Enkephalins and endorphins.

Analgesics Animals Central Nervous System/analysis Digestive System/analysis Electrophysiology Endorphins/analysis,metabolism,pharmacology,physiology Enkephalins/analysis,metabolism,pharmacology,physiology Fluorescent Antibody Technique Humans Molecular Conformation Neurosecretory Systems/drug effects Neurotransmitter Agents/metabolism Pituitary Gland/analysis Radioimmunoassay Receptors, Opioid/metabolism Structure-Activity Relationship

Analgesics Endorphins Enkephalins Neurotransmitter Agents Receptors, Opioid