This Article Full Text Full Text (PDF) All Versions of this Article: 137/3/537    most recent REP-08-0294v1 Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gillio-Meina, C. Articles by Kennedy, T. G Search for Related Content PubMed PubMed Citation Articles by Gillio-Meina, C. Articles by Kennedy, T. G

Expression patterns and role of prostaglandin-endoperoxide synthases, prostaglandin E synthases, prostacyclin synthase, prostacyclin receptor, peroxisome proliferator-activated receptor delta and retinoid x receptor alpha in rat endometrium during artificially-induced decidualization

Departments of¹ , Physiology and Pharmacology² Obstetrics and Gynecology, The University of Western Ontario, London, Ontario, Canada N6A 5C1

Correspondence should be addressed to T G Kennedy; Email: tom.kennedy{at}schulich.uwo.ca

To determine if changes in endometrial expression of the enzymes and receptors involved in prostaglandin (PG) synthesis and action might provide insights into the PGs involved in the initiation of decidualization, ovariectomized steroid-treated rats at the equivalent of day 5 of pseudopregnancy were given a deciduogenic stimulus and killed at various times up to 32 h thereafter. The expression of PG-endoperoxide synthases (PTGS1 and PTGS2), microsomal PGE synthases (PTGES and PTGES2), cytosolic PGE synthase (PTGES3), prostacyclin synthase (PTGIS), prostacyclin receptor, peroxisome proliferator-activated receptor (PPARD) and retinoid x receptor (RXRA) in endometrium was assessed by semiquantitative RT-PCR, western blot analyses and immunohistochemistry. In addition, to determine which PG is involved in mediating decidualization, we compared the ability of PGE₂, stable analogues of PGI₂, L165041 (an agonist of PPARD), and docasahexanoic acid (an agonist of RXRA) to increase endometrial vascular permeability (EVP, an early event in decidualization), and decidualization when infused into the uterine horns of rats sensitized for the decidual cell reaction (DCR). EVP was assessed by uterine concentrations of Evans blue 10 h after initiation of infusions. DCR was assessed by the uterine mass 5 days after the initiation of the infusions. Because enzymes associated with the synthesis of PGE₂, including PTGS2, are up-regulated in response to a deciduogenic stimulus and because PGE₂ was more effective than the PGI₂ analogues and PPARD and RXRA agonists in increasing EVP and inducing decidualization, we suggest that PGE₂ is most likely the PG involved in the initiation of decidualization in the rat.