Myocardial ContractionMuscle ContractionUterine ContractionMyocardiumHeartMyocytes, CardiacMyometriumVentricular Function, LeftMuscle, SmoothCalciumHeart VentriclesActomyosinCardiotonic AgentsMyosin Light ChainsDogsPapillary MusclesMyosin Type IISarcoplasmic Reticulum Calcium-Transporting ATPasesIsoproterenolVentricular FunctionHemodynamicsVentricular Pressurerho-Associated KinasesAdrenergic beta-AgonistsVasoconstrictionHeart RateRats, Sprague-DawleyHeterocyclic Compounds with 4 or More RingsDobutamineCalcium-Binding ProteinsCalcium SignalingSystoleBlood PressureDose-Response Relationship, DrugSarcoplasmic ReticulumGastrointestinal MotilitySodium-Calcium ExchangerHeart FailureActinsActin CytoskeletonPotassium ChlorideCardiomegalyStroke VolumeIsometric ContractionCardiac MyosinsTime FactorsEchocardiographyRats, WistarCells, CulturedOxytocicsDiaphragmSarcomeresReceptors, Adrenergic, betaUrinary BladderCardiac OutputDepression, ChemicalOxytocinExcitation Contraction CouplingElectric StimulationGuinea PigsPerfusionCoronary CirculationMyosinsCalcium Channels, L-TypeRabbitsVentricular Dysfunction, LeftVasoconstrictor AgentsPhenylephrinePressureCell SizeNonmuscle Myosin Type IIAMuscle, Smooth, VascularDiacetylMyocytes, Smooth MuscleCardiac VolumeThiadiazinesrhoA GTP-Binding ProteinMice, KnockoutCardiomyopathiesEnzyme InhibitorsDisease Models, AnimalAdrenergic beta-AntagonistsVascular ResistanceMyosin Heavy ChainsPhosphorylationMyosin-Light-Chain KinaseCardiomyopathy, DilatedNitric OxideStress FibersNorepinephrineCalcium-Transporting ATPasesMyographySignal TransductionStimulation, ChemicalAmidesLabor, ObstetricModels, CardiovascularCytoskeletonStress, MechanicalHeart Function Tests