title: Stimulation of murine splenocytes by melatonin and methoxytryptamine.
abstract: Male C57 mice kept under a 14:10 (L:D) photoperiod received vehicle (VEH), melatonin (MEL) and methoxytryptamine (MTA) in the drinking water for 2 weeks. Splenocytes from MEL-treated mice showed an augmented mitogenic response to concanavalin A and lipopolysaccharide (LPS) while splenocytes from MTA-treated mice demonstrated an enhanced mitogenic response to LPS when compared to the VEH-treated control. Splenocytes from MEL-treated and MTA-treated mice also produced higher levels of gamma interferon and interleukin-2. Lymphokines prepared from splenocytes of MEL-treated mice stimulated peritoneal macrophages to produce more nitrite than those from splenocytes of MTA-treated and control mice, suggesting that MEL had a stronger stimulating effect on the lymphocytes than MTA. Understimulation of lymphokines from MEL-treated mice, peritoneal macrophages from MTA-treated mice produced a greater inhibition of the growth of murine mastocytoma P815 cells than that produced by macrophages from control and MEL-treated mice, suggesting that MTA was more potent than MEL in rendering the macrophages responsive to lymphokines. The results point to immunostimulatory actions of the pineal indoles MEL and MTA.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N. T.
authors.forename: S F
authors.initials: SF
authors.lastname: Sze
authors.forename: W K
authors.initials: WK
authors.lastname: Liu
authors.forename: T B
authors.initials: TB
authors.lastname: Ng
mesh_terms: D008735:5-Methoxytryptamine / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008222:Lymphokines / Q000032:analysis / Q000096:biosynthesis; D017737:Macrophages, Peritoneal / Q000187:drug effects; D008297:Male; D008415:Mastocytosis / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000494:pharmacology; D009573:Nitrites / Q000378:metabolism; D013154:Spleen / Q000166:cytology* / Q000187:drug effects; D013268:Stimulation, Chemical
chemical_list: D007376:Interleukin-2; D008070:Lipopolysaccharides; D008222:Lymphokines; D008934:Mitogens; D009573:Nitrites; D003208:Concanavalin A; D008735:5-Methoxytryptamine; D007371:Interferon-gamma; D008550:Melatonin