title: Differential effects of beta-endorphin fragments on human natural killing.
abstract: The endogenous opiate peptide, beta-endorphin, has two effects on human natural killing (NK). Preincubation of effector lymphocytes with between 10(-7) and 10(-11) M beta-endorphin increases NK. Preincubation with lower concentrations results in a reduction in NK. Endorphin peptides containing an unmodified N-terminal sequence, and which are known to bind only to opiate receptors, increase NK. Sequences reported to bind only to nonopiate receptors reduce NK.
mesh_terms: D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004151:Dipeptides / Q000494:pharmacology; D004723:Endorphins / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D010446:Peptide Fragments / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D018822:alpha-Endorphin; D001615:beta-Endorphin / Q000031:analogs & derivatives / Q000494:pharmacology*
chemical_list: D004151:Dipeptides; D004723:Endorphins; D010446:Peptide Fragments; D001615:beta-Endorphin; D018822:alpha-Endorphin; C050079:lysyl-lysyl-glycyl-glutamic acid; C035101:N-acetyl-beta-endorphin