NitroprussideVasodilator AgentsFerricyanidesVasodilationNitric OxideNitric Oxide DonorsAcetylcholineForearmEndothelium, VascularCyclic GMPRegional Blood FlowNG-Nitroarginine Methyl EsterVasoconstrictor AgentsVascular Resistanceomega-N-MethylarginineNitroglycerinBlood PressureNitric Oxide SynthaseVasoconstrictionBradykininArgininePhenylephrineHemodynamicsMuscle RelaxationHypotension, ControlledNitroarginineDose-Response Relationship, DrugGuanylate CyclaseEnzyme InhibitorsMesenteric ArteriesArteriolesMuscle, Smooth, VascularVasomotor SystemPlethysmographyHydralazineS-Nitroso-N-AcetylpenicillamineCoronary VesselsOxadiazolesDogsEpoprostenolPapaverineTrimethaphanPenicillamineNorepinephrineCromakalimAorta, ThoracicCoronary CirculationHyperemiaHeart RateMicrocirculationArteriesPulmonary CirculationAdenosineInfusions, Intra-Arterial15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidCalcitonin Gene-Related PeptideRats, WistarMolsidomineRats, Sprague-DawleyIndomethacinMethylene BlueBiological FactorsSplanchnic CirculationSodium NitriteEndothelium-Dependent Relaxing FactorsAortaPulmonary ArteryBenzopyransHypertensionHypertension, PulmonaryLaser-Doppler FlowmetryMuscle TonusBaroreflexIsosorbide DinitrateNitroso CompoundsMuscle ContractionSympathetic Nervous SystemRabbitsPurinonesBlood Flow VelocityNitric Oxide Synthase Type IIIIontophoresisVerapamilRenal CirculationAntihypertensive AgentsMinoxidilQuinoxalinesRats, Inbred WKYCyclooxygenase InhibitorsProstaglandinsMethoxaminePerfusionHypotensionIloprostCardiac OutputIsoproterenolBrachial ArteryPotassium ChlorideRats, Inbred SHRInjections, Intra-Arterial