title: The effects of dexamethasone treatment in early gestation on hypothalamic-pituitary-adrenal responses and gene expression at 7 months of postnatal age in sheep.
abstract: We determined the effects of prenatal dexamethasone administration in early gestation on development of the hypothalamic-pituitary-adrenal (HPA) axis up to 7 months of postnatal age with measurements of hormone levels and gene expression. Plasma adrenocorticotropic hormone and cortisol levels after corticotropin-releasing hormone (CRH)/arginine vasopressin challenge were lower in treatment females than in control females and treatment males. Calculation of cortisol to adrenocorticotropic hormone ratios indicated however that the adrenals of treatment females were more responsive to adrenocorticotropic hormone than control females or treatment males. Effects of treatment and sex dependence at 7 months of age were observed in levels of hypothalamic CRH messenger RNA (mRNA), hypothalamic arginine vasopressin mRNA, pituitary proopiomelanocortin mRNA, pituitary prohormone convertase 1 and prohormone convertase 2, glucocorticoid receptor and mineralocorticoid receptor in the hypothalamus and hippocampus, adrenal adrenocorticotropic hormone receptor, steroidogenic acute regulatory, 3β hydroxysteroid dehydrogenase, and 11β hydroxysteroid dehydrogenase type 2 mRNA. The results indicate that exposure to glucocorticoids in early pregnancy produces persisting and sex-dependent effects on the hypothalamic-pituitary-adrenal axis at 7 months of age.
authors.affiliation: School of Women's and Infants' Health, The University of Western Australia, Western Australia, Australia. shaofu.li@uwa.edu.au
authors.forename: Shaofu
authors.initials: S
authors.lastname: Li
authors.forename: Ilias
authors.initials: I
authors.lastname: Nitsos
authors.forename: Graeme R
authors.initials: GR
authors.lastname: Polglase
authors.forename: Thorsten
authors.initials: T
authors.lastname: Braun
authors.forename: Timothy J M
authors.initials: TJ
authors.lastname: Moss
authors.forename: John P
authors.initials: JP
authors.lastname: Newnham
authors.forename: John R G
authors.initials: JR
authors.lastname: Challis
mesh_terms: D000818:Animals; D017849:Animals, Inbred Strains; D003907:Dexamethasone / Q000009:adverse effects*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D005938:Glucocorticoids / Q000009:adverse effects*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008297:Male; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D034561:Sheep, Domestic
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone