EnkephalinsEnkephalin, Ala(2)-MePhe(4)-Gly(5)-Enkephalin, LeucineEnkephalin, MethionineEnkephalin, D-Penicillamine (2,5)-Enkephalin, Leucine-2-AlanineEndorphinsReceptors, Opioid, muReceptors, OpioidCell MembraneReceptors, Opioid, deltaReceptors, Neurokinin-3MembranesNaloxoneReceptors, Opioid, kappaMembrane LipidsNeurokinin BEthylketocyclazocineMembrane PotentialsPurinergic P1 Receptor AgonistsIntracellular MembranesReceptors, TachykininTachykininsCyclazocineSerotonin Receptor AgonistsDopamine AgonistsDose-Response Relationship, DrugD-Ala(2),MePhe(4),Met(0)-ol-enkephalinNarcotic AntagonistsSubstance PMembranes, ArtificialSerotonin 5-HT1 Receptor AgonistsNeurokinin AReceptors, Neurokinin-2MorphineSerotonin 5-HT2 Receptor AgonistsReceptors, Cell SurfaceAdenosine A1 Receptor AgonistsRats, Sprague-DawleyGuinea PigsAmino Acid SequenceMolecular Sequence DataDynorphinsErythrocyte MembraneAnalgesics, OpioidCell LineMembrane FluidityCells, CulturedKineticsBenzeneacetamidesProtein BindingBinding, CompetitiveCell Membrane PermeabilityCalciumSignal TransductionGABA AgonistsAdenosine A2 Receptor AgonistsNaltrexoneGABA-A Receptor AgonistsOligopeptidesGABA-B Receptor AgonistsBenzomorphansCannabinoid Receptor AgonistsSerotonin 5-HT4 Receptor AgonistsPiperidinesBinding SitesBasement MembranePurinergic P2 Receptor AgonistsOpioid PeptidesRadioligand AssayPeptide FragmentsRNA, Transfer, GlyPeptidesNeuronsLigandsAdrenergic alpha-2 Receptor AgonistsRats, WistarPyrrolidinesNarcoticsMembrane Transport ProteinsMutationStructure-Activity RelationshipModels, MolecularMembrane GlycoproteinsCyclic AMPCricetinaeNeurokinin-1 Receptor AntagonistsAdenosine A3 Receptor AgonistsHistamine AgonistsGlycineCarboxypeptidase HTime FactorsProtein TransportAdenosineReceptors, DrugMuscarinic AgonistsGTP-Binding ProteinsProtein ConformationProtein Structure, Tertiarybeta-Endorphin