PnTx3-6 a spider neurotoxin inhibits K+-evoked increase in [Ca2+](i) and Ca2+-dependent glutamate release in synaptosomes.
Neurochem Int
; 42(4): 277-82, 2003 Mar.
Article
em En
| MEDLINE
| ID: mdl-12470700
ABSTRACT
The present experiments investigated the effect of a neurotoxin purified from the venom of the spider Phoneutria nigriventer. This toxic component, P. nigriventer toxin 3-6 (PnTx3-6), abolished Ca(2+)-dependent glutamate release with an IC(50) of 74.4nM but did not alter Ca(2+)-independent secretion of glutamate when brain cortical synaptosomes were depolarized by KCl (33mM). This effect was most likely due to interference with the entry of calcium through voltage activated calcium channels (VACC), reducing the increase in the intrasynaptosomal free calcium induced by membrane depolarization with an IC(50) of 9.5nM. We compared the alterations induced by PnTx3-6 with the actions of toxins known to block calcium channels coupled to exocytosis. Our results indicate that PnTx3-6 inhibition of glutamate release and intrasynaptosomal calcium involves P/Q type calcium channels and this toxin can be a valuable tool in the investigation of calcium channels.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Sinaptossomos
/
Neuropeptídeos
/
Bloqueadores dos Canais de Cálcio
/
Cálcio
/
Ácido Glutâmico
Limite:
Animals
Idioma:
En
Revista:
Neurochem Int
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Brasil