Melatonin binding sites in the Harderian gland of Syrian hamsters: sexual differences and effect of castration.
The presence of specific melatonin binding sites in the Harderian gland of Syrian hamsters was studied using [125I]melatonin. Saturation binding experiments conducted with [125I]melatonin at 37 degrees C using Harderian glands of both male and female Syrian hamsters revealed a single nanomolar-affinity site. The dissociation constants (Kd) were 6.47 and 6.94 nM for males and females, respectively. The concentration of the binding sites was 7.58 fmol/mg protein for males and 13.50 fmol/mg protein for females. Castration of male hamsters resulted in a significant increase in [125I]melatonin binding sites while chronic melatonin administration did not modify the binding properties. The results confirm the presence of melatonin binding sites in the Harderian glands of rodents. The gender-associated differences found together with the effects of castration in male hamsters suggest an androgenic control in [125I]melatonin binding sites of the Syrian hamster Harderian gland.
Departamento de Morfologia y Biologia Celular, Universidad de Oviedo, Spain.
A
A
Menendez-Pelaez
M A
MA
Lopez-Gonzalez
J M
JM
Guerrero
D000818:Animals; D001665:Binding Sites; D002369:Castration; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D005260:Female; D006243:Harderian Gland / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000378:metabolism*; D008647:Mesocricetus; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D012737:Sex Factors
D007457:Iodine Radioisotopes; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter; D008550:Melatonin