrometry analysis showed that the isoforms had the same molecular mass (4.8 kDa) and that they existed as monomers with a highly stable structure. These results indicate that F22 and F32 acted on muscle cells of the mouse phrenic-nerve diaphragm preparation through similar mechanisms. Since the isoforms did not produce the expected summation in the increase in muscle twitch-tension, it is possible that they may have different affinities for the sodium channel subunits. (C) 2003 Elsevier Science Ltd. All rights reserved. |
Subject: | Crotalus durissus terrificus crotamine HPLC myotoxin rattlesnake venom |
Country: | Inglaterra |
Editor: | Pergamon-elsevier Science Ltd |
Citation: | Toxicon. Pergamon-elsevier Science Ltd, v. 41, n. 4, n. 493, n. 500, 2003. |
Rights: | fechado |
Identifier DOI: | 10.1016/S0041-0101(02)00390-2 |
Date Issue: | 2003 |
Appears in Collections: | Unicamp - Artigos e Outros Documentos |
Files in This Item:
File | Description | Size | Format | |
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WOS000182308300011.pdf | 416.68 kB | Adobe PDF | View/Open |
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