Short days induce changes in specific melatonin binding in hamster median eminence and anterior pituitary.
Autoradiography of 125I-melatonin binding to hamster brain sections revealed a competitive 125I-melatonin binding in median eminence only. Saturation studies on crude membrane fraction revealed high-affinity melatonin binding sites in median eminence (Kd = 59 pM) and anterior pituitary (Kd = 97 pM). In the hamsters maintained on LD 14:10, the concentration of the binding sites was 10.4 and 6.0 fmol/mg protein in median eminence and anterior pituitary respectively; long-term exposure to LD 8:16 decreased the concentration to less than a half.
Vanĕcek
J
J
Institute of Physiology, Czechoslovak Academy of Sciences, Prague, Czechoslovakia.
Janský
L
L
D000818:Animals; D002940:Circadian Rhythm; D006224:Cricetinae; D003624:Darkness; D007700:Kinetics; D008027:Light; D008297:Male; D008473:Median Eminence / Q000378:metabolism*; D008550:Melatonin / Q000378:metabolism*; D008647:Mesocricetus; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
D044094:Receptors, Melatonin; D017981:Receptors, Neurotransmitter; D008550:Melatonin