Vasodilator AgentsPulmonary CirculationHypertension, PulmonaryAdministration, InhalationVasodilationIloprostPulmonary ArteryVascular ResistanceSulfonesNitric OxidePurinesEpoprostenol15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidCyclic Nucleotide Phosphodiesterases, Type 5Pulmonary Wedge PressureHemodynamicsNitroprussideAlprostadilPhosphodiesterase InhibitorsPiperazines3',5'-Cyclic-GMP PhosphodiesterasesBlood PressureNitroglycerinLungSheepAnoxiaCyclic GMPNG-Nitroarginine Methyl EsterPulmonary Gas ExchangeCardiac OutputVasoconstrictionDogsAntihypertensive AgentsCardiac CatheterizationOxygenDose-Response Relationship, DrugAcetylcholineTreatment OutcomeRegional Blood FlowForearmEndothelium, VascularHydralazineBradykininPapaverineCalcitonin Gene-Related PeptideVasoconstrictor AgentsMesenteric ArteriesHyperemiaCoronary CirculationAdenosineCoronary VesselsVasomotor SystemSplanchnic Circulationomega-N-MethylarginineNitric Oxide SynthaseArginineArteriolesEndothelium-Dependent Relaxing FactorsPlethysmographyMuscle, Smooth, VascularAdrenomedullinRenal CirculationCromakalimIndomethacinNitroarginineDipyridamoleMinoxidilIsosorbide DinitrateArteriesBiological FactorsMicrocirculationEnzyme InhibitorsProstaglandinsHeart RateBenzopyransMuscle RelaxationNorepinephrineBlood Flow VelocityRats, WistarPhenylephrineMuscle TonusInfusions, Intra-ArterialRats, Sprague-DawleyNitric Oxide DonorsAorta, ThoracicSodium NitritePerfusionCyclooxygenase InhibitorsLaser-Doppler FlowmetryHypertensionBrachial ArteryNitric Oxide Synthase Type IIIHindlimb8,11,14-Eicosatrienoic AcidMethoxamineFerricyanidesSubstance PTolazolineReceptors, Calcitonin Gene-Related PeptideEndothelins