Basilar ArteryThrombosisVenous ThrombosisArteriesVertebrobasilar InsufficiencyVertebral ArteryCerebral ArteriesCoronary ThrombosisIntracranial ThrombosisSinus Thrombosis, IntracranialPulmonary ArteryCarotid ArteriesCarotid Artery ThrombosisSubarachnoid HemorrhageBrain Stem InfarctionsCerebral AngiographyFemoral ArteryVasospasm, IntracranialMesenteric ArteriesRenal ArteryIntracranial Embolism and ThrombosisVasodilationCarotid Artery, InternalVasoconstrictionIntracranial AneurysmIliac ArteryArterial Occlusive DiseasesMuscle, Smooth, VascularCoronary Artery BypassTomography, X-Ray ComputedMagnetic Resonance AngiographyAnticoagulantsTreatment OutcomeDogsRadial ArteryCarotid Artery DiseasesVasodilator AgentsMammary ArteriesStentsFibrinolytic AgentsCerebrovascular CirculationSubclavian ArteryHepatic ArterySerotoninCoronary VesselsTime FactorsMiddle Cerebral ArterySplenic ArterySagittal Sinus ThrombosisPhlebographyEndothelium, VascularThrombolytic TherapyRabbitsBrachial ArteryAngiographyCircle of WillisAngiography, Digital SubtractionCarotid Artery, CommonPotassium ChloridePapaverineVasoconstrictor AgentsMuscle ContractionPicolinesFollow-Up StudiesEmbolization, TherapeuticCeliac ArteryPlatelet Aggregation InhibitorsAneurysm, RupturedSumatriptanRisk FactorsFemoral VeinUltrasonography, Doppler, TranscranialIliac VeinIschemic Attack, TransientAcetylcholineIntracranial ArteriosclerosisRetrospective StudiesMesenteric Artery, SuperiorHeparinConstriction, PathologicCerebral InfarctionThrombophiliaCoronary AngiographyThrombectomyOphthalmic ArteryPortal VeinUpper Extremity Deep Vein ThrombosisRenal Artery ObstructionDose-Response Relationship, DrugProspective StudiesUmbilical ArteriesPopliteal ArteryDisease Models, AnimalAneurysmPonsVascular PatencyUlnar ArteryCerebral VeinsThoracic ArteriesVasomotor System