title: Muramyl dipeptide mimicry in the regulation of murine macrophage activation by serotonin.
abstract: Muramyl peptides (MPs) are regulators of macrophage function. That the activities of MPs may be mediated by serotonin (5-HT) is supported by earlier work that demonstrated specific binding sites for MPs on macrophages that competitively bind 5-HT. Both mediators were also shown to enhance the production of superoxide anion (an antibacterial agent) by these cells. We now report on two additional macrophage activation phenomena affected by 5-HT: phagocytosis and induction of tumor necrosis factor alpha (TNF) mRNA. Serotonin acts as a muramyl peptide-like agonist by increasing phagocytosis of tubercle bacilli by murine peritoneal macrophages, and as a partial agonist/antagonist in the induction of mRNA for tumor necrosis factor. These observations provide further evidence for a serotonergic involvement in some of the physiological responses to MPs.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: M
authors.initials: M
authors.lastname: Polanski
authors.forename: M W
authors.initials: MW
authors.lastname: Vermeulen
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: M L
authors.initials: ML
authors.lastname: Karnovsky
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000276:immunology / Q000494:pharmacology*; D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D007375:Interleukin-1 / Q000235:genetics; D007457:Iodine Radioisotopes; D008262:Macrophage Activation / Q000187:drug effects*; D008297:Male; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects; D012701:Serotonin / Q000276:immunology / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000235:genetics
chemical_list: D000276:Adjuvants, Immunologic; D007375:Interleukin-1; D007457:Iodine Radioisotopes; D014409:Tumor Necrosis Factor-alpha; D012701:Serotonin; D000119:Acetylmuramyl-Alanyl-Isoglutamine