Related Experiment Videos
Endothelial nitric oxide synthase function in pig lung after chronic pulmonary artery obstruction
E Fadel1, G M Mazmanian, B Baudet
1Laboratoire de Chirurgie Expérimentale, Hôpital Marie, Lannelongue, Université Paris Sud, Le Plessis Robinson, France. eliefadel@lemel.fr
American Journal of Respiratory and Critical Care Medicine
|October 13, 2000
Summary
Long-term pulmonary artery obstruction in piglets preserved lung energy metabolism but reduced nitric oxide synthase function and protein in arteries. This suggests prolonged obstruction impairs vascular health despite metabolic adaptations.
Area of Science:
- Cardiovascular Physiology
- Pulmonary Hypertension Research
- Vascular Biology
Background:
- Pulmonary artery (PA) obstruction can lead to increased systemic blood supply, potentially preventing chronic ischemia and preserving endothelial nitric oxide synthase (eNOS) function.
- Understanding the long-term effects of PA obstruction on vascular function is crucial for managing related cardiopulmonary conditions.
Purpose of the Study:
- To investigate the impact of prolonged pulmonary artery occlusion on lung energy metabolism and eNOS function in a porcine model.
- To determine if preserved energy metabolism in post-obstructive pulmonary arteries correlates with maintained eNOS activity and vascular relaxation.
Main Methods:
- Piglets underwent left PA ligation or sham operation, with assessments at 2 days and 5 weeks.
- Measurements included lung ATP and lactate, nitric oxide synthase (NOS) activity (calcium-dependent and independent), eNOS protein levels, and PA relaxations to vasoactive agents.
Main Results:
- Five weeks of PA occlusion attenuated decreases in ATP and increases in lactate compared to sham or 2-day ligation.
- Calcium-dependent NOS activity and eNOS protein were significantly lower in piglets with long-term PA occlusion.
- Vascular relaxations to acetylcholine and calcium ionophore were impaired after 5 weeks of PA occlusion.
Conclusions:
- Despite relative conservation of lung energy metabolism, prolonged PA occlusion leads to decreased eNOS function and protein in post-obstructive pulmonary arteries.
- These findings indicate that long-term pulmonary artery obstruction adversely affects endothelial function in the pulmonary vasculature, even with compensatory metabolic adaptations.