Basilar ArteryPituitary GlandPituitary NeoplasmsPituitary Gland, AnteriorArteriesVertebrobasilar InsufficiencyVertebral ArteryPituitary DiseasesCerebral ArteriesPituitary HormonesPulmonary ArteryPituitary ApoplexyCarotid ArteriesSubarachnoid HemorrhageBrain Stem InfarctionsCerebral AngiographyVasospasm, IntracranialMesenteric ArteriesPituitary Hormones, AnteriorRenal ArteryFemoral ArteryVasodilationPituitary Adenylate Cyclase-Activating PolypeptidePituitary Gland, PosteriorVasoconstrictionCarotid Artery, InternalIntracranial AneurysmAdenomaProlactinMuscle, Smooth, VascularIliac ArteryCoronary Artery BypassRadial ArteryDogsArterial Occlusive DiseasesMammary ArteriesVasodilator AgentsPituitary Function TestsProlactinomaMagnetic Resonance AngiographyCarotid Artery DiseasesSerotoninGonadotropins, PituitarySubclavian ArteryCerebrovascular CirculationTomography, X-Ray ComputedMiddle Cerebral ArteryGrowth Hormone-Secreting Pituitary AdenomaGrowth HormoneHypopituitarismAdrenocorticotropic HormonePituitary ACTH HypersecretionPotassium ChlorideACTH-Secreting Pituitary AdenomaSplenic ArteryBrachial ArteryLuteinizing HormonePapaverineCircle of WillisCoronary VesselsMuscle ContractionRabbitsGonadotropin-Releasing HormoneHepatic ArteryVasoconstrictor AgentsCarotid Artery, CommonPicolinesSumatriptanTreatment OutcomeTime FactorsAcetylcholineEndothelium, VascularAngiography, Digital SubtractionDose-Response Relationship, DrugUltrasonography, Doppler, TranscranialAneurysm, RupturedCeliac ArteryThyrotropin-Releasing HormoneIschemic Attack, TransientIntracranial ArteriosclerosisOphthalmic ArteryRats, Sprague-DawleyMesenteric Artery, SuperiorMagnetic Resonance ImagingEmbolization, TherapeuticIntracranial Embolism and ThrombosisPonsDwarfism, PituitaryPituitary Hormone-Releasing HormonesReceptors, Pituitary HormoneAngiographyUmbilical ArteriesRenal Artery ObstructionThoracic ArteriesVasomotor SystemCerebral InfarctionTemporal ArteriesFollicle Stimulating HormoneAdenoma, ChromophobeNitroprusside