A peptide-like substance from pituitary that acts like morphine. 2. Purification and properties.

Animals Binding, Competitive Biological Assay Brain/metabolism Carboxypeptidases Cattle Chromatography, Ion Exchange Chymotrypsin Etorphine/antagonists & inhibitors Guinea Pigs Ileum/drug effects Molecular Weight Morphine/metabolism,pharmacology Morphine Derivatives/pharmacology Naloxone/antagonists & inhibitors,pharmacology Peptides/isolation & purification,pharmacology Pituitary Gland/analysis Receptors, Drug Sodium/pharmacology Swine Trypsin

Morphine Derivatives Peptides Receptors, Drug Naloxone Etorphine Morphine Sodium Carboxypeptidases Chymotrypsin Trypsin