EnkephalinsEnkephalin, Ala(2)-MePhe(4)-Gly(5)-Enkephalin, LeucineEnkephalin, MethionineReceptors, Opioid, muEnkephalin, D-Penicillamine (2,5)-Enkephalin, Leucine-2-AlanineReceptors, Opioid, deltaReceptors, OpioidD-Ala(2),MePhe(4),Met(0)-ol-enkephalinEndorphinsNaloxoneNarcotic AntagonistsAnalgesics, OpioidMorphineReceptors, Opioid, kappaReceptors, Neurokinin-3NaltrexoneBenzomorphansEtorphineDiprenorphineNeurokinin BEthylketocyclazocineOpioid PeptidesTachykininsReceptors, TachykininCyclazocineNarcoticsAnalgesicsOligopeptidesDrug TolerancePyrrolidinesSubstance PNeurokinin AGuanosine 5'-O-(3-Thiotriphosphate)Receptors, Neurokinin-2SomatostatinDynorphinsDose-Response Relationship, DrugRats, Sprague-DawleySpinal CordCarboxypeptidase HBenzeneacetamidesPain Measurementbeta-EndorphinGuinea PigsNeurokinin-1 Receptor AntagonistsThiorphanReceptors, Neurokinin-1Protein PrecursorsMorphinansPiperidinesTioproninNeprilysinAdrenal MedullaIrisPeptide FragmentsBrainChromaffin GranulesAmino Acid SequenceIleumGlobus PallidusAminolevulinic AcidKineticsMolecular Sequence DataDihydromorphineVas DeferensAlanineRats, Inbred StrainsInjections, IntraventricularBinding, CompetitiveBenzamidesCarboxypeptidasesInjections, SpinalCorpus StriatumNeuronsStructure-Activity RelationshipBenzylidene CompoundsMyenteric Plexus