Relaxation TherapyMuscle RelaxationMuscle, SmoothMusclesMuscle ContractionMuscle, Smooth, VascularMuscle, SkeletalVasodilationMuscle ProteinsNitric OxideRelaxationMuscle Fibers, SkeletalAcetylcholineTracheaCyclic GMPVasodilator AgentsNitroprussideMuscle FatigueMuscle DevelopmentEndothelium, VascularElectric StimulationNitroarginineDeuteroporphyrinsBiological FactorsPenisDose-Response Relationship, DrugHSP20 Heat-Shock ProteinsRabbitsAorta, ThoracicMuscle TonusCalciumNeuromuscular BlockadeGuinea PigsNeuromuscular Nondepolarizing AgentsMuscle Fibers, Fast-TwitchOxadiazolesNitric Oxide DonorsMuscle DenervationIsoproterenolNitric Oxide SynthaseTime FactorsIsometric ContractionGuanylate CyclaseNG-Nitroarginine Methyl EsterMuscle Fibers, Slow-TwitchRats, Sprague-DawleyElectromyographyAortaOpossumsVasoactive Intestinal PeptideMyocytes, Smooth MuscleMyocardial ContractionRats, WistarCyclic GMP-Dependent Protein KinasesEnzyme InhibitorsDogsAnal CanalMitochondria, MuscleMagnetic Resonance SpectroscopyPapillary MusclesPhenylephrineNitroglycerinPenile ErectionArginineVasoconstrictionMesenteric ArteriesNeck MusclesOculomotor MusclesMuscle, Striated