title: Prostaglandin-endoperoxide H synthase-2 expression and activity increases with term labor in human chorion.
abstract: We investigated the changes in prostaglandin-endoperoxide H synthase (PGHS) specific activity and the levels and distribution of PGHS-1 and PGHS-2 mRNA in chorion collected at term before the onset of labor (CS) and after term labor and delivery (SL). PGHS specific activity and PGHS-2 mRNA abundance were higher in chorion collected after SL compared with that obtained at CS (P < 0.001); there was no difference in the levels of PGHS-1 mRNA between CS and SI, tissues. The increase in PGHS specific activity at SL was significantly correlated with PGHS-2 mRNA expression (P < 0.05) but not with PGHS-1 mRNA levels. In situ hybridization indicated that the pervasiveness of staining for PGHS-1 mRNA throughout full-thickness membranes did not change with labor onset; however, a greater number of cells expressed PGHS-2 in SL tissues. Our results demonstrate a selective increase in PGHS-2 expression and activity in chorion trophoblasts and mesenchymal cells with term labor onset. These observations are similar to those concerning amnion and imply that a concerted mechanism may exist in the fetal membranes to induce PGHS-2 expression at labor.
authors.affiliation: Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: J E
authors.initials: JE
authors.lastname: Mijovic
authors.forename: T
authors.initials: T
authors.lastname: Zakar
authors.forename: T K
authors.initials: TK
authors.lastname: Nairn
authors.forename: D M
authors.initials: DM
authors.lastname: Olson
mesh_terms: D002823:Chorion / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D007743:Labor, Obstetric / Q000378:metabolism*; D049590:Postpartum Period / Q000378:metabolism; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D012333:RNA, Messenger; D011451:Prostaglandin-Endoperoxide Synthases