Cerebrovascular CirculationRegional Blood FlowBlood Flow VelocityMicrospheresHemodynamicsVascular ResistanceDogsCardiac OutputBlood CirculationBlood PressureSplanchnic CirculationCoronary CirculationLaser-Doppler FlowmetryRenal CirculationScandiumLiver CirculationXenon RadioisotopesPulmonary CirculationHeart RateOxygenAnesthesiaOxygen ConsumptionTomography, Emission-ComputedBlood Gas AnalysisOxygen RadioisotopesNitrogen RadioisotopesMicrocirculationRadioisotopesFlow CytometryBrainCarbon DioxideNafronylVasodilationHindlimbPhentolamineKidneyBlood VolumeSwineVasoconstrictionVentilation-Perfusion RatioModels, CardiovascularPartial PressureVasodilator AgentsPulsatile FlowIschemiaOrganotechnetium CompoundsTime FactorsCollateral CirculationNG-Nitroarginine Methyl EsterRenal ArteryLegPulmonary Gas ExchangeNitric OxideHeartIliac ArteryImmersionSupine PositionAnesthesia, InhalationMyocardiumIsofluraneRats, Sprague-DawleyCatsTomography, Emission-Computed, Single-PhotonMuscle, SkeletalSheepInfusions, ParenteralSympathetic Nervous SystemPropranololArteriesMesenteric ArteriesNorepinephrineNitric Oxide SynthaseRats, WistarReference ValuesDose-Response Relationship, DrugRheologyMagnetic Resonance ImagingRabbitsDisease Models, AnimalRats, Inbred StrainsCapillariesInjections, IntravenousHyperemiaUltrasonography, DopplerForearmXenonGene FlowBlood Circulation TimeUltrasonography, Doppler, ColorCoronary VesselsLungPlethysmographyCerebral ArteriesMyocardial ContractionEnzyme InhibitorsAnoxiaUltrasonography, Doppler, TranscranialCoronary Disease