title: Effects of sustained hypoxaemia with 72 hours recovery on 11beta-hydroxysteroid dehydrogenase types 1 and 2 gene expression in near-term fetal sheep.
abstract: The study examined the effects of 8 h sustained hypoxaemia, with 72 h recovery, on the expression of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) types 1 and 2 in near-term fetal sheep. Placental tissue and fetal liver and kidney were collected at Days 135-138 gestation 72 h after 8 h sustained hypoxaemia induced by lowering maternal inspired oxygen with (n = 9) and without (n = 6) metabolic acidosis or after 8 h normoxia (n = 6). In hypoxic fetuses with metabolic acidosis, a significant increase in the level of 11beta-HSD2 mRNA in the kidney compared with controls was correlated significantly with degree of associated fetal acidaemia, but there were no corresponding increases in the tissue level of 11beta-HSD2 activity. Hence, a time lag may exist between the mRNA and activity. Alternatively, the translation of 11beta-HSD2 mRNA may be inhibited. In contrast, levels of 11beta-HSD1 mRNA in the placenta and fetal liver were unchanged 72 h after sustained hypoxaemia. These results indicate that sustained fetal hypoxaemia with metabolic acidosis selectively up-regulates 11beta-HSD2 mRNA expression in the near-term fetal sheep kidney. This may be a re-bound effect at 72 h following an initial down-regulation as observed in a previous study.
authors.affiliation: The Lawson Research Institute, St Joseph's Hospital, Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Asano
authors.forename: K
authors.initials: K
authors.lastname: Shearman
authors.forename: A
authors.initials: A
authors.lastname: Darnel
authors.forename: B S
authors.initials: BS
authors.lastname: Richardson
authors.forename: K
authors.initials: K
authors.lastname: Yang
mesh_terms: D042842:11-beta-Hydroxysteroid Dehydrogenases; D000818:Animals; D001784:Blood Gas Analysis; D005333:Fetus / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006863:Hydrogen-Ion Concentration; D006913:Hydroxysteroid Dehydrogenases / Q000235:genetics*; D000860:Hypoxia / Q000201:enzymology*; D007668:Kidney / Q000196:embryology / Q000201:enzymology; D012333:RNA, Messenger / Q000378:metabolism; D012756:Sheep
chemical_list: D012333:RNA, Messenger; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases