Regional Blood FlowBlood Flow VelocityErgolinesHydrazinesDogsPentanoic AcidsReceptors, ThromboxaneTriazolamPlatelet AggregationXanthineReceptors, ProstaglandinCoronary ThrombosisCoronary CirculationThromboxane A2Genetic VariationYohimbineHemodynamicsCerebrovascular CirculationSerotonin AntagonistsEpinephrineCoronary DiseaseCoronary VesselsLaser-Doppler FlowmetryEndothelium, VascularFlow CytometryBlood PressureVascular ResistancePulsatile FlowXenon RadioisotopesMicrospheresMicrocirculationOxygenTime FactorsRenal CirculationOxygen ConsumptionVasodilationLiver CirculationBrainPulmonary CirculationTomography, Emission-ComputedRheologyCarbon DioxideGene FlowSplanchnic CirculationHeart RateHyperemiaOxygen RadioisotopesUltrasonography, DopplerXenonBlood VolumeBlood Circulation TimeUltrasonography, Doppler, ColorPlethysmographyVasodilator AgentsArteriesCerebral ArteriesCollateral CirculationModels, CardiovascularReproducibility of ResultsVasoconstrictionReference ValuesCapillariesUltrasonography, Doppler, TranscranialNitric OxidePartial PressureHindlimbIschemiaBlood Gas AnalysisLegAntigenic VariationMuscle, SkeletalAnalysis of VarianceSheepRetinal VesselsMiddle Cerebral ArterySwinePerfusionAntipyrineSkinRats, Sprague-DawleySkin TemperatureGenotypeMagnetic Resonance ImagingChoroidBrain IschemiaFemoral ArteryVasomotor SystemPolymorphism, Single NucleotideModels, BiologicalPregnancyAdenosineDNA Copy Number VariationsTomography, Emission-Computed, Single-PhotonNitrogen RadioisotopesHomeostasisOximesTechnetium Tc 99m ExametazimeKidneyArteriolesImage Processing, Computer-Assisted