ColicMesenteric ArteriesMesenteric Artery, SuperiorRenal ColicMesenteric Artery, InferiorArteriesMesenteric Vascular OcclusionCeliac ArterySuperior Mesenteric Artery SyndromePulmonary ArteryRenal ArteryFecal ImpactionCerebral ArteriesCarotid ArteriesMuscle, Smooth, VascularVasodilationFemoral ArteryHorse DiseasesVasoconstrictionSplanchnic CirculationBasilar ArteryEmbolization, TherapeuticMesenteric VeinsBiological FactorsVasoconstrictor AgentsVasodilator AgentsSplenic ArteryUreteral DiseasesIliac ArteryEndothelium, VascularSimethiconeVertebral ArteryHepatic ArteryNorepinephrineCoronary Artery BypassTomography, X-Ray ComputedCarotid Artery, InternalPhenylephrineMyographyRadial ArteryMammary ArteriesRats, WistarTreatment OutcomeAngiographyAcetylcholineStomatognathic DiseasesEquidaeSubclavian ArteryCarotid Artery DiseasesDuodenostomyHorsesRats, Inbred WKYRats, Sprague-DawleyTime FactorsIntracranial AneurysmMuscle ContractionCoronary VesselsMuscle RelaxationAneurysmDose-Response Relationship, DrugNitric OxideBlood PressureCarotid Artery, CommonBrachial ArteryVena Cava, SuperiorSuperior ColliculiUrolithiasis