Retinal toxicity of commercial tissue plasminogen activator is mediated by the induction of nitric oxide in the mouse retinal primary cells.
OBJECTIVE
Tissue plasminogen activator (tPA) is an efficient thrombolytic agent, but the dose-dependent retinal toxicity of intravitreal injection of commercial tPA (containing L-arginine) has been reported. Here, we sought to investigate the mechanism of tPA-induced cell death in mouse retinal cell cultures and the role of nitric oxide (NO).


METHODS
Primary retinal cell cultures were maintained using glial conditioned medium (GCM) solution. Mouse retinal cell death was observed by using Hoechst-propidium iodide staining. Mouse retinal cell death was also measured by lactate dehydrogenase (LDH) assay. The formation of NO was measured using Griess reagent.


RESULTS
tPA-induced cell death was detected in mouse retinal cell cultures by Hoechst-propidium iodide staining or LDH assay. L-arginine seems to be the major factor in retinal toxicity of commercial tPA (containing L-arginine). The formation of NO was markedly increased in mouse retinal cell cultures treated with tPA (containing L-arginine) or L-arginine. NO inhibitor reduced the cell death induced by commercially available tPA or L-arginine.


CONCLUSIONS
This study suggests that l-arginine from commercial tPA (containing L-arginine) induces the majority of cell death in mouse retinal cell cultures and that its cytotoxicity may depend on the induction of NO.
Oh
Hyun-Sub
HS
Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul 120-752, Korea.
Kwon
Oh W
OW
Chung
In
I
Lee
Sung C
SC
Koh
Hyoung J
HJ
Lee
Sung-Ho
SH
Lee
Joon H
JH
D000818:Animals; D001120:Arginine / Q000633:toxicity*; D006690:Bisbenzimidazole / Q000378:metabolism; D018929:Cell Culture Techniques; D016923:Cell Death / Q000187:drug effects; D003132:Commerce; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005343:Fibrinolytic Agents / Q000633:toxicity*; D005456:Fluorescent Dyes / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000633:toxicity*; D019323:omega-N-Methylarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D005343:Fibrinolytic Agents; D005456:Fluorescent Dyes; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D007770:L-Lactate Dehydrogenase; D019001:Nitric Oxide Synthase; D010959:Tissue Plasminogen Activator; D006690:Bisbenzimidazole