Regulation of membrane-associated prostaglandin E2 synthase 1 in pregnant sheep intrauterine tissues by glucocorticoid and estradiol.

Journal Article (Journal Article)

This study was designed to determine the regulatory effect of glucocorticoid and estradiol on expression of ovine intrauterine membrane-associated prostaglandin E(2) synthase 1 (mPTGES1) in late gestation and at labor. For gestational and labor groups, 16 pregnant ewes from 95-147 d gestational age (dGA) and four pregnant ewes at spontaneous term labor were used. The fetal glucocorticoid group, 14 pregnant ewes at 123-125 dGA with fetuses, was divided into the following groups: after sham adrenalectomy (n = 5), adrenalectomy (n = 4), and adrenalectomy with fetal cortisol replacement to late gestation levels (n = 5). For the maternal glucocorticoid group, nine pregnant ewes were treated with saline (n = 4) and three courses of maternal dexamethasone (n = 5). For the estradiol group, 10 pregnant ewes at 119-121 dGA were treated with sesame oil (n = 5) or estradiol (n = 5) to produce labor levels of estradiol in maternal plasma. Endometrial, myometrial, and placental mRNA and proteins were analyzed by Northern and Western blot and immunocytochemistry for mPTGES1. Data were analyzed by Student's t test and ANOVA. There was a significant increase of placental mPTGES1 in late gestation. Glucocorticoids, given to the mother or fetus, significantly stimulated mPTGES1 in placenta. mPTGES1 was elevated only in the endometrium during spontaneous term labor and after estradiol treatment. The mPTGES1 was localized in the myometrial smooth muscle cells, endometrial stromal cells, and placental trophoblast cells. Our study suggested that increased expression of placental mPTGES1 throughout late gestation might result from the increased fetal and maternal circulating glucocorticoids, whereas elevated maternal plasma estradiol concentration might be responsible for the induced mPTGES1 expression in the endometrium during labor.

Full Text

Duke Authors

Cited Authors

  • Zhang, Q; Collins, V; Chakrabarty, K; Wolf, RF; Unno, N; Howe, D; Rose, JC; Wu, WX

Published Date

  • August 2006

Published In

Volume / Issue

  • 147 / 8

Start / End Page

  • 3719 - 3726

PubMed ID

  • 16690805

Electronic International Standard Serial Number (EISSN)

  • 1945-7170

International Standard Serial Number (ISSN)

  • 0013-7227

Digital Object Identifier (DOI)

  • 10.1210/en.2006-0293


  • eng