Pyrrolizidine AlkaloidsPulmonary CirculationPulmonary ArteryLungBlood VesselsPulmonary Gas ExchangeGravitationVentilation-Perfusion RatioHypertension, PulmonarySheepHeart Bypass, RightPulmonary AtresiaHeart Defects, CongenitalVascular ResistanceLymphatic VesselsTechnetium Tc 99m Aggregated AlbuminRegional Blood FlowRetinal VesselsMicrospheresFractalsNoble GasesHemodynamicsPulmonary VeinsAnoxiaBlood Flow VelocityProne PositionHeart Septal Defects, VentricularHLA-DR6 AntigenOxygenatorsEndothelium, VascularFontan ProcedureNeovascularization, PhysiologicOxygenBlood Gas AnalysisExtravascular Lung WaterDogsBlood PressureNeovascularization, PathologicVasoconstrictionKrypton RadioisotopesHypoplastic Left Heart SyndromeCardiac OutputPulmonary EdemaCapillariesCoronary VesselsNitric OxideCapillary ResistancePulmonary Diffusing CapacityPartial PressureBronchial ArteriesFetusArteriovenous Shunt, SurgicalSupine PositionAortic Arch SyndromesPulmonary Valve StenosisGravity SuitsEndothelial CellsRespirationLung Volume MeasurementsDisease Models, AnimalMuscle, Smooth, VascularModels, CardiovascularImmunohistochemistryCarbon DioxideRespiration, ArtificialBlood VolumeNitric Oxide SynthaseEndothelin-1Vena Cava, SuperiorAortaVascular Endothelial Growth Factor ACardiac CatheterizationSheep, DomesticNitric Oxide Synthase Type IIIBronchopulmonary SequestrationVasodilationPulmonary Wedge PressurePulmonary VentilationPulmonary AlveoliAnimals, NewbornLiquid VentilationSwineCyanosisDuctus ArteriosusTurtlesArteriesMonocrotalineLung InjuryPericytesHead-Down TiltTime FactorsDuctus Arteriosus, PatentHydrogen SulfidePulmonary ValveRespiratory Dead SpaceInfant, NewbornCollateral CirculationAdministration, InhalationVasodilator AgentsAntigens, CD31