Constant light exposure increases 2-[125I]iodomelatonin binding sites in the guinea pig spleen.
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.
Poon
A M
AM
Department of Physiology, University of Hong Kong.
Pang
S F
SF
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
D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter; C044556:2-iodomelatonin; D008550:Melatonin