EnkephalinsEnkephalin, Ala(2)-MePhe(4)-Gly(5)-Enkephalin, LeucineEnkephalin, MethionineEnkephalin, D-Penicillamine (2,5)-Enkephalin, Leucine-2-AlanineEndorphinsReceptors, Opioid, muReceptors, OpioidReceptors, Opioid, deltaReceptors, Neurokinin-3NaloxoneNeurokinin BEthylketocyclazocineTachykininsReceptors, TachykininCyclazocineReceptors, Opioid, kappaD-Ala(2),MePhe(4),Met(0)-ol-enkephalinNarcotic AntagonistsSubstance PNeurokinin AReceptors, Neurokinin-2MorphineDynorphinsAnalgesics, OpioidDopamine AgonistsRNA, Transfer, GlyBenzeneacetamidesNaltrexoneBenzomorphansGuinea PigsDose-Response Relationship, DrugCarboxypeptidase HOpioid Peptidesbeta-EndorphinNarcoticsDiprenorphineOligopeptidesNeurokinin-1 Receptor AntagonistsGlycineEtorphineGABA AgonistsPiperidinesAmino Acid SequenceRats, Sprague-DawleyReceptors, Neurokinin-1Molecular Sequence DataPurinergic P1 Receptor AgonistsMorphinansPyrrolidinesKineticsThiorphanMuscarinic AgonistsPeptide FragmentsProtein PrecursorsNicotinic AgonistsRadioligand AssayBinding, CompetitiveAnalgesicsAdrenergic AgonistsAdrenergic alpha-2 Receptor AgonistsSerotonin 5-HT2 Receptor AgonistsStructure-Activity RelationshipBrainNeprilysinAdrenal MedullaIleumAlanineTioproninSerotonin 5-HT1 Receptor AgonistsHistamine AgonistsIrisSomatostatinPurinergic P2 Receptor AgonistsAdrenergic beta-AgonistsPeptidesNeuronsBenzylidene CompoundsRats, Inbred StrainsVas DeferensMutagenesis, Site-DirectedLigandsCyclic AMPGABA-A Receptor AgonistsGuanosine 5'-O-(3-Thiotriphosphate)Models, MolecularBinding SitesInjections, IntraventricularGlobus PallidusChromaffin GranulesCholinergic AgonistsBenzamidesAdenosine A1 Receptor AgonistsCell LineAmino Acid SubstitutionCorpus StriatumCells, CulturedProtein ConformationAdrenergic alpha-Agonists