Linked Life Data

18063680

Source:http://linkedlifedata.com/resource/pubmed/id/18063680

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-2-22
pubmed:databankReference
pubmed:abstractText
We recently identified a novel hypothalamic neuropeptide stimulating GH release in bullfrogs and termed it frog GH-releasing peptide (fGRP). The fGRP precursor encodes fGRP and its related peptides (fGRP-RP-1, -RP-2, and -RP-3), and fGRP-RP-2 also stimulates GH and prolactin (PRL) release. Cell bodies and terminals containing these neuropeptides are localized in the suprachiasmatic nucleus (SCN) and median eminence, respectively. To understand the physiological role of fGRP and fGRP-RP-2, we investigated the mechanisms that regulate the expression of these neuropeptides. This study shows that melatonin induces the expression of fGRP and fGRP-RPs in bullfrogs. Orbital enucleation combined with pinealectomy (Ex plus Px) decreased the expression of fGRP precursor mRNA and content of mature fGRP and fGRP-RPs in the diencephalon including the SCN and median eminence. Conversely, melatonin administration to Ex plus Px bullfrogs increased dose-dependently their expressions. The expression of fGRP precursor mRNA was photoperiodically controlled and increased under short-day photoperiods, when the nocturnal duration of melatonin secretion increases. To clarify the mode of melatonin action on the induction of fGRP and fGRP-RPs, we further demonstrated the expression of Mel(1b), a melatonin receptor subtype, in SCN neurons expressing fGRP precursor mRNA. Finally, we investigated circulating GH and PRL levels after melatonin manipulation because fGRP and fGRP-RP-2 stimulate the release of GH and GH/PRL, respectively. Ex plus Px decreased plasma GH and PRL concentrations, whereas melatonin administration increased these hormone levels. These results suggest that melatonin induces the expression of fGRP and fGRP-RP-2, thus stimulating the release of GH and PRL in bullfrogs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
149
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
962-70
pubmed:meshHeading
pubmed-meshheading:18063680-Amino Acid Sequence, pubmed-meshheading:18063680-Animals, pubmed-meshheading:18063680-Base Sequence, pubmed-meshheading:18063680-Dose-Response Relationship, Drug, pubmed-meshheading:18063680-Eye Enucleation, pubmed-meshheading:18063680-Gene Expression Regulation, pubmed-meshheading:18063680-Growth Hormone, pubmed-meshheading:18063680-Growth Hormone-Releasing Hormone, pubmed-meshheading:18063680-Hypothalamus, pubmed-meshheading:18063680-Male, pubmed-meshheading:18063680-Melatonin, pubmed-meshheading:18063680-Molecular Sequence Data, pubmed-meshheading:18063680-Oligopeptides, pubmed-meshheading:18063680-Photoperiod, pubmed-meshheading:18063680-Pineal Gland, pubmed-meshheading:18063680-Prolactin, pubmed-meshheading:18063680-RNA, Messenger, pubmed-meshheading:18063680-Rana catesbeiana
pubmed:year
2008
pubmed:articleTitle
Melatonin stimulates the release of growth hormone and prolactin by a possible induction of the expression of frog growth hormone-releasing peptide and its related peptide-2 in the amphibian hypothalamus.
pubmed:affiliation
Laboratory of Integrative Brain Sciences, Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, 1-6-1 Nishi-Waseda, Shinjuku-ku, Tokyo 169-8050, Japan. .
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't