title: Modulatory effects of beta-endorphin on interferon-gamma production by cultured peripheral blood mononuclear cells: heterogeneity among donors and the influence of culture medium.
abstract: The stress-responsive neuropeptide beta-endorphin (beta-END) has been shown to either enhance or suppress interferon-gamma (IFN-gamma) production by mitogen stimulated peripheral blood mononuclear cells (PBMNC) in vitro. In this study, we investigated whether donor selection and the medium used for cell culture influenced the modulatory effect of beta-END on the IFN-gamma production by PBMNC. Considerable variation of the effect of beta-END on IFN-gamma production was observed in individuals who underwent multiple testing. Suppression of IFN-gamma was significantly greater in 16 male donors (29 +/- 6.0%) compared to 8 female donors (1.5 +/- 6.4%) when PBMNC were preincubated for 3 h with beta-END followed by concanavalin A stimulation for 72 h in medium containing 20% fetal bovine serum (FBS). Lowering the concentration of FBS resulted in enhanced production of IFN-gamma by PBMNC exposed to beta-END. Arachidonic acid or beta-END added separately to medium containing 3% autologous serum produced no suppression of IFN-gamma, but when added together resulted in significant suppression. This observation provides support for the hypothesis that beta-END achieves its suppressive effect on IFN-gamma via a mechanism involving arachidonic acid metabolism. We conclude that the modulatory effect of beta-END on IFN-gamma production by PBMNC is both donor and medium dependent.
authors.affiliation: Department of Medicine, Hennepin County Medical Center, Minneapolis, Minnesota.
authors.forename: C F
authors.initials: CF
authors.lastname: Brummitt
authors.forename: B M
authors.initials: BM
authors.lastname: Sharp
authors.forename: G
authors.initials: G
authors.lastname: Gekker
authors.forename: W F
authors.initials: WF
authors.lastname: Keane
authors.forename: P K
authors.initials: PK
authors.lastname: Peterson
mesh_terms: D000328:Adult; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001782:Blood Donors; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D001615:beta-Endorphin / Q000494:pharmacology*
chemical_list: D001095:Arachidonic Acids; D003470:Culture Media; D003208:Concanavalin A; D016718:Arachidonic Acid; D001615:beta-Endorphin; D007371:Interferon-gamma