Linked Life Data

1645852

Source:http://linkedlifedata.com/resource/pubmed/id/1645852

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-7-10
pubmed:abstractText
Melatonin receptors were characterized in the brains of three mammals (rabbit, horse and sheep) by an in vitro binding technique, using 2-[125I]iodomelatonin as labelled ligand. Although binding sites for melatonin have been described recently in several vertebrate species (including the sheep), the rabbit and the horse have not been the subject of investigation so far. Apart from characterization, the present report describes receptor distribution in a number of brain regions, thus allowing for direct interspecies comparison under the same methodological conditions. 2-[125I]iodomelatonin labelled high-affinity binding sites in crude membrane preparations from these species. A series of kinetic and saturation experiments revealed that the binding was rapid, stable, saturable, reversible, of high affinity (Kd in the low picomolar range) and low capacity (Bmax between 1 and 20 fmol/mg protein). The competition studies showed that the relative order of potency of a variety of indoles for inhibition of 2-[125I]iodomelatonin binding was as follows: 2-iodomelatonin greater than 6-chloromelatonin greater than melatonin much much greater than 5-methoxytryptophol greater than 5-methoxytryptamine, and that it was similar in the different brain regions. Prazosin, which has been reported as an extremely potent melatonin analog in the hamster brain, possessed no potency in all preparations from different regions in the three species under investigation. The regional distribution of the receptor showed insignificant species differences. Highest density was always recorded in the median eminence/pars tuberalis (ME/PT) area. Other regions (SCN, POA and certain cortical areas), showed lower, but significant, receptor content. Saturation and competition studies revealed that these binding sites were also of high affinity, low capacity and high specificity.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0028-3835
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
214-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Characterization and mapping of melatonin receptors in the brain of three mammalian species: rabbit, horse and sheep. A comparative in vitro binding study.
pubmed:affiliation
Department of Pharmacology, Faculty of Sciences, University of Milan, Italy.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't