title: Iodinated melatonin mimics melatonin action and reveals discrete binding sites in fetal brain.
abstract: Iodinated melatonin was used to study melatonin sites of action in brain. Iodomelatonin mimicked the effects of melatonin on reproductive development in Djungarian hamster fetuses. 125I-melatonin injected into the dam was recovered from fetal brain. In vitro autoradiographic studies revealed a remarkably discrete distribution of competitive 125I-melatonin-binding sites in the fetal brain, with binding in median eminence/arcuate nucleus area greater than suprachiasmatic nucleus greater than pineal gland much greater than anterior pituitary gland much greater than preoptic area. 125I-melatonin promises to be a useful tool for understanding the sites and mechanism of action of melatonin.
authors.affiliation: Laboratory of Developmental Chronobiology, Children's Service, Massachusetts General Hospital, Boston 02114.
authors.forename: D R
authors.initials: DR
authors.lastname: Weaver
authors.forename: M A
authors.initials: MA
authors.lastname: Namboodiri
authors.forename: S M
authors.initials: SM
authors.lastname: Reppert
mesh_terms: D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism* / Q000528:radiation effects; D006224:Cricetinae; D005260:Female; D005333:Fetus / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism; D008550:Melatonin / Q000031:analogs & derivatives* / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D011247:Pregnancy; D014018:Tissue Distribution
chemical_list: C044556:2-iodomelatonin; D008550:Melatonin