OuabainSodiumSodium-Potassium-Exchanging ATPaseStrophanthidinPotassiumCardiac GlycosidesSodium IsotopesBiological Transport, ActiveSodium ChannelsPurkinje FibersRubidiumDysprosiumMembrane PotentialsCardenolidesLithiumIon ChannelsSodium ChlorideBufanolidesCalciumVeratrineVeratridineSodium, DietaryAmilorideDigoxinPhotometryIntracellular FluidMonensinSodium Channel BlockersTetrodotoxinMyocardial ContractionErythrocytesSodium-Hydrogen AntiporterExtracellular SpaceAnuraBufo bufoSheepMyocardiumRubidium RadioisotopesOpossumsKineticsCardanolidesDigitoxigeninHeart Conduction SystemBiological TransportSodium-Calcium ExchangerPapillary MusclesGuinea PigsCell Membrane PermeabilityIon TransportHydrogen-Ion ConcentrationAdenosine TriphosphateAction PotentialsCell MembraneTime FactorsBenzofuransDogsMagnetic Resonance SpectroscopySaponinsHeartOsmolar ConcentrationLidocaineAcetanilidesDigitalisCardiac Complexes, PrematureMagnesiumKidney Tubules, ProximalElectrophysiologySodium Dodecyl SulfateEthers, CyclicSodium RadioisotopesHypertensionPerfusionSodium BicarbonateMicroelectrodesProton Pump InhibitorsRats, Sprague-DawleyDigitoxinTemperatureCells, CulturedEpithelial Sodium ChannelsRats, Inbred StrainsSodium Chloride, DietarySodium NitriteVanadiumAcrylamidesPotassium IsotopesAdenosine TriphosphatasesSodium CompoundsEnzyme InhibitorsIon Pumps4-NitrophenylphosphataseHeart VentriclesKidneyElectric StimulationSodium SalicylateSodium AzideInfusion PumpsCromolyn SodiumModels, BiologicalRabbits