Vasoconstrictor AgentsNorbornanesVasoconstrictionPhenylephrineAngiotensin IINorepinephrineVascular ResistanceSodiumMuscle, Smooth, VascularBlood PressureSodium ChannelsEndothelinsEndothelin-1Regional Blood FlowSodium, DietaryMesenteric ArteriesSympathetic Nervous SystemVasodilationVasomotor SystemSodium ChlorideReceptors, Endothelin15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidVasodilator AgentsRenal CirculationNitroprussideForearmNitric OxideMethoxamineDose-Response Relationship, DrugReceptor, Endothelin ATyramineRats, Sprague-DawleyArteriolesHemodynamicsArteriesReceptor, Endothelin BThromboxane A2Potassium ChlorideDogsEndothelium, VascularNG-Nitroarginine Methyl EsterKidneySodium Channel BlockersSodium IsotopesPerfusionProstaglandin Endoperoxides, SyntheticUrotensinsIndomethacinSodium Dodecyl SulfateRats, WistarAcetylcholineAdrenergic alpha-AgonistsSodium BicarbonateSerotoninNitric Oxide SynthaseReceptors, ThromboxaneSplanchnic CirculationMuscle TonusProstaglandinsArginine VasopressinEnzyme InhibitorsHydroxyeicosatetraenoic AcidsPeptides, CyclicNordefrinHeart RateRenal ArteryHypertensionViper VenomsAdrenergic alpha-AntagonistsSumatriptanPulmonary CirculationEpithelial Sodium ChannelsLaser-Doppler FlowmetrySodium NitriteAdrenergic alpha-1 Receptor AgonistsAdrenergic FibersRabbitsSodium CompoundsBlood VesselsVasopressinsPhentolamineSkin TemperaturePotassiumArginineomega-N-MethylarginineNitroarginineSodium SalicylateSodium Chloride, DietaryAstringentsBretylium CompoundsCromolyn SodiumSkinCyclooxygenase InhibitorsRats, Inbred StrainsElectric StimulationTailPlethysmographyTime FactorsAorta, ThoracicHindlimb