Basilar ArteryArteriesVertebrobasilar InsufficiencyVertebral ArteryCerebral ArteriesPulmonary ArteryCarotid ArteriesSubarachnoid HemorrhageBrain Stem InfarctionsCerebral AngiographyVasospasm, IntracranialMesenteric ArteriesRenal ArteryFemoral ArteryVasodilationVasoconstrictionCarotid Artery, InternalIntracranial AneurysmMuscle, Smooth, VascularIliac ArteryCoronary Artery BypassArterial Occlusive DiseasesMammary ArteriesRadial ArteryDogsMagnetic Resonance AngiographyVasodilator AgentsSubclavian ArteryCarotid Artery DiseasesSerotoninCerebrovascular CirculationMiddle Cerebral ArteryTomography, X-Ray ComputedCoronary VesselsSplenic ArteryCircle of WillisBrachial ArteryPotassium ChlorideHepatic ArteryPapaverineMuscle ContractionCarotid Artery, CommonVasoconstrictor AgentsRabbitsPicolinesAngiography, Digital SubtractionTreatment OutcomeSumatriptanAcetylcholineEndothelium, VascularEmbolization, TherapeuticAneurysm, RupturedUltrasonography, Doppler, TranscranialAngiographyMesenteric Artery, SuperiorIntracranial ArteriosclerosisOphthalmic ArteryCeliac ArteryIschemic Attack, TransientIntracranial Embolism and ThrombosisTime FactorsPonsThoracic ArteriesRenal Artery ObstructionUmbilical ArteriesVasomotor SystemTemporal ArteriesCerebral InfarctionBronchial ArteriesStentsPosterior Cerebral ArteryDose-Response Relationship, DrugUlnar ArteryNitroprussideCoronary AngiographyPopliteal ArteryMuscle RelaxationSubclavian Steal SyndromeNitroglycerinConstriction, PathologicBrain StemRegional Blood FlowCarotid Artery, ExternalInfusions, Intra-ArterialThrombolytic TherapyRats, Sprague-DawleyUterine ArterySpasmInjections, Intra-ArterialIntracranial ThrombosisAneurysmComaDilatation, Pathologic15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidRetinal Artery OcclusionNimodipineCarotid StenosisBrain IschemiaRats, Inbred WKYAneurysm, Dissecting