Data/hora: 01/06/2024 07:40:18

Provedor de dados: | 80
País: | Brazil
Título: | Inhibition of L-glutamate and GABA synaptosome uptake by crotoxin, the major neurotoxin from Crotalus durissus terrificus venom
Autores: | Cecchini,A.L.; Soares,A.M.; Giglio,J.R.; Amara,S.; Arantes,E.C.
Data: | 2004-01-01
Ano: | 2004
Palavras-chave: | Crotoxin; L-glutamate; GABA; Crotalus durissus terrificus.
Resumo: | This paper describes a brief study on the crotoxin mechanism of action, regarding the transport of GABA and L-glutamate in rats cortico-cerebral synaptosomes and in heterologous systems, such as COS-7 cells expressing gabaergic transporters, and C6 glioma cells and Xenopus oocytes expressing glutamatergic transporters. Crotoxin concentrations over 1 µM caused an inhibitory effect of ³H-L-glutamate and ³H-GABA, and reversibly inhibited L-glutamate uptake by C6 glioma cells. When COS-7 cells were assayed, no inhibition of the ³H-GABA transport could be evidenced. Crotoxin kept its inhibitory effect on neurotransmitters uptake even when Ca2+ ions were removed from the medium, therefore, independently of its PLA2 activity. In addition, high concentrations (2 mM) of BPB did not avoid the action of crotoxin on the neurotransmitters uptake. Crotoxin also inhibited ³H-L-glutamate, independently on Na+ channel blockade by TTX. In addition, an evaluation of the lactic dehydrogenase activity indicated that uptake inhibition does not involve a hydrolytic action of crotoxin upon the membrane. We may also suggest that crotoxin acts, at least partially, altering the electrogenic equilibrium, as evidenced by confocal microscopy, when a fluorescent probe was used to verify cell permeability on C6 glioma cells in presence of crotoxin.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992004000300006
Editor: | Centro de Estudos de Venenos e Animais Peçonhentos
Relação: | 10.1590/S1678-91992004000300006
Formato: | text/html
Fonte: | Journal of Venomous Animals and Toxins including Tropical Diseases  v.10 n.3 2004
Fonte: | info:eu-repo/semantics/openAccess