Linked Life Data

12960030

Source:http://linkedlifedata.com/resource/pubmed/id/12960030

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2003-9-22
pubmed:abstractText
In Teleost fish, development, growth, and reproduction are influenced by the daily and seasonal variations of photoperiod and temperature. Early in vivo studies indicated the pineal gland mediates the effects of these external factors, most probably through the rhythmic production of melatonin. The present investigation was aimed at determining whether melatonin acts directly on the pituitary to control GH and prolactin (PRL) secretion in rainbow trout. We show that 2-[125I]-iodomelatonin, a melatonin analog, binds selectively to membrane preparations and tissue sections from trout pituitaries. The affinity was within the range of that found for the binding to brain microsomal preparations, but the number of binding sites was 20-fold less than in the brain. In culture, melatonin inhibited pituitary cAMP accumulation induced by forskolin, the adenyl cyclase stimulator. Forskolin also induced an increase in GH release, which was reduced in the presence of picomolar concentrations of melatonin. At higher concentrations, the effects of melatonin became stimulatory. In the absence of forskolin, melatonin induced a dose-dependent increase in GH release, and a dose-dependent decrease in PRL release. Melatonin effects were abolished upon addition of luzindole, a melatonin antagonist. Our results provide the first evidence that melatonin modulates GH and PRL secretion in Teleost fish pituitary. Melatonin effects on GH have never been reported in any vertebrate before. The effects result from a direct action of melatonin on pituitary cells. The complexity of the observed responses suggests several types of melatonin receptors might be involved.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4648-58
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Melatonin modulates secretion of growth hormone and prolactin by trout pituitary glands and cells in culture.
pubmed:affiliation
Laboratoire Arago, Unité Mixte de Recherche 7628, Centre National de la Recherche Scientifique/Université P et M Curie, BP 44, F-66651 Banyuls sur Mer, France. falcon@obs-banyuls.fr.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't