Linked Life Data

8773460

Source:http://linkedlifedata.com/resource/pubmed/id/8773460

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
1997-2-4
pubmed:abstractText
We now describe the preparation and characterization of a novel radioligand, 2-[125I]iodo-5-methoxy-carbonylamino-N-acetyltryptamine (2-[125I]MCA-NAT), with high affinity and pharmacological selectivity for melatonin ML2 receptor sites. 2-[125I]MCA-NAT was prepared by introducing an [125I]iodine molecule on carbon 2 of 5-MCA-NAT (5-methoxycarbonylamino N-acetyltryptamine), a selective melatonin ML2 receptor ligand. The specific binding (88%) of 2-[125I]MCA-NAT (50 pM) to whole washed hamster brain membranes showed rapid kinetics of association/dissociation, and was of high affinity and saturable (Kd value = 116 +/- 14 pM; Bmax value = 15.5 +/- 1.8 fmol/mg protein, n = 3). 2-[125I]MCA-NAT showed no affinity for melatonin ML1 receptors of chicken retina. Competition curves of various melatonin analogues for 2-[125I]MCA-NAT binding to hamster brain, testes and kidney were monophasic and showed a pharmacological order of affinities (Ki values for brain, nM) identical to that of the ML2 sites [2-iodomelatonin (0.77) > 6-chloro-2-methyl-melatonin (2.56) > 6-chloromelatonin (6.8) > prazosin (21.7) > or = N-acetylserotonin (23.3 nM) > or = 5-MCA-NAT (29.5) > or = melatonin (83.9) > luzindole (1687) > serotonin (2120)]. Affinity constants for competition of melatonin analogues on [125I]MCA-NAT binding to hamster brain, testes, and kidney correlated significantly [r = 0.962, P < 0.001, n = 9; r = 0.982, P < 0.0001, n = 13; r = 0.975, P < 0.0001, n = 9, respectively) with the affinities determined on 2-[125I]iodomelatonin binding to ML2 sites (hamster brain) but not to ML1 sites (chicken retina, r = 0.33, P > 0.05, n = 16). In conclusion, 2-[125I]MCA-NAT is a specific radioligand for the identification and characterization of ML2 binding sites in brain and peripheral tissues.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
301
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-68
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8773460-Animals, pubmed-meshheading:8773460-Brain, pubmed-meshheading:8773460-Chickens, pubmed-meshheading:8773460-Cricetinae, pubmed-meshheading:8773460-Guinea Pigs, pubmed-meshheading:8773460-Iodine Radioisotopes, pubmed-meshheading:8773460-Kinetics, pubmed-meshheading:8773460-Ligands, pubmed-meshheading:8773460-Membranes, pubmed-meshheading:8773460-Mesocricetus, pubmed-meshheading:8773460-Mice, pubmed-meshheading:8773460-Mice, Inbred C3H, pubmed-meshheading:8773460-Phodopus, pubmed-meshheading:8773460-Rabbits, pubmed-meshheading:8773460-Rats, pubmed-meshheading:8773460-Rats, Sprague-Dawley, pubmed-meshheading:8773460-Receptors, Cell Surface, pubmed-meshheading:8773460-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:8773460-Receptors, Melatonin, pubmed-meshheading:8773460-Retina, pubmed-meshheading:8773460-Tryptamines
pubmed:year
1996
pubmed:articleTitle
2-[125I]iodo-5-methoxycarbonylamino-N-acetyltryptamine: a selective radioligand for the characterization of melatonin ML2 binding sites.
pubmed:affiliation
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, Chicago 60611-3008, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't