[Expression of inducible nitric oxide synthase in asthmatic rat lung].
OBJECTIVE
In order to study the role of nitric oxide (NO) during the airway inflammation of asthmatic rat, we investigated expression of inducible nitric oxide synthase (iNOS) in the lung tissue of asthmatic rats.


METHODS
Animal model of asthmatic Wistar rats was developed by being sensitized and challenged with ovalbumin. Activities of iNOS were measured by using SP immunohistochemical method.


RESULTS
In asthmatic rat group (n = 10), lung tissue showed stronger immunostaining (90%) for iNOS than control group (20%) (P < 0.001). Immunostaining was mainly present in the bronchial epithelium, alveolar epithelium, bronchial smooth muscle, vascular endothelial and smooth muscle cells and inflammatory cells such as macrophages and neutrophils. In glucocorticoid treated group (n = 10), there was down regulation of iNOS immunoreactivity (30% positive) compared with control asthmatic rat group (20%).


CONCLUSIONS
The increased expression of iNOS in asthmatic rat lung tissue showed NO playing a critical role in asthmatic inflammation, otherwise expression of iNOS was inhibited by glucocorticoid.
Huang
T
T
Department of Respiratory Diseases, PUMC Hospital, CAMS, PUMC, Beijing 100730, China.
Lin
Y
Y
Chen
Y
Y
Zhu
Y
Y
Luo
W
W
D000818:Animals; D001249:Asthma / Q000201:enzymology* / Q000503:physiopathology; D004195:Disease Models, Animal; D008168:Lung / Q000201:enzymology*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D009569:Nitric Oxide; D019001:Nitric Oxide Synthase