Dual action of nitric oxide on purely isolated retinal ganglion cells.
OBJECTIVE
The role of nitric oxide (NO) in the survival of retinal ganglion cells (RGCs) was investigated.


METHODS
RGCs were purely isolated from postnatal Sprague-Dawley rats by 2-step panning and were cultured in chemically defined serum free medium. An NO releaser, S-nitroso-N-acetylpenicillamine (SNAP: 500 microM, 250 microM, 100 microM, 10 microM, 1 microM, 100 nM, and 10 nM), an NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5 tetramethylimidazoline-1-oxyl-3-oxide potassium salt (c-PTIO: 100 microM, 33 microM, 10 microM, 1 microM), mixture of 100 microM SNAP and 33 microM c-PTIO, N(G)-nitro-L-arginine methyl ester (L-NAME: 10 mM, 5 mM, 500 microM, 100 microM or 10 microM), or their vehicles were added to the medium of pure RGC culture for 48 hr. Survival rates of small and large RGCs were determined separately by flow cytometry.


RESULTS
At > or = 100 microM, SNAP significantly reduced RGC survival in a concentration dependent manner. At < or = 41 microM, SNAP significantly increased survival, particularly of large RGCs. c-PTIO and L-NAME reduced the survival rates concentration-dependently. A mixture of 100 microM SNAP and 33 microM c-PTIO significantly improved RGC survival compared with when they were added on their own.


CONCLUSIONS
These results indicate that NO exhibits neuroprotective and neurotoxic actions on RGCs and that low concentrations of NO may be beneficial for the survival of neonatal RGCs in vitro.
Kashiwagi
K
K
Department of Ophthalmology, Yamanashi Medical University, Tamaho Yamanashi, Japan. kenjik@res.yamanashi-med.ac.jp
Iizuka
Y
Y
Tanaka
Y
Y
Mochizuki
S
S
Kajiya
F
F
Araie
M
M
Suzuki
Y
Y
Iijima
H
H
Tsukahara
S
S
D000818:Animals; D000831:Animals, Newborn; D002469:Cell Separation; D002470:Cell Survival / Q000502:physiology*; D002478:Cells, Cultured; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004338:Drug Combinations; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism
D003497:Cyclic N-Oxides; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D007093:Imidazoles; D020030:Nitric Oxide Donors; C110881:S-nitro-N-acetylpenicillamine; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; D009569:Nitric Oxide; D010396:Penicillamine; D019331:NG-Nitroarginine Methyl Ester