Glutamate induces glutathione efflux mediated by glutamate/aspartate transporter in retinal cell cultures.

T B Garcia, K R M Oliveira, J L M do Nascimento, M E Crespo-López, D L W Picanço-Diniz, T C Mota, A M Herculano

Laboratório de Neuroendocrinologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus do Guamá, Av. Augusto Corrêa, 01, Belém, Pará, 66075-900, Brazil.

Neurochemical research 2011 Mar

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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.

Citation

T B Garcia, K R M Oliveira, J L M do Nascimento, M E Crespo-López, D L W Picanço-Diniz, T C Mota, A M Herculano. Glutamate induces glutathione efflux mediated by glutamate/aspartate transporter in retinal cell cultures. Neurochemical research. 2011 Mar;36(3):412-8