title: Opioid peptides modulate production of interferon gamma by human mononuclear cells.
abstract: The opioid neuropeptides have previously been shown to bind to and affect leukocyte function including lymphocyte proliferation, NK-cell activity, mononuclear cell chemotaxis, immunoglobulin synthesis, and lymphokine production. The effect of the opioid peptides beta-endorphin and Met-enkephalin on interferon gamma (IFN) production by concanavalin A-stimulated human mononuclear cells was examined. Both beta-endorphin and Met-enkephalin enhanced IFN production by the majority of donor mononuclear cells tested and did so at concentrations between 10(-14) and 10(-10) M. When 10(-12) M beta-endorphin or Met-enkephalin were included in concanavalin A-stimulated mononuclear cell cultures, IFN concentrations were significantly enhanced to 205 +/- 45 and 252 +/- 67% of control, respectively. Although the majority of cell preparations tested exhibited an enhanced production of IFN in response to these opioid peptides, some did not. When beta-endorphin or Met-enkephalin were utilized at 10(-11) M, 10 of 15 and 7 of 11 responded with IFN production greater than 20% above the control (untreated) level. There was not an absolute correlation between an enhanced response to beta-endorphin and Met-enkephalin, suggesting the presence of multiple receptor types on these cells for opioids. The opioid receptor antagonist, naloxone, did not significantly prevent the opiate effect. When 10(-8) M naloxone was included in cultures containing 10(-12) M beta-endorphin or Met-enkephalin no significant inhibition of the effect of either opioid on IFN production was observed.
mesh_terms: D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004723:Endorphins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D009270:Naloxone / Q000494:pharmacology; D011957:Receptors, Opioid / Q000145:classification / Q000187:drug effects; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D011957:Receptors, Opioid; D003208:Concanavalin A; D009270:Naloxone; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D007371:Interferon-gamma