title: The central effect of methionine-enkephalin on NK cell activity.
abstract: The central effect of opioid peptide on natural killer (NK) cell activity in BALB/c mice was investigated. Injection of methionine-enkephalin (Met-Enk), 0.02 microgram/mouse or 1 microgram/kg, directly into the cisterna magna (CM) of the brain, resulted in a significant enhancement of NK cell activity. This enhancement was blocked by opiate antagonists, naltrexone and quaternary naltrexone. The same dose of Met-Enk had no effect on NK cell activity when given to the mouse intraperitoneally or intravenously. Moreover, des-tyrosine-methionine-enkephalin injected into the CM at 1 microgram/kg, had no effect on NK cell activity. The results indicate that activation of an opioid-mediated pathway in the central nervous system is capable of activating the pathways that stimulate the NK cell response in the periphery.
authors.affiliation: Department of Biology, University of Alabama, Birmingham 35294.
authors.forename: C M
authors.initials: CM
authors.lastname: Hsueh
authors.forename: R N
authors.initials: RN
authors.lastname: Hiramoto
authors.forename: V K
authors.initials: VK
authors.lastname: Ghanta
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004744:Enkephalin, Methionine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology*; D005260:Female; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008845:Microinjections; D009271:Naltrexone / Q000494:pharmacology; D011070:Poly I-C / Q000494:pharmacology
chemical_list: D004744:Enkephalin, Methionine; D009271:Naltrexone; C029668:enkephalin-Met, des-Tyr(1)-; D011070:Poly I-C