title: Behavioral effects of non-opioid fragments of beta-endorphin.
abstract: The opioid peptide beta-endorphin (beta E) is converted by brain enzymes to a variety of non-opioid peptide molecules. Several of these peptides specifically affect brain processes in a different manner as assessed in behavioral test procedures. The peptide beta E-(2-9) exhibits behavioral effects resembling psychostimulant drugs in certain aspects and potentiates apomorphine-induced stereotypy following peripheral and intrastriatal treatment. The peptide beta E-(10-16), like serotonin and antidepressant drugs antagonizes the behavioral effects of intra-accumbens injected melatonin. The peptide beta E-(6-17) induces several effects which resemble those of neuroleptic drugs, including an antipsychotic action, and may control the activity of specific dopaminergic systems present in the nucleus accumbens. Thus, non-opioid fragments of beta-endorphin may be involved in the modulation of neurotransmitter systems and consequently in brain homeostasis and possibly in psychopathological syndromes.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004723:Endorphins / Q000494:pharmacology*; D008550:Melatonin / Q000037:antagonists & inhibitors; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D013329:Structure-Activity Relationship; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D010446:Peptide Fragments; D001615:beta-Endorphin; D008550:Melatonin