SBNeC 2010
Resumo:B.075


Poster (Painel)
B.075Sub chronic caffeine administration affects glutamate uptake and its transporters immunocontent in rat hippocampal slices
Autores:Gabriela Tondolo Fioreze (UFRGS - Universidade Federal do Rio Grande do Sul) ; Marcelo Silveira Costa (UFRGS - Universidade Federal do Rio Grande do Sul) ; Gabriele Cordenonzi Ghisleni (UFRGS - Universidade Federal do Rio Grande do Sul) ; Diogo Onofre Gomes de Souza (UFRGS - Universidade Federal do Rio Grande do Sul) ; Lisiane de Oliveira Porciúncula (UFRGS - Universidade Federal do Rio Grande do Sul)

Resumo

Glutamate is the major excitatory neurotransmitter being removed from the synaptic cleft by neuronal and astroglial transporters after exert its neurotransmission. In vitro studies have shown that caffeine can trigger facilitation of glutamate release in isolated synaptossomes but studies investigating the effects of caffeine on glutamate transporters are still lacking. The objective of this study was to investigate the effect of caffeine administration on functionality and density of glutamate transporters. For this, hippocampal slices from Wistar rats treated with saline (0.9 g%, i.p) or caffeine (10 mg / kg, ip) for 1, 3, 15 or 30 days were examined for glutamate uptake and immunocontent glial (GLAST and GLT-1), neuronal (EAAC1) and vesicular (VGLUT-1) transporters. Glutamate uptake was decreased in hippocampal slices from rats treated for 3 and 15 days with caffeine (42% and 30%, respectively). Caffeine administration for 15 days caused a decrease in EAAC1 (35%) and GLAST (25%) whereas GLT-1 immunocontent increased by 25%. The immunocontent of VGLUT-1 decreased in hippocampal slices from rats treated with caffeine for 1, 3 and 15 days (25%, 20% and 15%, respectively). These findings showed that caffeine administered in a safe dose affects glutamate transporters. It can be suggested that the psychostimulant effects of caffeine may also involves modification on glutamatergic neurotransmission beyond the antagonism of adenosine receptors.


Palavras-chave:  Caffeine, Glutamate uptake, Hippocampal