Linked Life Data

15046865

Source:http://linkedlifedata.com/resource/pubmed/id/15046865

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2004-3-29
pubmed:abstractText
The nocturnal biosynthesis of melatonin in the rat pineal depends on strongly enhanced expression of the enzyme N-acetyltransferase [arylalkylamine N-acetyltransferase (AA-NAT); EC 2.3.1.87]. AA-NAT transcription is stimulated during darkness by adrenergic inputs to the pineal from the suprachiasmatic nucleus (SCN). Nocturnal activation of the AA-NAT promotor following stimulation of pinealocyte adrenoceptors involves cAMP-dependent stimulation of protein kinase A (PKA). The nocturnal rise in AA-NAT depends on the lighting conditions. As compared with light/dark (LD) 12:12, the delay between dark onset and the nocturnal rise in AA-NAT is shortened under long photoperiods and prolonged under short photoperiods. Here, we report that the rapidity of nocturnal AA-NAT induction depends on cAMP inducibility of the gene. Accordingly, cAMP produces a strong AA-NAT response in pineals obtained from rats housed under long photoperiods and a weak AA-NAT response under short photoperiods. Changes in AA-NAT inducibility are fully developed not earlier than after seven cycles. This observation suggests that long-term changes in the photoperiod are necessary to achieve full adjustment of cAMP inducibility of the gene. A direct relationship was found between cAMP-dependent AA-NAT inducibility and the pineal protein kinase A (PKA) activity. As compared to LD 12:12, PKA activity was increased under LD 20:4 and attenuated under LD 4:20. On the basis of the present findings, we suggest that the photoperiod determines the effectiveness of nocturnal AA-NAT induction by long-term modulation of the intrapineal pathway that transmits the cAMP signal to the AA-NAT gene.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0169-328X
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
123
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-55
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:15046865-Adrenergic beta-Agonists, pubmed-meshheading:15046865-Animals, pubmed-meshheading:15046865-Arylamine N-Acetyltransferase, pubmed-meshheading:15046865-Circadian Rhythm, pubmed-meshheading:15046865-Cyclic AMP, pubmed-meshheading:15046865-Cyclic AMP-Dependent Protein Kinases, pubmed-meshheading:15046865-Darkness, pubmed-meshheading:15046865-Enzyme Induction, pubmed-meshheading:15046865-Gene Expression Regulation, Enzymologic, pubmed-meshheading:15046865-Male, pubmed-meshheading:15046865-Melatonin, pubmed-meshheading:15046865-Norepinephrine, pubmed-meshheading:15046865-Organ Culture Techniques, pubmed-meshheading:15046865-Photic Stimulation, pubmed-meshheading:15046865-Photoperiod, pubmed-meshheading:15046865-Pineal Gland, pubmed-meshheading:15046865-Rats, pubmed-meshheading:15046865-Rats, Sprague-Dawley, pubmed-meshheading:15046865-Receptors, Adrenergic, beta, pubmed-meshheading:15046865-Signal Transduction
pubmed:year
2004
pubmed:articleTitle
Rat pineal arylalkylamine-N-acetyltransferase: cyclic AMP inducibility of its gene depends on prior entrained photoperiod.
pubmed:affiliation
Department of Anatomy, Johannes Gutenberg University, Saarstrasse 19-21, D-55099 Mainz, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't