Mesenteric Artery, InferiorColicMesenteric ArteriesMesenteric Artery, SuperiorRenal ColicArteriesChoroid PlexusBrachial PlexusPulmonary ArteryRenal ArteryCeliac ArteryCerebral ArteriesCarotid ArteriesFemoral ArteryMesenteric Vascular OcclusionBasilar ArteryVena Cava, InferiorSuperior Mesenteric Artery SyndromeMyenteric PlexusIliac ArteryVertebral ArteryCoronary Artery BypassVasodilationMuscle, Smooth, VascularVasoconstrictionSplenic ArteryRadial ArteryMammary ArteriesInferior ColliculiSubmucous PlexusHepatic ArteryCarotid Artery, InternalSubclavian ArteryFecal ImpactionSplanchnic CirculationCarotid Artery DiseasesMesenteric VeinsVasodilator AgentsHorse DiseasesTomography, X-Ray ComputedVena Cava, SuperiorVasoconstrictor AgentsBrachial ArterySuperior ColliculiEndothelium, VascularCoronary VesselsTreatment OutcomeChoroid Plexus NeoplasmsBiological FactorsCarotid Artery, CommonCervical PlexusLumbosacral PlexusCeliac PlexusTime FactorsAngiographyNorepinephrineOphthalmic ArteryRenal Artery ObstructionAcetylcholineUreteral DiseasesRats, WistarUmbilical ArteriesMiddle Cerebral ArteryThoracic ArteriesRats, Sprague-DawleyPhenylephrineBlood PressureMyographyTemporal ArteriesSimethiconeAneurysmBronchial ArteriesArterial Occlusive DiseasesPopliteal ArteryMuscle ContractionDose-Response Relationship, DrugRegional Blood FlowUlnar ArteryStentsNitric OxideCoronary AngiographyMuscle RelaxationMagnetic Resonance ImagingDogs