Effect of nitric oxide and peroxynitrite on mucociliary transport function of experimental otitis media.
OBJECTIVE
To determine the role of nitric oxide (NO) and peroxynitrite on mucociliary activity in experimental otitis media with effusion (OME).


METHODS
Twenty guinea pigs were divided into 1 control and 3 experimental groups; lipopolysaccharide (LPS), N(G)-nitro-L-arginine methyl ester (L-NAME), and uric acid (UA) groups. Ten ears were used in each group. OME was induced by transtympanic injection of LPS in experimental groups. Twenty-four hours after the transtympanic injection, dye transfer time (DTT) was measured and the temporal bone was taken for histopathologic examination. Expression of peroxynitrite was determined by immunohistochemical stain for 3-nitrotyrosine (3-NT).


RESULTS
Dye transfer time was significantly delayed in LPS group compared to control group; by contrast it was significantly reduced in L-NAME or UA treated groups (P < 0.01). Histopathologic examination showed reduced inflammation and mucosal thickening in the treatment groups when compared to LPS group. These findings, however, were not statistically significant. Immunoreactivity to 3-NT was intense in LPS group and decreased in the treatment groups (P < 0.05).


CONCLUSIONS
It is suggested that LPS induced mucociliary dysfunction in the middle ear by NO and peroxynitrite-mediated pathways.
Jeon
Eun-ju
EJ
Department of Otolaryngology-HNS, College of Medicine, The Catholic University of Korea, Our Lady of Mercy Hospital, 665 Bupyung-dong, Bupyung-gu, Incheon 403-720, Korea.
Park
Yong-Soo
YS
Lee
Seung Kyun
SK
Yeo
Sang-Won
SW
Park
Shi Nae
SN
Chang
Ki-Hong
KH
D000818:Animals; D004195:Disease Models, Animal; D016166:Free Radical Scavengers / Q000494:pharmacology; D006168:Guinea Pigs; D008070:Lipopolysaccharides / Q000494:pharmacology; D009079:Mucociliary Clearance / Q000187:drug effects / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010034:Otitis Media with Effusion / Q000503:physiopathology*; D030421:Peroxynitrous Acid / Q000502:physiology*; D011550:Pseudomonas aeruginosa; D014527:Uric Acid / Q000494:pharmacology
D016166:Free Radical Scavengers; D008070:Lipopolysaccharides; D030421:Peroxynitrous Acid; D014527:Uric Acid; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester