Nitric oxide synthase expression in lungs of pulmonary hypertensive patients with heart disease

Since little is known about the contribution of endothelial nitric oxide sy nthase (e-NOS) to the mechanism of pulmonary vasospasm and the development of pulmonary vascular occlusive disease, we elucidate how e-NOS is expresse d in lung biopsy specimens obtained from operative patients with pulmonary hypertension. Lung biopsy specimens were obtained from 17 patients who unde rwent open-heart operations for various heart diseases. A piece of normal l ung specimen was also obtained from the resected lungs of three lung cancer patients as a control. e-NOS expression was visualized with a monoclonal a ntibody against e-NOS, and the level of expression was partially quantified . Significantly high levels of e-NOS expression were seen in adult patients . whose preoperative mean pulmonary arterial pressures were greater than 20 mm HE. In contrast, e-NOS expression in pediatric patients with the same l evels of mean pulmonary arterial pressure was the same as that in the contr ols and in low pulmonary arterial pressure. There was a statistically signi ficant positive correlation between the level of eNOS expression and Heath- Edwards grading. These data suggest that the e-NOS expression in lung tissu e is induced when pulmonary vascular obstructive diseases progress. (C) 200 1 Elsevier Science Inc. All rights reserved.