Basilar ArteryPonsArteriesVertebrobasilar InsufficiencyVertebral ArteryCerebral ArteriesBrain Stem InfarctionsPulmonary ArteryCarotid ArteriesSubarachnoid HemorrhageCerebral AngiographyVasospasm, IntracranialMesenteric ArteriesRenal ArteryFemoral ArteryVasodilationVasoconstrictionCarotid Artery, InternalBrain StemIntracranial AneurysmMuscle, Smooth, VascularIliac ArteryCoronary Artery BypassCerebrovascular CirculationRadial ArteryArterial Occlusive DiseasesMammary ArteriesVasodilator AgentsMagnetic Resonance AngiographyDogsCarotid Artery DiseasesSerotoninSubclavian ArteryTomography, X-Ray ComputedMiddle Cerebral ArterySplenic ArteryBrachial ArteryPotassium ChloridePapaverineCircle of WillisCoronary VesselsMuscle ContractionHepatic ArteryVasoconstrictor AgentsCarotid Artery, CommonPicolinesMagnetic Resonance ImagingSumatriptanRabbitsCerebral InfarctionAcetylcholineEndothelium, VascularBrainAngiography, Digital SubtractionUltrasonography, Doppler, TranscranialCeliac ArteryTreatment OutcomeIschemic Attack, TransientIntracranial ArteriosclerosisAneurysm, RupturedOphthalmic ArteryMesenteric Artery, SuperiorEmbolization, TherapeuticIntracranial Embolism and ThrombosisAngiographyUmbilical ArteriesRenal Artery ObstructionThoracic ArteriesVasomotor SystemTemporal ArteriesBronchial ArteriesRats, Sprague-DawleyNitroprussidePosterior Cerebral ArteryPopliteal ArteryMuscle RelaxationTime FactorsUlnar ArteryNitroglycerinSubclavian Steal SyndromeRegional Blood FlowDose-Response Relationship, DrugCerebellumStentsInfusions, Intra-ArterialUterine ArteryThrombolytic TherapySpasmConstriction, PathologicNorepinephrineIntracranial ThrombosisCerebrovascular DisordersBrain IschemiaCoronary AngiographyInjections, Intra-ArterialComaCarotid Artery, External15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidNimodipineCarotid Stenosis