Hindlimb SuspensionHindlimbMuscular AtrophyMuscle, SkeletalAtrophyMuscle Fibers, Slow-TwitchMuscle Fibers, Fast-TwitchMuscle ProteinsMuscle Fibers, SkeletalMusclesWeightlessness SimulationWeight-BearingMyosin Heavy ChainsMuscle ContractionSuspensionsOrgan SizeRats, Sprague-DawleyRats, WistarSKP Cullin F-Box Protein LigasesMuscle DenervationMuscular Disorders, AtrophicPerfusionTime FactorsAdaptation, PhysiologicalMyostatinMuscle, SmoothRegional Blood FlowMuscle DevelopmentIschemiaMuscle, Smooth, VascularBody WeightMuscular Atrophy, SpinalImmobilizationSciatic NerveRNA, MessengerOptic AtrophyMuscle WeaknessMuscle FatiguePhysical Conditioning, AnimalMitochondria, MuscleSatellite Cells, Skeletal MuscleSpinal Muscular Atrophies of ChildhoodElectric StimulationCachexiaUbiquitin-Protein LigasesOxygen ConsumptionLactic AcidMultiple System AtrophyQuadriceps MuscleElectromyographyMuscular DiseasesInsulinRats, Inbred StrainsGlycogenDisease Models, AnimalIsometric ContractionGlucoseVasoconstrictionNG-Nitroarginine Methyl EsterSpace FlightMyocytes, Smooth MuscleMyoblastsMuscle CellsMotor NeuronsMyofibrilsSarcopeniaBed Rest