title: Differential effects of placental restriction on IGF-II, ACTH receptor and steroidogenic enzyme mRNA levels in the foetal sheep adrenal.
abstract: We have investigated the effects of restriction of placental growth on foetal adrenal growth and adrenal expression of mRNAs for Insulin-like Growth Factor II (IGF-II), the IGF binding protein IGFBP-2, Steroidogenic Factor 1 (SF-1) and adrenocorticotrophic hormone (ACTH) receptor (ACTH-R) and the steroidogenic cytochrome P-450 enzymes: cholesterol side chain cleavage (CYP11A1), 17alpha-hydroxylase (CYP17) and 21-hydroxylase (CYP21A1); and 3beta-hydroxysteroid dehydrogenase/Delta5Delta4 isomerase (3betaHSD). Endometrial caruncles were removed from non-pregnant ewes before mating (placental restriction group; PR). The total adrenal: foetal weight ratio was higher in PR (n=6 foetuses) than in control foetuses (n=6 foetuses). There was no difference in plasma ACTH concentrations between the PR and control foetuses between 130 and 140 days gestation. Adrenal IGF-II mRNA levels were lower (P<0.05) in the PR group, however, adrenal IGFBP-2 mRNA levels were not different between the PR and control groups. Adrenal ACTH-R mRNA levels were also lower whilst CYP11A1 mRNA levels were increased (P<0.005) in the PR group. We conclude that foetal adrenal growth and steroidogenesis are stimulated as a consequence of foetal growth restriction and that factors other than ACTH are important in foetal adrenal activation during chronic, sustained hypoxaemia.
authors.affiliation: Department of Physiology, The University of Adelaide, Adelaide 5005, SA, Australia.
authors.forename: J T
authors.initials: JT
authors.lastname: Ross
authors.forename: I D
authors.initials: ID
authors.lastname: Phillips
authors.forename: G
authors.initials: G
authors.lastname: Simonetta
authors.forename: J A
authors.initials: JA
authors.lastname: Owens
authors.forename: J S
authors.initials: JS
authors.lastname: Robinson
authors.forename: I C
authors.initials: IC
authors.lastname: McMillen
mesh_terms: D000311:Adrenal Glands / Q000196:embryology* / Q000378:metabolism; D000818:Animals; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D005260:Female; D005333:Fetus / Q000502:physiology; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D009097:Multienzyme Complexes / Q000235:genetics*; D009929:Organ Size; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy; D011375:Progesterone Reductase / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018043:Receptors, Corticotropin / Q000235:genetics*; D012016:Reference Values; D012756:Sheep; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics; D013255:Steroid 21-Hydroxylase / Q000235:genetics; D013251:Steroid Isomerases / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: C021425:3 beta-hydroxysteroid oxidoreductase-delta(5) 3-ketosteroid isomerase; D009097:Multienzyme Complexes; D012333:RNA, Messenger; D018043:Receptors, Corticotropin; D007335:Insulin-Like Growth Factor II; D003577:Cytochrome P-450 Enzyme System; D011375:Progesterone Reductase; D013255:Steroid 21-Hydroxylase; D013254:Steroid 17-alpha-Hydroxylase; D002786:Cholesterol Side-Chain Cleavage Enzyme; D013251:Steroid Isomerases