MethylergonovineVasoconstrictionCerebral ArteriesMiddle Cerebral ArteryInfarction, Middle Cerebral ArteryArteriesCerebrovascular CirculationCerebral InfarctionPosterior Cerebral ArteryAnterior Cerebral ArteryBrain IschemiaPulmonary ArteryBasilar ArteryCerebral AngiographyMesenteric ArteriesCerebral Arterial DiseasesCarotid ArteriesVasoconstrictor AgentsBrainRegional Blood FlowRenal ArteryIschemic Attack, TransientFemoral ArteryVasodilationBlood PressureBlood Flow VelocityArterial Occlusive DiseasesCerebral PalsyMuscle, Smooth, VascularCarotid Artery, InternalUltrasonography, Doppler, TranscranialRats, Sprague-DawleyVertebral ArteryVascular ResistanceInfarction, Anterior Cerebral ArteryIntracranial AneurysmSubarachnoid HemorrhageVasodilator AgentsHemodynamicsIntracranial Embolism and ThrombosisVasomotor SystemAnoxiaCoronary VesselsTemporal ArteriesBrain EdemaTime FactorsCerebral HemorrhageArteriolesTomography, X-Ray ComputedCircle of WillisCerebral VeinsDogsCarotid Artery DiseasesInfarction, Posterior Cerebral ArteryNorepinephrineDisease Models, AnimalIliac ArteryMagnetic Resonance AngiographyRats, WistarEndothelium, VascularPulmonary CirculationCerebrovascular DisordersStrokeRadial ArteryCoronary Artery BypassNitric OxideReperfusionCerebral RevascularizationDose-Response Relationship, DrugMammary ArteriesVasospasm, IntracranialEndothelin-1Magnetic Resonance ImagingUmbilical ArteriesPhenylephrineMalaria, CerebralSplenic ArteryPia MaterNeuroprotective AgentsLaser-Doppler FlowmetryBrachial ArteryCarotid Artery, CommonSubclavian ArteryOxygenCarotid Artery, External