[Effect of N-methyl-D-aspartate and dexamethasone on apoptosis of rat cultured retinal ganglion cells].
OBJECTIVE
To investigate the effect of N-methyl-D-aspartate(NMDA) and Dexamethasone on cultured rat retinal ganglion cells (RGCS).


METHODS
RGCs were obtained from 1-3 days old SD rats. In two groups, exposure of cocultured ganglion cells to N-methyl-D-aspartate (20-500 mumol/L) lasted for 24 hours. Apoptotic cells were identified by Hochest 33258 in one group; In another group, 0.4% Trypan blue dye was added. Cells excluding the dye were counted, and the survival rate of cells was determined by the ratio of the excluding cells in the experiment over in the control; Cocultured RGCs and purified RGCs were exposed to Dexamethasone(1 x 10(-4), 1 x 10(-5) and 1 x 10(-6) mol/L). After 24 hours, apoptotic cells were identified by Hochest33258.


RESULTS
Cocultured RGCs showed distinct morphological appearance of apoptotic cells when they were exposed to NMDA. The survival rate of cells was dose-related to the concentration of NMDA. Cocultured RGCs didn't show typical apoptotic appearance at 24 hours after exposure to Dexamethasone. But purified RGCs did so, even in the control group.


CONCLUSIONS
NMDA has the effect of inducing cocultured RGCs apoptosis. Dexamethasone had no this effect on RGCs. Without additional neurotrophic factors, purified RGCs may become apoptotic cells when cultured in vitro for 24 hours.
Ge
J
J
Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China.
Wu
Y
Y
Qiu
P
P
Liu
H
H
Lin
M
M
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects*; D002470:Cell Survival; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D016202:N-Methylaspartate / Q000494:pharmacology*; D018696:Neuroprotective Agents / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000166:cytology*
D018696:Neuroprotective Agents; D016202:N-Methylaspartate; D003907:Dexamethasone