Protective action of zinc against glutamate neurotoxicity in cultured retinal neurons.
OBJECTIVE
To examine the effects of Zn2+ on glutamate-induced neurotoxicity in cultured retinal neurons.


METHODS
Primary cultures obtained from fetal rat retinas (16 to 19 days gestation) were used. The neurotoxic effects of excitatory amino acids were quantitatively assessed using the trypan blue exclusion method.


RESULTS
A brief exposure of retinal cultures to glutamate or N-methyl-D-aspartate (NMDA) induced delayed cell death. Zn2+ at concentrations of 3 to 30 microM ameliorated glutamate- and NMDA-induced neurotoxicity in a dose-dependent manner. By contrast, neurotoxicity induced by a 1-hour exposure to kainate was not affected by Zn2+.


CONCLUSIONS
These findings demonstrate that Zn2+ protects retinal neurons from NMDA receptor-mediated glutamate neurotoxicity.
Kikuchi
M
M
Department of Ophthalmology, Faculty of Medicine, Kyoto University, Japan.
Kashii
S
S
Honda
Y
Y
Ujihara
H
H
Sasa
M
M
Tamura
Y
Y
Akaike
A
A
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005333:Fetus; D018698:Glutamic Acid / Q000633:toxicity*; D007608:Kainic Acid / Q000633:toxicity; D016202:N-Methylaspartate / Q000633:toxicity; D009474:Neurons / Q000187:drug effects*; D051381:Rats; D017470:Receptors, Glutamate / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000187:drug effects*; D017967:Zinc Compounds / Q000494:pharmacology*
D002712:Chlorides; D017470:Receptors, Glutamate; D017967:Zinc Compounds; D018698:Glutamic Acid; D016202:N-Methylaspartate; C016837:zinc chloride; D007608:Kainic Acid