title: Immunologic action of [Met5]enkephalin fragments.
abstract: The aim of this study was to evaluate the effects of [Met5]enkephalin, des-Met-[Met5]enkephalin, des-Tyr-[Met5]enkephalin, and Tyr-Gly-Gly on natural killer cytotoxic activity and on concanavalin A- and lipopolysaccharide-stimulated proliferation of B and T cells in mice. Single i.p. injections of [Met5]enkephalin, des-Met-[Met5]enkephalin, and Tyr-Gly-Gly increased both natural killer cytotoxicity and proliferation of mitogen-stimulated B and T cells. These effects were inhibited by naloxone pretreatment, which suggests the opioid mechanism of the peptides studied. The rate of lymphocytic proliferation increases not only after single injection of [Met5]enkephalin or its metabolites, but also after 3 or 7 days of treatment. Apart from the functional effects, [Met5]enkephalin, des-Met-[Met5]enkephalin, and Tyr-Gly-Gly increased the percentages of natural killer cells and T cells. The results of this study suggest that the immunomodulatory action of [Met5]enkephalin may be mediated or enhanced by its N-terminal metabolites des-Met-[Met5]enkephalin and Tyr-Gly-Gly.
authors.affiliation: Department of Clinical Pharmacology, Silesian University School of Medicine, Katowice, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Kowalski
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000494:pharmacology*; D005260:Female; D007111:Immunity, Cellular / Q000187:drug effects*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D003208:Concanavalin A; D004744:Enkephalin, Methionine; C029668:enkephalin-Met, des-Tyr(1)-