Document Detail

Mouse placental prostaglandins are associated with uterine activation and the timing of birth.
MedLine Citation:
PMID:  12533422     Owner:  NLM     Status:  MEDLINE    
We explored a potential mechanism linking placental prostaglandins (PGs) with a fall in plasma progesterone and increased expression of uterine activation proteins in the mouse. PG endoperoxide H synthase 2 (PGHS-2) mRNA expression increased in placenta in late gestation in association with an 8-fold increase in PGF(2alpha) concentration, reaching a peak on Gestational Day (GD) 18. This peak coincided with the final descent in plasma progesterone and birth on GD 19.3 +/- 0.2. Implantation of a progesterone-releasing pellet in intact pregnant dams on GD 16 delayed birth at term until GD 20.9 +/- 0.4 and inhibited the GD 18 increase in placental PGF(2alpha) levels in conjunction with a delayed fall in plasma progesterone that reached its lowest level 1 day after term birth. The mRNA levels of uterine activation proteins, connexin-43 (CX-43), oxytocin receptor, PGF(2alpha) receptor (FP), and PGHS-2, and the concentration of uterine PGF(2alpha) all increased at normal term birth. At progesterone-delayed term birth on GD 19.3, even though tissue PGF(2alpha) concentrations were at the same high levels observed at normal term birth, CX-43 and FP mRNA levels were lower than those at normal term birth, thereby possibly contributing to the delay of birth. These data are consistent with the hypotheses that fetal placental PGs affect the timing of birth by hastening luteolysis, that uterine activation initiates labor, and that birth may be delayed by blocking or decreasing the expression of two of the uterine activation proteins.
Jocelynn L Cook; Maria C Shallow; Dean B Zaragoza; Kimberley I Anderson; David M Olson
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biology of reproduction     Volume:  68     ISSN:  0006-3363     ISO Abbreviation:  Biol. Reprod.     Publication Date:  2003 Feb 
Date Detail:
Created Date:  2003-01-20     Completed Date:  2003-08-01     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0207224     Medline TA:  Biol Reprod     Country:  United States    
Other Details:
Languages:  eng     Pagination:  579-87     Citation Subset:  IM    
Department of Obstetrics and Gynaecology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2.
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MeSH Terms
Cyclooxygenase 2
Dinoprost / metabolism*
Dinoprostone / metabolism*
Extraembryonic Membranes / metabolism
Isoenzymes / genetics,  metabolism*
Mice, Inbred C57BL
Osmolar Concentration
Placenta / metabolism*
Progesterone / blood
Prostaglandin-Endoperoxide Synthases / genetics,  metabolism*
RNA, Messenger / metabolism
Time Factors
Uterus / physiology*
Reg. No./Substance:
0/Isoenzymes; 0/RNA, Messenger; 363-24-6/Dinoprostone; 551-11-1/Dinoprost; 57-83-0/Progesterone; EC 2; EC Synthases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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