title: Gestation-related and betamethasone-induced changes in 11beta-hydroxysteroid dehydrogenase types 1 and 2 in the baboon placenta.
abstract: OBJECTIVE
  We determined developmental and labor-related changes in 11beta-hydroxysteroid (HSD) 1 and 2 expression in baboon placentas during the final third of gestation and labor. We examined whether maternal glucocorticoid administration alters placental 11beta-HSD 2 expression.
  
  
  METHODS
  Maternal and fetal plasma cortisol concentrations were measured in five animals. Types 1 and 2 11beta-HSD messenger RNA (mRNA) and protein in placentas obtained at 121 to 185 days' gestation (dGA, term approximately 185 dGA, n = 16), during labor between 141 and 193 dGA (n = 8), and after maternal administration of four doses of 87.5 microg/kg betamethasone (n = 5) at 12-hour intervals at 121 to 135 dGA were analyzed by Northern and Western blot.
  
  
  RESULTS
  Cortisol levels were higher in maternal plasma than fetal (4-fold, P <.mob031). Placental 11beta-HSD 2 mRNA and protein decreased after 0.9 gestation (P <.001). 11beta-HSD 1 mRNA remained unchanged. There was no effect of labor on placental 11beta-HSD 1 and 2 mRNA and protein levels. Maternal betamethasone administration dramatically increased (P <.05) 11beta-HSD 2 mRNA as well as protein without effect on 11beta-HSD 1 mRNA and protein expression.
  
  
  CONCLUSIONS
  The late-gestation baboon maternal plasma cortisol concentration is four times the fetal plasma concentration. Decreased placental 11beta-HSD 2 may enhance maternal cortisol passage to the fetus at the end of gestation, thereby contributing to cortisol-mediated changes within the placenta and cortisol in fetal plasma at this stage of fetal development. The positive effect of betamethasone on placental 11beta-HSD 2 induction further suggests an ability of the placenta to regulate glucocorticoid transfer in the presence of elevated maternal glucocorticoid.
authors.affiliation: Laboratory of Pregnancy and Newborn Research, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Xiao Hong
authors.initials: XH
authors.lastname: Ma
authors.forename: Wen Xuan
authors.initials: WX
authors.lastname: Wu
authors.forename: Peter W
authors.initials: PW
authors.lastname: Nathanielsz
mesh_terms: D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D000818:Animals; D001623:Betamethasone / Q000494:pharmacology*; D015152:Blotting, Northern; D015153:Blotting, Western; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D005938:Glucocorticoids / Q000494:pharmacology*; D006854:Hydrocortisone / Q000097:blood; D006913:Hydroxysteroid Dehydrogenases / Q000032:analysis* / Q000235:genetics; D007743:Labor, Obstetric / Q000502:physiology; D010215:Papio; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D005938:Glucocorticoids; D012333:RNA, Messenger; D001623:Betamethasone; D006913:Hydroxysteroid Dehydrogenases; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D006854:Hydrocortisone