Nitric oxide inhibits surfactant protein B gene expression in lung epithelial cells.

Surfactant protein B (SP-B) is an essential constituent of pulmonary surfactant. In a number of inflammatory diseases of the lung, elevated nitric oxide (NO) levels are associated with decreased SP-B levels, suggesting that reduced SP-B levels contribute to lung injury. In this study, we investigated the effects of NO on SP-B gene expression in H441 and MLE-12 cells, cell lines with characteristics of bronchiolar (Clara) and alveolar type II epithelial cells, respectively.