TY - JOUR T1 - Lung cGMP release subsequent to NO inhalation in pulmonary hypertension: responders <em>versus</em> nonresponders JF - European Respiratory Journal JO - Eur Respir J SP - 664 LP - 671 DO - 10.1183/09031936.02.00982001 VL - 19 IS - 4 AU - H.A. Ghofrani AU - R. Wiedemann AU - F. Rose AU - N. Weissmann AU - R.T. Schermuly AU - K. Quanz AU - F. Grimminger AU - W. Seeger AU - H. Olschewski Y1 - 2002/04/01 UR - http://erj.ersjournals.com/content/19/4/664.abstract N2 - Inhalation of nitric oxide (NO) is widely employed for the assessment of pulmonary vasoresponsiveness in pulmonary hypertension (PH). However, the reasons for the huge differences in vascular reactivity to NO between patients are unknown, and the role of NO-induced cyclic guanosine monophosphate (cGMP) is unclear. Twenty patients with severe precapillary PH were investigated. Thirty-six Swan-Ganz catheter investigations were performed and the study subjects were tested for responses to NO inhalation. This included an assessment of pulmonary and systemic arterial plasma cGMP and atrial natriuretic peptide (ANP) levels. A significant NO response (pulmonary vascular resistance (PVR) decrease &gt;20%) was noted in nine of 20 patients (45%) during the first catheterization. A highly significant correlation between baseline plasma cGMP and ANP levels with PVR was observed (r=0.62 and r=0.66, respectively; p&lt;0.0001). In response to NO, systemic and mixed venous cGMP levels increased from 13.9±1.28 nM and 12.75±0.99 nM to 79.23±4.99 nM and 55.25±4.41 nM (p&lt;0.001), respectively, accompanied by the appearance of a marked transpulmonary cGMP gradient. Although in the responder group ANP levels were significantly reduced after NO inhalation, no significant correlation was observed to the extent of PVR reduction. The magnitude of the NO-elicited cGMP response did not discriminate between haemodynamic responders and nonresponders. This study concludes that plasma cyclic guanosine monophosphate levels are significantly correlated with the severity of disease in pulmonary arterial hypertension. Nitric oxide inhalation provokes a prompt increase in cyclic guanosine monophosphate secretion, but the magnitude of this release is not linked with a decrease in pulmonary vascular resistance. This work was supported by a grant from the German Research Foundation. ER -