Regional Blood FlowMicrospheresBlood Flow VelocityCardiac OutputHemodynamicsCerebrovascular CirculationBlood CirculationDogsVascular ResistanceCoronary CirculationSplanchnic CirculationBlood PressureScandiumRenal CirculationLiver CirculationHeart RatePulmonary CirculationLaser-Doppler FlowmetryXenon RadioisotopesHeartAnesthesiaOxygenMyocytes, CardiacOxygen ConsumptionBlood Gas AnalysisRadioisotopesNafronylNitrogen RadioisotopesTomography, Emission-ComputedMyocardiumPhentolamineVentilation-Perfusion RatioOxygen RadioisotopesKidneyModels, CardiovascularSwineTime FactorsBrainCarbon DioxideHindlimbMicrocirculationOrganotechnetium CompoundsBlood VolumePartial PressureVasoconstrictionImmersionVasodilator AgentsIschemiaIliac ArteryPulmonary Gas ExchangeRenal ArteryVasodilationMyocardial ContractionSupine PositionRats, Sprague-DawleyAnesthesia, InhalationNG-Nitroarginine Methyl EsterCollateral CirculationIsofluraneNitric OxideInfusions, ParenteralLegCardiac Surgical ProceduresCatsTomography, Emission-Computed, Single-PhotonArrhythmias, CardiacPropranololMuscle, SkeletalRats, WistarMesenteric ArteriesNorepinephrineFlow CytometryDisease Models, AnimalSheepRabbitsCoronary VesselsForearmDeath, Sudden, CardiacDose-Response Relationship, DrugMyocardial InfarctionSympathetic Nervous SystemRats, Inbred StrainsMagnetic Resonance ImagingNitric Oxide SynthaseInjections, IntravenousPulsatile FlowReference ValuesArteriesLungCoronary DiseaseCardiac Pacing, ArtificialCapillariesCardiomegalyEnzyme InhibitorsCardiac TamponadeHeart DiseasesCardiac CatheterizationBlood DonorsHeart ArrestAnoxia