EFFECT OF NITRIC OXIDE ON LUNG SURFACTANT SECRETION

Lung surfactant is secreted from epithelial type II cells into alveolar airspace in response to airborne and circulating stimuli. Nitric oxide (NO) can be generated by constitutive and inducible nitric oxide synthases (cNOS and iNOS) in pulmonary endothelial and epithelial cells. The authors therefore examined the effects of NO on lung surfactant secretion using an isolated perfused rat lung model and primary culture of type II cells. Infusion of L - N G -nitroarginine methyl ester (L -NAME) (100 μ M), an inhibitor of cNOS and iNOS, via pulmonary circulation for 90 minutes resulted in a decrease of lung surfactant secretion (1.55% ± 0.15% in control versus 0.79% ± 0.16% in L -NAME-treated lungs, P