Ventilation-induced pulmonary vasodilatation in lambs with congenital diaphragmatic hernia is modulated by nitric oxide.
Endogenous nitric oxide (NO) mediates pulmonary vasodilatation at birth, but inhaled NO fails to reduce pulmonary vascular resistance (PVR) in newborns with congenital diaphragmatic hernia (CDH). This study was designed to investigate the effects of ventilation, and the nature of its endogenous mediator, in fetal lambs with experimental CDH. Investigations at 138 days of gestation showed that ventilation markedly decreased PVR. Inhibition of NO synthesis reduced ventilation-induced pulmonary vasodilatation in vivo and increased in vitro isometric tension of vascular rings. Ventilation therefore reduces PVR at birth in lambs with CDH, and endogenous NO seems to contribute to this reduction.
de Buys Roessingh
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AS
Université Paris Descartes, Faculté de Médecine, Assistance Publique-Hôpitaux de Paris, Service de Physiologie-Explorations Fonctionnelles, Hôpital Cochin, Paris, France. anthony.debuys-roessingh@CHUV.ch
de Lagausie
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Mercier
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JC
Aigrain
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Y
Dinh-Xuan
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AT
D000818:Animals; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005865:Gestational Age; D006439:Hemodynamics; D006548:Hernia, Diaphragmatic / Q000503:physiopathology / Q000628:therapy*; D065630:Hernias, Diaphragmatic, Congenital; D008168:Lung / Q000098:blood supply*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D019335:Nitroarginine / Q000494:pharmacology; D011652:Pulmonary Circulation / Q000187:drug effects; D012121:Respiration, Artificial; D012756:Sheep; D014655:Vascular Resistance; D014664:Vasodilation / Q000187:drug effects
D004791:Enzyme Inhibitors; D019335:Nitroarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase