VasoconstrictionVasoconstrictor AgentsRegional Blood FlowVascular ResistancePulmonary CirculationAnoxiaArteriolesPulmonary ArteryBlood PressureVasodilationEndothelin-1NorepinephrineShiveringForearmSkin TemperatureRenal CirculationPhenylephrineMesenteric ArteriesVasomotor SystemBody Temperature RegulationHemodynamicsMuscle, Smooth, VascularReceptors, EndothelinAdrenergic alpha-1 Receptor AgonistsAdrenergic alpha-AgonistsVasodilator AgentsSympathetic Nervous SystemNitric OxideEndothelinsPerfusionReceptor, Endothelin AAdrenergic alpha-AntagonistsDogsArteriesAngiotensin IIDose-Response Relationship, DrugReceptor, Endothelin B15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidNG-Nitroarginine Methyl EsterReceptors, Adrenergic, alphaRats, Sprague-DawleyHeadache Disorders, PrimaryMethoxamineCoronary VesselsTyramineSplanchnic CirculationEndothelium, VascularViper VenomsHeart RatePrazosinMicrocirculation