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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-7-3
pubmed:abstractText
Mechanisms underlying the daily and photoperiodic variations in mt(1) melatonin receptors were investigated in the pars tuberalis (PT) and suprachiasmatic nuclei (SCN) of Siberian and Syrian hamsters. Whatever its daily profile, melatonin receptor density was strongly increased in both structures and species after constant light exposure or pinealectomy, and decreased after a single melatonin injection, indicating melatonin involvement in the daily regulation of the receptor protein. This was confirmed by a strong inverse correlation between melatonin binding capacity and plasma melatonin concentration. In contrast, regulation of mt(1) mRNA appeared more complex. The circadian clock, the light/dark cycle and melatonin are all implicated in mt(1) gene daily fluctuations, but the extent of their involvement depends upon the structure and the species studied. The photoperiodic decrease in melatonin receptor density observed in short photoperiod (PT of the two hamster species and Syrian hamster SCN) seems to be the consequence of a long-term mt(1) gene repression induced by the lengthening of the melatonin peak. Altogether, these results show that during daily variations, mt(1) melatonin receptor mRNA and protein are differentially regulated, while at the photoperiodic level, the mt(1) protein status depends on mRNA transcription.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0028-3835
pubmed:author
pubmed:copyrightInfo
Copyright 2001 S. Karger AG, Basel
pubmed:issnType
Print
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
55-68
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11435758-Animals, pubmed-meshheading:11435758-Antisense Elements (Genetics), pubmed-meshheading:11435758-Biological Clocks, pubmed-meshheading:11435758-Circadian Rhythm, pubmed-meshheading:11435758-Cricetinae, pubmed-meshheading:11435758-In Situ Hybridization, pubmed-meshheading:11435758-Male, pubmed-meshheading:11435758-Melatonin, pubmed-meshheading:11435758-Mesocricetus, pubmed-meshheading:11435758-Phodopus, pubmed-meshheading:11435758-Photoperiod, pubmed-meshheading:11435758-Pineal Gland, pubmed-meshheading:11435758-Pituitary Gland, pubmed-meshheading:11435758-Radioligand Assay, pubmed-meshheading:11435758-Receptors, Cell Surface, pubmed-meshheading:11435758-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:11435758-Receptors, Melatonin, pubmed-meshheading:11435758-Suprachiasmatic Nucleus
pubmed:year
2001
pubmed:articleTitle
The circadian clock, light/dark cycle and melatonin are differentially involved in the expression of daily and photoperiodic variations in mt(1) melatonin receptors in the Siberian and Syrian hamsters.
pubmed:affiliation
Neurobiologie des Fonctions Rythmiques et Saisonnières, CNRS-UMR 7518, Université Louis-Pasteur, 12, rue de l'Université, F-67000 Strasbourg, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't