LONG-TERM treatment of astrocytes in primary culture with L-glutamate (0.1-3 mM) resulted in a dose-dependent increase in D-[H-3]aspartate uptake. The effect was abolished by an antagonist of kainate/AMPA receptors, CNQX, and mimicked by kainate, but not by AMPA or tACPD. Both glutamate and kainate caused a dramatic up-regulation (82% and 69%, respectively) of GLAST, a predominant glutamate transporter in cultured astroglia, though the mRNA levels appeared unaffected. Long-term treatment of cultures with dBcAMP stimulated D-[H-3]aspartate uptake as well as GLAST expression. Apart from glutamate, none of the agonists used was capable of increasing further the uptake capacity of the dBcAMP-treated astroglia. The glutamate receptor-dependent modulation of glutamate transport in astroglial cultures may represent a novel feedback regulatory mechanism for glutamate uptake in the brain.
|Titolo:||Glutamate receptor agonists up-regulate glutamate transporter GLAST in astrocytes|
|Parole Chiave:||Astrocytes; Cyclic AMP; Gene expression; Glutamate receptors; Glutamate/aspartate transporters; mRNA|
|Settore Scientifico Disciplinare:||Settore BIO/14 - Farmacologia|
|Data di pubblicazione:||1997|
|Digital Object Identifier (DOI):||10.1097/00001756-199612200-00052|
|Appare nelle tipologie:||01 - Articolo su periodico|