Myocytes, CardiacMyocardiumRats, Sprague-DawleyPhenylephrineCells, CulturedHeartMyocardial ContractionReceptor, Endothelin AReceptors, EndothelinIsoproterenolReceptor, Endothelin BCalciumEndothelinsFibroblastsAnimals, NewbornHeart VentriclesEndothelin-1CardiomegalyRats, WistarAdrenergic alpha-AgonistsReceptors, Adrenergic, alpha-1Adrenergic beta-AgonistsMuscle CellsSarcolemmaSarcomeresSodium-Calcium ExchangerRNA, MessengerVasoconstrictor AgentsDose-Response Relationship, DrugReceptors, Adrenergic, betaAdrenergic alpha-1 Receptor AgonistsCardiotonic AgentsAtrial Natriuretic FactorCalcium SignalingCalcium Channels, L-TypeTime FactorsMitochondria, HeartMembrane PotentialsSarcoplasmic ReticulumPatch-Clamp TechniquesEnzyme InhibitorsRats, Inbred StrainsCell SizeAngiotensin IISignal TransductionCardiac OutputHypertrophyVasoconstrictionProtein Kinase CPotassium ChannelsNorepinephrineVentricular FunctionArrhythmias, CardiacModels, CardiovascularEndothelin-3Muscle ProteinsSarcoplasmic Reticulum Calcium-Transporting ATPasesReceptors, Adrenergic, alphaCaffeineTroponin IElectric StimulationCaveolin 3Action PotentialsPhosphorylationBlood PressureEnzyme ActivationHEPESNitric OxideCyclic Nucleotide Phosphodiesterases, Type 2Nitric Oxide SynthaseCalcium ChannelsGuinea PigsCyclic AMP-Dependent Protein KinasesPrazosinPeptides, CyclicEndothelin-2Myocardial IschemiaHeart AtriaMicroscopy, ConfocalKineticsElectrophysiologyGene Expression RegulationRabbitsCyclic AMPRyanodine Receptor Calcium Release ChannelSodium-Potassium-Exchanging ATPaseHeart RateBenzophenanthridinesGene ExpressionIndolesAdrenergic alpha-AntagonistsMuscle Fibers, SkeletalFluorescent DyesViper VenomsAdenosine TriphosphateDogsPhosphodiesterase InhibitorsBlotting, WesternSodium ChannelsMuscle, Smooth, Vascular