[The effects of hypoxia on the expression of inducible isoform of nitric oxide syntheses in nasal mucosal epithelial cells].
OBJECTIVE
To study the synthesis of inducible isoform of nitric oxide synthase (iNOS) in human nasal mucosal epithelial cells (HNMECs) under hypoxia, and the role of dexamethasone on this process.


METHODS
HNMECs were cultured without serum under normal condition and hypoxia for 3-48 hours, parts of them were cultured with dexamethasone. Cell cycle of epithelial cells was observed by flowcytometer. INOS mRNA was detected by in situ hybridization.


RESULTS
Cell cycle of epithelial cells became long under hypoxia. iNOS mRNA expression increased with time dependence after hypoxia for 3 h compared with controls. The peak appeared after 12 h hypoxia (P < 0.01). Increased iNOS mRNA expressions were reduced significantly by dexamethasone, but higher doses of dexamethasone (> 4.0 g/L) did not result in further suppression.


CONCLUSIONS
Hypoxia can regulate expression of iNOS mRNA significantly in HNMECs, and dexamethasone can restrain this process significantly.
Jiang
Shu
S
Department of Otorhinolaryngology-Head and Neck Surgery, China-Japan Union Hospital of Jilin University, Changchun 130031.
Dong
Zhen
Z
Zhu
Dongdong
D
Yang
Zhanquan
Z
Zhou
Weiguo
W
Zhao
Libo
L
D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D004847:Epithelial Cells / Q000201:enzymology; D006801:Humans; D000860:Hypoxia / Q000201:enzymology*; D009297:Nasal Mucosa / Q000201:enzymology*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects
D000893:Anti-Inflammatory Agents; D012333:RNA, Messenger; D003907:Dexamethasone; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II