Muscle RelaxationVasodilationVasodilator AgentsAcetylcholineAorta, ThoracicEndothelium, VascularNitric OxideNitroprussideAortaMuscle, Smooth, VascularCyclic GMPMesenteric ArteriesPhenylephrineVasoconstrictor AgentsNitric Oxide Synthase Type IIING-Nitroarginine Methyl EsterNitroglycerinDose-Response Relationship, DrugRats, Sprague-DawleyVasoconstrictionSodium Chloride, DietaryHeterocyclic Compounds, 3-RingBradykininNitric Oxide SynthaseGuanylate CyclaseNitric Oxide DonorsBlood PressureMuscle ContractionRelaxationRelaxation TherapyNitratesHypertensionIndomethacinRats, Inbred DahlArginineVasomotor SystemRabbitsPotassium ChlorideIsometric ContractionEnzyme InhibitorsSuperoxidesMiddle Cerebral ArteryRats, WistarRats, Inbred SHRBlood VesselsVascular ResistanceEndotheliumAngiotensin IIArteriesSodium, DietaryNitritesRats, Inbred WKYCalciumCoronary VesselsDiabetes Mellitus, ExperimentalNitroarginineBiological FactorsMuscle, SmoothSuperoxide DismutaseCattleDisease Models, AnimalMagnetic Resonance SpectroscopyMice, KnockoutSignal TransductionGastric FundusCells, CulturedMyocardial ContractionMice, Inbred C57BLMethylene BlueCharybdotoxinPenisOxadiazolesDiastoleElectric StimulationApamin15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidTracheaEsophageal Sphincter, LowerMuscle TonusGuinea PigsDogsIsoproterenolVasoactive Intestinal PeptideEsophagogastric JunctionSwineQuinoxalinesNuclear Magnetic Resonance, BiomolecularEndothelium-Dependent Relaxing FactorsCromakalimNorepinephrineMolsidominePotassium Channel BlockersGlyburideBasilar ArteryAdrenergic beta-AgonistsPulmonary ArteryPhenoxyacetatesomega-N-MethylarginineTime FactorsManometry