Biomaterial Database

[125I]melatonin binding sites in membrane preparations of quail brain: characteristics and diurnal variations. 1990

H Yuan, and S F Pang

Department of Physiology, University of Hong Kong.

The binding of [125I]melatonin, a labelled ligand of melatonin, to quail brain membrane preparations was studied. Kinetic studies indicated that the binding of [125I]melatonin to membrane preparations of quail brains collected at mid-light was time-dependent and reversible. The Kd value determined from kinetic analysis was 614 pmol/l, similar to the Kd 705 +/- 81 pmol/l obtained from saturation experiments. The [125I]melatonin binding sites in quail brain membrane had the following order of pharmacological affinities: melatonin greater than 6-chloromelatonin greater than N-acetylserotonin greater than 5-hydroxytryptamine much greater than 5-methoxytryptophol, tryptamine, L-tryptophan, 5-hydroxytryptophan, 5-hydroxyindole-3-acetic acid, 1-acetylindole-3-carboxaldehyde, 3-acetylindole. Compounds known to act on serotonergic, adrenergic or acetylcholinergic receptors were inactive as compared with melatonin. Our results demonstrated the presence of specific melatonin binding sites in the quail brain membrane preparations. In addition, saturation studies demonstrated that [125I]melatonin binding sites in quail brain membrane preparations were 42% higher at mid-light (39.6 +/- 2.2 fmol/mg protein) than at mid-dark (22.6 +/- 2.5 fmol/mg protein), with no significant variation in their binding affinities.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D008550	Melatonin	A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
D011784	Quail	Common name for two distinct groups of BIRDS in the order GALLIFORMES: the New World or American quails of the family Odontophoridae and the Old World quails in the genus COTURNIX, family Phasianidae.	Quails
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D003370	Coturnix	A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.	Japanese Quail,Coturnix japonica,Japanese Quails,Quail, Japanese,Quails, Japanese
D003624	Darkness	The absence of light.	Darknesses
D000220	Adaptation, Biological	Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.	Adaptation, Biologic,Biological Adaptation,Biologic Adaptation