Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-9-17
pubmed:abstractText
Pituitary-specific transcription factor Pit-1 regulates growth hormone and prolactin gene expression in the pituitary. Recently, Pit-1 was shown to be locally synthesized in the rat placenta and is involved in the regulation of rat placental lactogen (PL) gene expression. Pit-1 has three different splicing variants. They are well known as being biologically active. In the present study, we found that Pit-1 beta is also synthesized in the rat placenta and we tried to examine the effects of dopamine and estrogen on the regulation of Pit-1 alpha, beta and PL-II genes expression using the reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot hybridization. A dopamine receptor agonist, bromocriptine, significantly decreased placental Pit-1 alpha, beta, and PL-II mRNA levels. To examine the effect of estrogen on the gene expression of Pit-1 beta, pregnant female rats were ovariectomized (OVX) and injected daily with 17 beta-estradiol. OVX markedly lowered the amount of Pit-1 beta mRNA. Estrogen injection recovered the OVX-induced inhibition of Pit-1 beta mRNA level. Finally, we investigated the site-specific transcription of Pit-1 alpha and beta mRNA in the labyrinth zone and junctional zone of the placental in 15 and 20 days of gestation. The main site of Pit-1 alpha and beta synthesis was shifted from the junctional zone to the labyrinth zone from 15 to 20 days of gestation. Together, these data presume that Pit-1 beta may play a more important role in the placenta than in the pituitary and that Pit-1 may be involved in the regulation of the PL and prolactin-like peptide by estrogen and dopamine in the rat placenta.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1016-8478
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
205-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Effects of dopamine and estrogen on the regulation of Pit-1 alpha, Pit-1 beta, and PL-II gene expression in the rat placenta.
pubmed:affiliation
Department of Biology, College of Natural Sciences, Inje University, Kimhae, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't