Hypertonic SolutionsGlucose Solution, HypertonicSaline Solution, HypertonicIsotonic SolutionsHypotonic SolutionsSolutionsOsmolar ConcentrationOsmosisSucroseOsmotic PressureMannitolRana temporariaTetracaineSodium ChlorideDiuretics, OsmoticAnuraRana pipiensTromethamineWater-Electrolyte BalancePotassiumMusclesMembrane PotentialsSodiumPotassium ChlorideMuscle ContractionCell Membrane PermeabilityChloridesGuinea PigsCaffeineGlycerolSulfatesSodium-Potassium-Chloride SymportersAction PotentialsMyofibrilsNeuromuscular JunctionCalciumUreaMuscle, SmoothCell SizeOuabainWaterElectrophysiologyTime FactorsElectric StimulationExtracellular SpaceAcetylcholinePharmaceutical SolutionsMicroscopy, Electron