Receptors, Opioid, kappaReceptors, Opioid, muReceptors, OpioidReceptors, Opioid, deltaAnalgesics, OpioidDynorphinsNaltrexoneNarcotic AntagonistsBenzeneacetamidesDiterpenes, ClerodaneMorphinansPyrrolidinesOpioid PeptidesEnkephalinsNaloxoneSalviaEnkephalin, Ala(2)-MePhe(4)-Gly(5)-Enkephalin, D-Penicillamine (2,5)-DiprenorphineDose-Response Relationship, DrugRadioligand AssayAnalgesicsNarcoticsEndorphinsPiperidinesLevorphanolMorphineRats, Sprague-DawleyPurinergic P2 Receptor AntagonistsEthylketocyclazocineGuinea PigsBinding, CompetitiveImmobility Response, TonicButorphanolCHO CellsOpioid-Related DisordersDopamine AntagonistsNalbuphineGuanosine 5'-O-(3-Thiotriphosphate)Nicotinic AntagonistsNeurokinin-1 Receptor AntagonistsSpiro CompoundsExcitatory Amino Acid AntagonistsDrug InteractionsTetrahydroisoquinolinesAnalgesics, Non-NarcoticRats, WistarLigandsImmunoglobulin kappa-ChainsReceptors, SerotoninCricetinaeBenzomorphansCyclazocinePainHistamine H2 AntagonistsMuscarinic AntagonistsPain MeasurementHormone AntagonistsBehavior, AnimalFentanylCricetulusHistamine AntagonistsStructure-Activity RelationshipDrug ToleranceAdrenergic alpha-AntagonistsGABA AntagonistsStereoisomerismPurinergic P1 Receptor AntagonistsSubstance Withdrawal SyndromeSelf AdministrationAdrenergic alpha-1 Receptor AntagonistsCocaineEtorphineEnkephalin, LeucineAdrenergic alpha-2 Receptor AntagonistsG-Protein-Coupled Receptor Kinase 3Serotonin AntagonistsBrainCell LineConditioning, OperantSpinal CordBuprenorphineAntipruriticsOligopeptidesMolecular Sequence DataReceptors, N-Methyl-D-AspartateInterleukin 1 Receptor Antagonist ProteinEnkephalin, Leucine-2-AlanineNeuronsBenzofuransMotor ActivityElectric StimulationSerotonin Receptor AgonistsReceptors, Histamine H3Protein PrecursorsGABA-A Receptor AntagonistsInjections, IntraventricularAmino Acid SequenceReceptors, Dopamine D2Diterpenes