Inhaled nitric oxide decreases pulmonary soluble guanylate cyclase protein levels in 1-month-old lambs
| Autor: | Stephen M. Black, Janine M. Bekker, Michael J. Johengen, Jeffrey R. Fineman, Stephan Thelitz, Regan B. Stuart, Boaz Ovadia |
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| Rok vydání: | 2004 |
| Předmět: |
Pulmonary and Respiratory Medicine
Pulmonary Circulation medicine.medical_specialty Vasodilator Agents Blotting Western Nitric Oxide Nitric oxide chemistry.chemical_compound 3' 5'-Cyclic-GMP Phosphodiesterases Internal medicine Administration Inhalation Animals Medicine Respiratory system Cyclic GMP Lung Cyclic guanosine monophosphate Cyclic Nucleotide Phosphodiesterases Type 5 Sheep Phosphoric Diester Hydrolases business.industry Hemodynamics medicine.disease Pulmonary hypertension Endocrinology medicine.anatomical_structure chemistry Guanylate Cyclase cGMP-specific phosphodiesterase type 5 Circulatory system Vascular resistance Vascular Resistance Surgery Cardiology and Cardiovascular Medicine business |
| Zdroj: | The Journal of Thoracic and Cardiovascular Surgery. 127:1285-1292 |
| ISSN: | 0022-5223 |
| DOI: | 10.1016/j.jtcvs.2003.07.024 |
| Popis: | BackgroundInhaled nitric oxide produces potent pulmonary vasodilation by activating soluble guanylate cyclase and increasing smooth muscle cell concentrations of cyclic guanosine monophosphate. However, responses are often nonsustained, and clinically significant increases in pulmonary vascular resistance have been noted on its acute withdrawal. In vitro and in vivo data suggest that inhaled nitric oxide decreases endogenous nitric oxide synthase activity. The effects of inhaled nitric oxide on the downstream mediators of the nitric oxide/cyclic guanosine monophosphate cascade, soluble guanylate cyclase and phosphodiesterase 5, have not been investigated. We sought to determine the effects of inhaled nitric oxide on endogenous cyclic guanosine monophosphate levels, soluble guanylate cyclase, and phosphodiesterase 5 protein levels in the intact lamb.MethodsEleven 1-month-old lambs were mechanically ventilated. In 7 lambs, inhaled nitric oxide (40 ppm) was administered for 24 hours and then acutely withdrawn. Intermittent lung biopsy samples were obtained for cyclic guanosine monophosphate concentrations and soluble guanylate cyclase and phosphodiesterase 5 protein levels (Western blot analysis).ResultsInitiation of nitric oxide decreased left pulmonary vascular resistance by 26.2%, and withdrawal rapidly increased pulmonary vascular resistance by 77.8% (P < .05). Tissue cyclic guanosine monophosphate concentrations initially increased during nitric oxide therapy but were not maintained during the 24-hour exposure. In addition, cyclic guanosine monophosphate concentrations rapidly decreased after nitric oxide withdrawal (P < .05). The α soluble guanylate cyclase (−45.7%) and β soluble guanylate cyclase (−48.4%) protein levels decreased during nitric oxide therapy (P < .05), whereas phosphodiesterase 5 proteins levels were unchanged.ConclusionsThese data suggest a role for decreased soluble guanylate cyclase and its resulting decrease in cyclic guanosine monophosphate concentrations in the nonsustained response to nitric oxide and the rebound pulmonary hypertension noted on its acute withdrawal. Phosphodiesterase 5 inhibitors may be a useful adjunct therapy during inhaled nitric oxide to preserve cyclic guanosine monophosphate levels and thereby preserve nitric oxide responsiveness and prevent rebound pulmonary hypertension. |
| Databáze: | OpenAIRE |
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