DiastoleVentricular PressureMyocardial ContractionVentricular Function, LeftEchocardiography, Doppler, ColorMuscle RelaxationEchocardiography, DopplerMyocardiumHeartVentricular Dysfunction, LeftRelaxationRelaxation TherapyVasodilationAcetylcholineNitric OxideVasodilator AgentsMuscle ContractionEndothelium, VascularNitroarginineBiological FactorsMuscle, SmoothNitroprussideMuscle, Smooth, VascularMagnetic Resonance SpectroscopyAorta, ThoracicMesenteric ArteriesCyclic GMPNG-Nitroarginine Methyl EsterVasoconstrictor AgentsGastric FundusDose-Response Relationship, DrugMethylene BlueNitric Oxide SynthaseIndomethacinCharybdotoxinPenisOxadiazolesArginineElectric StimulationPhenylephrineApamin15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic AcidTracheaRabbitsVasoconstrictionBradykininAortaPotassium ChlorideEnzyme InhibitorsEsophageal Sphincter, LowerGuanylate CyclaseNitric Oxide DonorsMuscle TonusCalciumCoronary VesselsGuinea PigsRats, WistarDogsIsoproterenolArteriesVasoactive Intestinal PeptideEsophagogastric JunctionSwineQuinoxalinesNitroglycerinNuclear Magnetic Resonance, BiomolecularEndothelium-Dependent Relaxing FactorsRats, Sprague-DawleyCromakalimNorepinephrineMolsidominePotassium Channel BlockersNitric Oxide Synthase Type IIIGlyburideBasilar ArteryAdrenergic beta-AgonistsPulmonary ArteryPhenoxyacetatesomega-N-MethylarginineTime FactorsManometryGuanethidinePotassium ChannelsKineticsPressureCalcimycinAtropineDiazonium CompoundsPotassiumSpin LabelsRats, Inbred WKYViscosityCyclooxygenase InhibitorsWaterMathematicsMembrane PotentialsPurinonesProstaglandin Endoperoxides, SyntheticElasticityCarbachol