Nitric oxide (NO) exerts cytotoxic effects on various cells including neuronal cells. Glial NO production, mediated via induction of inducible NO synthase (iNOS), enhances neurotoxicity associated with the N-methyl-D- aspartate (NMDA) receptor. The present study examined whether nicotinamide, an inhibitor of poly (ADP-ribose) synthetase, inhibits NO formation in primary culture of rat glial cells. Nicotinamide (5-20 mM) suppressed iNOS mRNA expression and subsequent NO formation, which were induced by the combination of interferon-γ and lipopolysaccharide, in a dose dependent manner. In addition, high-concentration (20 mM) nicotinamide decreased mRNA of interferon regulatory factor-1, a transcription factor which plays a major role in iNOS mRNA induction. These results suggest thai nicotinamide may have protective effect on glial NO-related pathologies by preventing iNOS mRNA induction.
- Glial cells
- Inducible nitric oxide synthase
- Nitric oxide
- Nitric oxide synthase
- Poly (ADP- ribose) synthetase
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