title: Constant light exposure increases 2-[125I]iodomelatonin binding sites in the guinea pig spleen.
abstract: The effect of constant light exposure on 2-[125I]iodomelatonin binding sites in the guinea pig spleen was investigated. Guinea pigs exposed to constant light for 2-3 weeks showed an increase in the number of splenic 2-[125I]iodomelatonin binding sites, without any difference in the binding affinity, in comparison to animals kept under 12 h light/12 h darkness condition, whereas the splenic indices were similar in both groups. This light dependence of the splenic 2-[125I]iodomelatonin binding sites suggests that the binding sites are melatonin receptors and that the light dependent immunomodulatory effect of melatonin is mediated via a direct action on the lymphoid tissue.
authors.affiliation: Department of Physiology, University of Hong Kong.
authors.forename: A M
authors.initials: AM
authors.lastname: Poon
authors.forename: S F
authors.initials: SF
authors.lastname: Pang
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006168:Guinea Pigs; D007700:Kinetics; D008027:Light; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000378:metabolism; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter / Q000378:metabolism* / Q000528:radiation effects; D013154:Spleen / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter; C044556:2-iodomelatonin; D008550:Melatonin