title: Glutamate induces glutathione efflux mediated by glutamate/aspartate transporter in retinal cell cultures.
abstract: This study was undertaken in order to characterize the role of the glutamate/aspartate transporter (GLAST) in the glutathione (GSH) efflux induced by glutamate. Our results demonstrated that retinal cell cultures exhibit two mechanisms of GSH release, one Na(+)-independent and other Na(+)-dependent. Glutamate and aspartate induced GSH efflux only in presence of Na(+). Treatment with PCD (L-trans-Pyrrolidine-2,4-dicarboxylate), a transportable glutamate uptake blocker, increased GSH release indicating that GSH can be carried by glutamate transporters in retinal cell cultures. Added to this, treatment with zinc ion cultures, a recognized inhibitor of GLAST blocked GSH efflux evoked by glutamate. Treatment with NMDA antagonist (MK-801) did not have any effect on the GSH release induced by glutamate. These results suggest that glutamate induces GLAST-mediated release of GSH from retinal cell cultures and this could represent an important mechanism of cellular protection against glutamate toxicity in the CNS.
authors.affiliation: Laboratório de Neuroendocrinologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus do Guamá, Av. Augusto Corrêa, 01, Belém, Pará, 66075-900, Brazil.
authors.forename: T B
authors.initials: TB
authors.lastname: Garcia
authors.forename: K R M
authors.initials: KR
authors.lastname: Oliveira
authors.forename: J L M
authors.initials: JL
authors.lastname: do Nascimento
authors.forename: M E
authors.initials: ME
authors.lastname: Crespo-López
authors.forename: D L W
authors.initials: DL
authors.lastname: Picanço-Diniz
authors.forename: T C
authors.initials: TC
authors.lastname: Mota
authors.forename: A M
authors.initials: AM
authors.lastname: Herculano
mesh_terms: D027322:Amino Acid Transport System X-AG / Q000378:metabolism*; D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D002478:Cells, Cultured; D002642:Chick Embryo; D003998:Dicarboxylic Acids / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism*; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D012160:Retina / Q000166:cytology* / Q000187:drug effects
chemical_list: D027322:Amino Acid Transport System X-AG; D003998:Dicarboxylic Acids; D014179:Neurotransmitter Uptake Inhibitors; D011759:Pyrrolidines; D001224:Aspartic Acid; D018698:Glutamic Acid; C083486:pyrrolidine-2,4-dicarboxylic acid; D005978:Glutathione