Localization of nitric oxide synthedtase in nasal mucosa of mice with induced allergic rhinitit *
Nitric oxide（NO）is generated from L-arginine by nitric oxide synthase （NOS）, which is classified into neural NOS（NOS1）, inducible NOS（NOS2）and endothelial NOS（NOS3）. In patients with asthma, NO levels in exhaled air are high during immediate asthmatic responses. Several studies have reported expression of NOS2 within the epithelial cells of the trachea in asthmic patients and asthmic model animals. In patients with allergic rhinitis, NO levels in nasal air are high. NOS2 has been reported to increase in allergic rhinitis compared with controls. However, localization of NOS in the nasal mucosa of allergic rhinitis has not been examined. This reseach clarified the expression and localization of NOS（NOS1, NOS2, NOS3）in the nasal mucosa of allergic rhinitis using allergic model mice. Allergic rhinitis was induced in male mice at six weeks of age using purified Japanses ceder pollen allergen（Cry j 1）. Cry j 1 was injected three times into the abdomen（days0, 4, 8）and administered intranasally for 14 consecutive days（day 13-26）. Control mice were not done first and second immunology. On day 34, the expression and localization of NOS in the nasal mucosa of both the allergic model mice and the control mice were examined by immunohistochemistry and Real-time PCR. In the control mice, the expression of NOS2 was localized in the olfactory nerve, the nasal gland beneath the respiratory epithelium and vascular endothelial cells. In the allergic rhinitis group, the expression of NOS2 was not only localized in the olfactory nerve, nasal gland and vascular endothelial cells but also in the olfactory epithelium and respiratory epithelium. The real time-PCR showed that the expression of NOS2 and NOS3 in the allergic rhinitis significantly increased group compared with that in the control mice（p<0.05）. NOS2 localization was proven in the control group. In the allergic group, the expression of NOS2 increased especially in the olfactory epithelium and respiratory epithelium. The results of this study suggested that NOS2 and NOS3 have some relation to allergic rhinitis. (Accepted on November 13, 2008)
