Direct action of melatonin on hen ovarian granulosa cells to lower responsiveness to luteinizing hormone.
The presence of a melatonin-binding component in the membrane fraction of the ovarian granulosa cells of hens that has characteristics of a receptor such as high affinity, limited capacity, reversible binding, and binding specificity was demonstrated by radioligand binding assays. When the cells were incubated in vitro with various concentrations of luteinizing hormone (LH) in the presence and absence of melatonin (1 and 5 nM), the dose-response curve for the LH-stimulated progesterone production was shifted to a higher concentration of LH: ED50 of LH was approximately two times greater in the presence of melatonin. The results suggest a direct action of melatonin on the ovarian granulosa cells of the hen to lower the responsiveness to LH for progesterone production.
Murayama
T
T
Department of Zootechnical Science, Tokyo University of Agriculture, Japan.
Kawashima
M
M
Takahashi
T
T
Yasuoka
T
T
Kuwayama
T
T
Tanaka
K
K
D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002645:Chickens / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects*; D007700:Kinetics; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008550:Melatonin / Q000378:metabolism / Q000494:pharmacology*; D011374:Progesterone / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D044094:Receptors, Melatonin
D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D044094:Receptors, Melatonin; D011374:Progesterone; D007986:Luteinizing Hormone; D008550:Melatonin