Role of nitric oxide in airway remodelling

Airway remodelling, which is manifested by thickening of bronchial wall, is an important causative factor of bronchial hyper-responsiveness in asthma. The pathophysiological mechanism of airway remodelling is not clear. In th e present study we evaluated the relationship between nitric oxide (NO) gen eration and airway wall thickening in patients with chronic asthma. As a ma rker of NO production, the levels of nitrite/nitrate were measured in induc ed sputum, and bronchial wall thickening was measured by high-resolution co mputed tomography. Sputum concentrations of nitrite/nitrate were significan tly increased in asthmatic patients compared with controls. The ratio of ai rway wall thickness to lumen diameter was significantly correlated with the sputum concentration of nitrite/nitrate. Although statistical correlation does not prove causation, this finding suggests that NO may play a key role in the pathogenesis of airway remodelling.