Ryota Taguchi, H. Shirakawa, Toshiaki Yamaguchi
Mar 27, 2006
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0
Influential Citations
17
Citations
Quality indicators
Journal
European Journal of Pharmacology
Abstract
Abstract Nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy-3-nitroxy-2H-1-benzopyran) is used clinically as an anti-glaucoma ophthalmic solution in Japan, and was recently reported to suppress N-methyl- d -aspartate-induced retinal damage in rats. Here we investigated cytotoxic and cytoprotective actions of nipradilol on primary cultures of rat cortical neurons. Treatment of cortical cultures with a high concentration (500 μM) of nipradilol significantly reduced cell viability, increased lactate dehydrogenase (LDH) release and nitrite concentration in culture medium, whereas desnitro-nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy-3-hydroxy-2H-1-benzopyran) had no significant effects. Nipradilol-induced neuronal damage was inhibited by S-hexylglutathione, a glutathione S-transferase inhibitor, and FeTPPS (5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III) chloride), a peroxynitrite decomposition catalyst. On the other hand, relatively low concentrations (10–100 μM) of nipradilol but not desnitro-nipradilol prevented neuronal cell death induced by 24 h application of 100 μM glutamate. Importantly, neuroprotective concentration (100 μM) of nipradilol suppressed glutamate-induced elevation of intracellular Ca2+ concentrations, but had no effect on intracellular cyclic GMP levels. Hence, nipradilol can protect cultured cortical neurons against glutamate neurotoxicity via cyclic GMP-independent mechanisms, and nitric oxide (NO) released from the nitoroxy moiety of nipradilol may mediate neuroprotective effect through the modulation of NMDA receptor function.