Hypoxia stimulates glutamate uptake in whole rat retinal cells in vitro.
Glutamate uptake in neurons and glial cells is essential to prevent the persistence of excitotoxic levels of glutamate observed during ischemia. We demonstrated that a short period of hypoxia stimulated the apparent glutamate transport rate in isolated rat retinal cells. The observed increase in glutamate uptake was not affected by glutamate receptor antagonists, protein kinase inhibitors, antioxidant or neo-synthesis inhibitors. However, inhibition of actin polymerization reversed the hypoxia-induced increase in glutamate uptake, suggesting a mobilization of transporters to the cell membrane. Moreover, the depletion in cell glutathione stimulated in the same manner the glutamate uptake and emphasized the key role of glutamate in the control of the level of this antioxidant. This rapid up-regulation of glutamate transport could be considered as an adaptative mechanism of neuroprotection.
Payet
Olivier
O
Laboratoire de Physiologie Cellulaire UMR-CNRS 5074, Montpellier, France.
Maurin
Laurence
L
Bonne
Claude
C
Muller
Agnès
A
D000199:Actins / Q000187:drug effects / Q000378:metabolism; D027322:Amino Acid Transport System X-AG / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002352:Carrier Proteins; D015687:Cell Hypoxia / Q000502:physiology*; D002478:Cells, Cultured; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors; D012160:Retina / Q000166:cytology / Q000378:metabolism*
D000199:Actins; D027322:Amino Acid Transport System X-AG; D000975:Antioxidants; D002352:Carrier Proteins; D018691:Excitatory Amino Acid Antagonists; D047908:Intracellular Signaling Peptides and Proteins; D017981:Receptors, Neurotransmitter; C069474:glutamine receptor; C015482:protein kinase modulator; D018698:Glutamic Acid