Localization and quantification of high-affinity melatonin binding sites in Rana pipiens retina.
Melatonin binding was localized to the inner plexiform layer (IPL) of the frog retina by in vitro autoradiography, using 2-125I-melatonin as the radioligand. Radioreceptor binding assays of frog retinal homogenate demonstrated saturable melatonin binding. Scatchard analysis revealed a single population of binding sites with an apparent dissociation constant (Kd) of 125 pM, with a Bmax of 0.138 fmoles/mg of protein. These results suggest that high-affinity melatonin binding sites are present in the IPL of the frog retina, which may reflect the presence of melatonin receptors in this synaptic layer.
Wiechmann
A F
AF
Department of Neurobiology and Anatomy, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1010.
Wirsig-Wiechmann
C R
CR
D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D002452:Cell Count; D007457:Iodine Radioisotopes; D007700:Kinetics; D008550:Melatonin / Q000032:analysis / Q000378:metabolism*; D011869:Radioligand Assay; D011894:Rana pipiens; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D012160:Retina / Q000378:metabolism*
D007457:Iodine Radioisotopes; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter; D008550:Melatonin