title: Diurnal variation and binding characteristics of melatonin in the mouse brain and gastrointestinal tissues.
abstract: 1. Compared to night time values, levels of melatonin (M), determined by specific RIA, were lower in the brain and the duodenum-jejunum segment of mice sacrificed in mid-photophase. In other parts of the gut no significant diurnal difference was observed. 2. Highest daytime levels were detected in the stomach (569 pg/ml), lowest in the brain (62 pg/ml). 3. Preliminary studies indicate the presence of specific binding sites for [125I]iodo-melatonin in the colon, ileum, jejunum, stomach and brain. These sites, which exhibit an affinity of about 1 nM, may be involved in mediating the gastrointestinal and central effects of melatonin in this species.
authors.affiliation: Department of Zoology, University of Guelph, Ontario, Canada.
authors.forename: G A
authors.initials: GA
authors.lastname: Bubenik
authors.forename: L P
authors.initials: LP
authors.lastname: Niles
authors.forename: S F
authors.initials: SF
authors.lastname: Pang
authors.forename: P J
authors.initials: PJ
authors.lastname: Pentney
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D004064:Digestive System / Q000378:metabolism*; D005260:Female; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D051379:Mice; D011863:Radioimmunoassay; D011869:Radioligand Assay
chemical_list: D008550:Melatonin