Characterization of central melatonin receptors using 125I-melatonin.
The binding of 125I-melatonin, a potent analog of melatonin, to rat brain synaptosomal preparations was investigated. 125I-melatonin bound with high affinity (Kd = 38 nM) to a single class of sites (Bmax = 81 fmol/mg protein). Kinetic studies indicated that binding was time-dependent and reversible. Specific 125I-melatonin binding was inhibited by melatonin, and was unaffected by other structurally related compounds including serotonin. Binding of 125I-melatonin was greatly reduced if the synaptosomal preparations were pretreated by heat or trypsin but was unaffected by freeze-thawing. These results suggest that 125I-melatonin may serve as a valuable probe for studying melatonin receptors.
M
M
Laudon
N
N
Zisapel
D000818:Animals; D001921:Brain / Q000378:metabolism*; D005615:Freezing; D006358:Hot Temperature; D006897:Hydroxyindoleacetic Acid / Q000494:pharmacology; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D044094:Receptors, Melatonin; D012701:Serotonin / Q000494:pharmacology; D013574:Synaptosomes / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology
D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D044094:Receptors, Melatonin; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; C044556:2-iodomelatonin; D014357:Trypsin; D008550:Melatonin