title: Gestational- and labour-associated changes in the relative abundance of prostaglandin G/H synthase-1 and -2 mRNA in ovine placenta.
abstract: The aim of this study was to establish the gestational- and labour-associated variation in the relative abundance of prostaglandin synthase-1 (PGHS-1) and prostaglandin synthase-2 (PGHS-2) mRNA in ovine placenta (cotyledons). Cotyledons were collected from non-labouring ewes at 40-145 days of gestation (n = 25) and from ewes in active labour (145-147 days, n = 5). The relative abundance of PGHS-1 and PGHS-2 mRNA transcripts was determined by Northern blot analysis and laser densitometry, using a 2.3 kb sheep and a 1.2 kb mouse cDNA probe respectively. Data were expressed as a ratio of PGHS transcript hybridization/18S rRNA hybridization. During pregnancy, the relative abundance of PGHS-2 mRNA increased sevenfold, from 0.19 +/- 0.04 at 40-85 days (n = 5) to 1.39 +/- 0.05 at 140-145 days (n = 4) (P < 0.01). PGHS-1 mRNA relative abundance did not change significantly (P > 0.05) during gestation. Neither PGHS-1 nor PGHS-2 mRNA relative abundance changed significantly in association with labour onset at term (n = 5) when compared with the relative abundance observed at 140-145 days (n = 4) (P > 0.05). The data obtained in this study are consistent with the hypothesis that PGHS-1 is constitutively expressed in ovine placenta during pregnancy and at the time of labour, and that PGHS-2 is induced during the second half of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, Monash University, Clayton, Victoria, Australia.
authors.forename: G E
authors.initials: GE
authors.lastname: Rice
authors.forename: K A
authors.initials: KA
authors.lastname: Freed
authors.forename: M A
authors.initials: MA
authors.lastname: Aitken
authors.forename: R A
authors.initials: RA
authors.lastname: Jacobs
mesh_terms: D000818:Animals; D004247:DNA / Q000235:genetics; D004790:Enzyme Induction; D005260:Female; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D007743:Labor, Obstetric / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis*; D012756:Sheep / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity; D014714:Vertebrates / Q000235:genetics
chemical_list: D007527:Isoenzymes; D012333:RNA, Messenger; D004247:DNA; D011451:Prostaglandin-Endoperoxide Synthases