Basilar ArteryArteriesVertebrobasilar InsufficiencyCerebral ArteriesPulmonary ArteryVertebral ArteryCarotid ArteriesRenal ArteryMesenteric ArteriesFemoral ArteryIliac ArteryCarotid Artery, InternalCoronary Artery BypassRadial ArteryMammary ArteriesSubarachnoid HemorrhageCerebral AngiographyBrain Stem InfarctionsVasodilationSubclavian ArteryCarotid Artery DiseasesVasoconstrictionVasospasm, IntracranialSplenic ArteryBrachial ArteryMuscle, Smooth, VascularHepatic ArteryCarotid Artery, CommonCoronary VesselsMiddle Cerebral ArteryArterial Occlusive DiseasesIntracranial AneurysmCeliac ArteryOphthalmic ArteryVasodilator AgentsMesenteric Artery, SuperiorMagnetic Resonance AngiographyUmbilical ArteriesRenal Artery ObstructionDogsThoracic ArteriesTomography, X-Ray ComputedTemporal ArteriesCerebrovascular CirculationBronchial ArteriesPopliteal ArteryEndothelium, VascularUlnar ArteryAngiographyVasoconstrictor AgentsSerotoninUterine ArteryTreatment OutcomeCoronary AngiographyCarotid Artery, ExternalCircle of WillisPotassium ChlorideMuscle ContractionAngiography, Digital SubtractionAcetylcholineRabbitsEmbolization, TherapeuticPapaverineCarotid Artery InjuriesStentsAneurysm, RupturedUltrasonography, Doppler, TranscranialIschemic Attack, TransientCoronary DiseaseRegional Blood FlowTime FactorsAneurysmCarotid StenosisIntracranial ArteriosclerosisSumatriptanInfarction, Middle Cerebral ArteryAxillary ArteryConstriction, PathologicPicolinesIntracranial Embolism and ThrombosisVasomotor SystemCerebral InfarctionRetinal Artery OcclusionNitroglycerinCarotid Artery ThrombosisMuscle RelaxationDose-Response Relationship, DrugNitroprussideBlood PressureMeningeal ArteriesAngioplasty, BalloonFollow-Up StudiesSubclavian Steal SyndromeVertebral Artery DissectionInjections, Intra-ArterialNitric OxideRats, Sprague-DawleyBrain IschemiaVascular PatencyNorepinephrine