Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1993-2-25
pubmed:abstractText
Maternal recognition of pregnancy in sheep, cattle and goats involves physiological mechanisms that result in protection of corpora lutea from luteolysis by modification or inhibition of uterine production of luteolytic pulses of prostaglandin (PG) F-2 alpha. Ovine, bovine and caprine luteal cells release oxytocin in a pulsatile manner during late dioestrus. Oxytocin then binds to its endometrial receptors and initiates luteolytic pulses of PGF-2 alpha. Ovine, bovine and caprine trophoblast protein-1 (oTP-1, bTP-1 and cTP-1) are secreted by the trophectoderm of conceptuses between Days 10 and 21-24 of pregnancy. These antiluteolytic proteins (oTP-1 and bTP-1) are primarily responsible for inhibiting uterine production of luteolytic amounts of PGF-2 alpha. During early pregnancy, the numbers of endometrial receptors for oxytocin are significantly lower in ewes and cows, and stimulatory effects of exogenous oxytocin on uterine production of PGF-2 alpha are correspondingly reduced or absent for ewes, cows and goats. Exogenous oestrogens can, through a uterine-dependent mechanism, stimulate synthesis of endometrial receptors for oxytocin and uterine production of PGF-2 alpha; an effect which is significantly attenuated during early pregnancy. These results suggest that oTP-1, bTP-1 and possibly cTP-1 exert their antiluteolytic effect(s) by: (1) inhibiting effects of oestrogen and/or progesterone necessary for synthesis of endometrial receptors for oxytocin; (2) inhibiting endometrial synthesis and/or recycling of oxytocin receptors directly; or (3) inducing the endometrium to synthesize an inhibitor of an enzyme(s) necessary for synthesis of PGF-2 alpha.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0449-3087
pubmed:author
pubmed:issnType
Print
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-47
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Physiological mechanisms of pregnancy recognition in ruminants.
pubmed:affiliation
Animal Science Department, University of Florida, Gainesville 32611-0691.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Review, Research Support, Non-U.S. Gov't