The chick retinal melatonin receptor revisited: localization and modulation of agonist binding with guanine nucleotides.

The chick retinal melatonin receptor was localized to the inner plexiform layer using 2-125I-melatonin and in vitro autoradiographic techniques. This receptor was of high affinity (Kd 19.8 pM) and specificity and showed guanine nucleotide modulation of agonist binding. It thus behaves similarly to other recently characterized high affinity melatonin receptors.