Linked Life Data

1786297

Source:http://linkedlifedata.com/resource/pubmed/id/1786297

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-3-20
pubmed:abstractText
Prostaglandin H synthase (PGHS) activity within intrauterine tissues is considered to catalyze a critical step in prostaglandin (PG) biosynthesis at parturition. In sheep, the placenta is a major site of PG production throughout pregnancy, but little information is available concerning the cells that are responsible. Therefore we determined the distribution of immunoreactive (IR-) PGHS in ovine placental tissue obtained at different times of pregnancy using immunohistochemical techniques. In placentomes from early pregnancy (Days 30-54), IR-PGHS was present in maternal epithelial syncytium, but was not detectable in trophoblast cells. Between Day 54 and Day 100, the number of cells that stained positive for PGHS declined in the maternal epithelial layer in the body of the placenta, but IR-PGHS was present in maternal epithelial cells overlying the vascular cones of the placental hemophagous zone. It was also present in the chorionic fibroblasts, but remained undetectable from all classes of trophoblast cells. IR-PGHS was first detectable in the trophoblastic epithelium by Day 114. Between Day 119 and term the trophoblast mononuclear epithelial cells were intensely immunopositive for PGHS, although immunonegative binucleate cells were present. The maternal epithelium was immunonegative except during the last 7-10 days of pregnancy when PGHS immunostaining appeared in both basal and apical regions of the placenta. Thus, the cellular localization of IR-PGHS changes during ovine pregnancy, from predominantly maternal during the first half of gestation to undetectable and then to predominantly trophoblastic between Day 114 and term, suggesting a gestation-dependent change in sites of PG production during ovine pregnancy. Appearance of IR-PGHS in the trophoblast precedes activation of the fetal hypothalamic-pituitary-adrenal axis, generally considered to provide the trigger to the onset of parturition in sheep, and would therefore appear to be regulated through alternative pathways or mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
322-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Immunohistochemical localization of prostaglandin H synthase in the sheep placenta from early pregnancy to term.
pubmed:affiliation
MRC Group in Fetal and Neonatal Health and Development, Lawson Research Institute, London, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't