title: [125I]iodomelatonin binding sites in spleens of birds and mammals.
abstract: The specific binding of [125I]iodomelatonin to duck spleen membrane preparations was studied in detail. These binding sites were stable, saturable, reversible and of high affinity. Scatchard analysis of the binding revealed a equilibrium binding constant (Kd) of 73.1 +/- 5.4 pM and a total number of binding sites (Bmax) of 3.64 +/- 1.38 fmol/mg protein. Studies on the relative binding capacities of [125I]iodomelatonin to the spleen in different species showed the following order: duck greater than chicken greater than guinea pig greater than pigeon greater than mouse. No binding site was detected in the rat spleen. The presence of [125I]iodomelatonin binding sites in the spleen of birds and mammals suggested a direct action of pineal melatonin on the immune system.
authors.affiliation: Department of Physiology, University of Hong Kong.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Yu
authors.forename: H
authors.initials: H
authors.lastname: Yuan
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: S F
authors.initials: SF
authors.lastname: Pang
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens; D010856:Columbidae; D004372:Ducks; D006168:Guinea Pigs; D007457:Iodine Radioisotopes; D007700:Kinetics; D008550:Melatonin / Q000378:metabolism*; D051379:Mice; D051381:Rats; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D013154:Spleen / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter; D008550:Melatonin