Regional Blood FlowMicrospheresBlood Flow VelocityCardiac OutputCerebrovascular CirculationHemodynamicsBlood CirculationVascular ResistanceDogsCoronary CirculationSplanchnic CirculationBlood PressureScandiumRenal CirculationLiver CirculationPulmonary CirculationLaser-Doppler FlowmetryXenon RadioisotopesHeart RateOxygenAnesthesiaBlood Gas AnalysisRadioisotopesOxygen ConsumptionTomography, Emission-ComputedNitrogen RadioisotopesNafronylOxygen RadioisotopesBrainPhentolamineVentilation-Perfusion RatioKidneySwineCarbon DioxideTime FactorsHindlimbMicrocirculationOrganotechnetium CompoundsPartial PressureModels, CardiovascularBlood VolumeImmersionVasoconstrictionIliac ArteryIschemiaPulmonary Gas ExchangeRenal ArteryVasodilationVasodilator AgentsSupine PositionAnesthesia, InhalationHeartNG-Nitroarginine Methyl EsterMyocardiumCollateral CirculationLegIsofluraneInfusions, ParenteralNitric OxideFlow CytometryRats, Sprague-DawleyCatsMesenteric ArteriesMuscle, SkeletalReference ValuesTomography, Emission-Computed, Single-PhotonForearmSheepPropranololSympathetic Nervous SystemMagnetic Resonance ImagingNorepinephrineRabbitsRats, WistarPulsatile FlowDose-Response Relationship, DrugRats, Inbred StrainsReproducibility of ResultsInjections, IntravenousCoronary VesselsDisease Models, AnimalNitric Oxide SynthaseLungArteriesMyocardial ContractionCapillariesBlood DonorsRheologyMyocardial InfarctionEnzyme InhibitorsCoronary DiseaseUltrasonography, DopplerHyperemiaPostureXenonPlethysmographyUltrasonography, Doppler, ColorAnoxiaSensitivity and SpecificityContrast Media