Data/hora: 16/06/2024 06:38:56

Provedor de dados: | 56
País: | Brazil
Título: | Identification of hemolytic and neuroactive fractions in the venom of the sea anemone Bunodosoma cangicum
Autores: | Lagos,P.; Duran,R.; Cerveñansky,C.; Freitas,J.C.; Silveira,R.
Data: | 2001-07-01
Ano: | 2001
Palavras-chave: | Bunodosoma cangicum; Sea anemone; Hemolytic activity; Neurotoxins; Crab nerve.
Resumo: | Sea anemones are a rich source of biologically active substances. In crayfish muscle fibers, Bunodosoma cangicum whole venom selectively blocks the I K(Ca) currents. In the present study, we report for the first time powerful hemolytic and neuroactive effects present in two different fractions obtained by gel-filtration chromatography from whole venom of B. cangicum. A cytolytic fraction (Bcg-2) with components of molecular mass ranging from 8 to 18 kDa elicited hemolysis of mouse erythrocytes with an EC50 = 14 µg/ml and a maximum dose of 22 µg/ml. The effects of the neuroactive fraction, Bcg-3 (2 to 5 kDa), were studied on isolated crab nerves. This fraction prolonged the compound action potentials by increasing their duration and rise time in a dose-dependent manner. This effect was evident after the washout of the preparation, suggesting the existence of a reversible substance that was initially masking the effects of an irreversible one. In order to elucidate the target of Bcg-3 action, the fraction was applied to a tetraethylammonium-pretreated preparation. An additional increase in action potential duration was observed, suggesting a blockade of a different population of K+ channels or of tetraethylammonium-insensitive channels. Also, tetrodotoxin could not block the action potentials in a Bcg-3-pretreated preparation, suggesting a possible interaction of Bcg-3 with Na+ channels. The present data suggest that B. cangicum venom contains at least two bioactive fractions whose activity on cell membranes seems to differ from the I K(Ca) blockade described previously.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000700009
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2001000700009
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.34 n.7 2001
Fonte: | info:eu-repo/semantics/openAccess