title: Adrenocorticotrophic hormone fragments mimic the effect of morphine in vitro.
abstract: 1 Fragments of the N terminal part of adrenocorticotrophic hormone (ACTH) inhibited the electrically evoked contractions of the mouse vas deferens. This inhibition could be antagonized by naloxone. 2 The same fragments displaced radiolabelled morphine from morphine antiserum. 3 Structure-activity relationship studies showed that in both assay systems the active core is located within the sequence ACTH 7--10. 4 It is postulated that the Trp9 residue and the peptide bond between Trp9 and Gly10 are particularly important for interaction of ACTH fragments with morphine receptors.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000906:Antibodies; D001667:Binding, Competitive; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009020:Morphine / Q000276:immunology / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D000906:Antibodies; D010446:Peptide Fragments; D009020:Morphine; D000324:Adrenocorticotropic Hormone