Pharmacological characterization of melatonin binding sites in Syrian hamster hypothalamus

The radioligand [125I]iodomelatonin was used to study melatonin binding sites in Syrian hamster hypothalamus and hippocampus. Scatchard analysis revealed a single binding site with nanomolar affinity in hypothalamus (Kd = 1.8 +/- 0.3 nM, Bmax = 75 +/- 7 fmol/mg protein; n = 4) and hippocampus (Kd = 2.2 +/- 0.2 nM, Bmax = 49 +/- 5 fmol/mg protein; n = 4). The Kd value calculated from the association and dissociation rate constants in …