Muscle ContractionMuscle, SkeletalSarcoplasmic ReticulumMuscle Fibers, SkeletalMusclesIsometric ContractionMuscle ProteinsTroponin CCalciumMuscle RelaxationTroponinRabbitsMyosinsMuscle FatigueTropomyosinMuscle, SmoothElectric StimulationCalcium-Transporting ATPasesRegional Blood FlowMuscle, Smooth, VascularMyocardial ContractionSarcoplasmic Reticulum Calcium-Transporting ATPasesMuscle DevelopmentMuscle Fibers, Fast-TwitchRyanodine Receptor Calcium Release ChannelCaffeineMuscle Fibers, Slow-TwitchMitochondria, MuscleMyocardiumMyofibrilsRyanodineAdenosine TriphosphateUterine ContractionKineticsCalsequestrinMuscle DenervationTime FactorsGuinea PigsRats, WistarElectromyographyRats, Sprague-DawleyAcetylcholineSatellite Cells, Skeletal MuscleCalcium SignalingDogsPotassium ChlorideMuscular DiseasesVasoconstrictionSarcolemmaDose-Response Relationship, DrugCalcium-Binding ProteinsMuscular AtrophyVasodilationCalcium ChannelsHindlimbTracheaMuscle CellsSarcomeresPapillary MusclesPhosphorylationMyocytes, Smooth MuscleMuscle, StriatedMembrane PotentialsHeartCells, CulturedGlycogenMuscle SpindlesQuadriceps MuscleMyosin Heavy ChainsModels, BiologicalPotassiumDiaphragmActinsEnzyme InhibitorsNitric OxideBiomechanical PhenomenaPhysical ExertionCa(2+) Mg(2+)-ATPaseVasoconstrictor AgentsMyosin Light ChainsRelaxationMuscle TonusExcitation Contraction CouplingRelaxation TherapyRNA, MessengerAdenosine TriphosphatasesAorta, ThoracicMuscle WeaknessPhenylephrineCalcium Channels, L-TypePeristalsisMyoblastsIsotonic ContractionMotor NeuronsVasodilator AgentsMagnesiumAnuraMolecular Sequence DataNeuromuscular JunctionSignal Transduction