An Experimental Study of Atrial Natriuretic Peptide Levels and the Effect of Inhaled Nitric Oxide After Pneumonectomy

Abstract: The aim of this study was to investigate the changes in atrial natriuretic peptide (ANP) levels and lung cyclic guanosine 3′,5′-monophosphate (cGMP) concentrations caused by pneumonectomy (Pn), and the effect of inhaled nitric oxide (NO) after Pn in a canine model. The mean pulmonary arterial pressure (PAP) and plasma ANP levels were measured over 180 min in two groups of dogs, one subjected to 60 min of 5 ppm NO inhalation (Pn + NO group, n = 5) and one subjected to 180 min without NO inhalation (Pn group, n = 5). The ANP and cGMP levels in the lung were also measured before and after Pn. Both the PAP and ANP levels increased significantly. Inhaled NO rapidly reduced the PAP and plasma ANP to levels similar to those before Pn. The lung ANP level was significantly increased after Pn, but inhaled NO reduced it to a level similar to that before Pn. The lung cGMP level, which was significantly decreased after Pn, was significantly increased by NO inhalation. These results indicate that NO administration may be effective for preventing post-Pn pulmonary hypertension, although an elevation in ANP does not reduce the PAP.