Linked Life Data

1699155

Source:http://linkedlifedata.com/resource/pubmed/id/1699155

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-11-14
pubmed:abstractText
In the rat pineal gland, the activity of serotonin N-acetyltransferase (NAT) and the concentration of melatonin are normally high at night; conversely, the concentration of serotonin (5-HT), the precursor of melatonin, is low. Since tryptophan administration increases the concentration of pineal 5-HT at night, we examined its effect of melatonin production. Nighttime tryptophan loading led to substantial increases in pineal 5-hydroxytryptophan, 5-hydroxyindole acetic acid (5-HIAA), and 5-HT but a highly significant reduction in NAT activity in comparison to saline-injected controls. In contrast to other measured indoles, melatonin levels also were significantly diminished by tryptophan loading. Nocturnally high pineal norepinephrine levels were unaltered by tryptophan administration. The idea that high concentrations of 5-HT could lead to substrate inhibition of NAT activity was not supported by kinetic analysis of control NAT levels versus tryptophan-inhibited NAT activity under varied substrate concentrations. Hypotheses to explain these results include the possibility that tryptophan inhibition of melatonin synthesis is mediated by the release of 5-HT from the pinealocyte and its subsequent autocrine action on melatonin production.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0028-3835
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
291-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Tryptophan administration inhibits nocturnal N-acetyltransferase activity and melatonin content in the rat pineal gland. Evidence that serotonin modulates melatonin production via a receptor-mediated mechanism.
pubmed:affiliation
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't