title: Regulation and function of the fetal adrenal gland in sheep.
abstract: It is now known that in some species (sheep, cow, pig, llama) the fetal adrenal cortex is capable of secreting cortisol both early and late in gestation, but not during some, variable, intermediate time period. In the sheep the fetal adrenal can secrete cortisol, and respond quickly to ACTH, both between 40-90 days of gestation, and from 120-150 days (term), but not between 90-120 days. The inability to secrete cortisol in this 'off' period is due to lack of adequate pituitary ACTH at this time to maintain expression of P-450(17 alpha and P-450scc. Recent experiments demonstrate that the fetal pituitary does secrete adequate amounts of ACTH to keep these genes expressed, in the 40-90 day period. The question now becomes, therefore, what regulates the triphasic secretion pattern of ACTH during fetal sheep development.
authors.affiliation: Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: E M
authors.initials: EM
authors.lastname: Wintour
authors.forename: R
authors.initials: R
authors.lastname: Crawford
authors.forename: A
authors.initials: A
authors.lastname: McFarlane
authors.forename: K
authors.initials: K
authors.lastname: Moritz
authors.forename: K
authors.initials: K
authors.lastname: Tangalakis
mesh_terms: D000311:Adrenal Glands / Q000196:embryology / Q000502:physiology*; D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis / Q000378:metabolism*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System; D003907:Dexamethasone / Q000378:metabolism / Q000494:pharmacology; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D005865:Gestational Age; D008431:Maternal-Fetal Exchange; D010902:Pituitary Gland / Q000196:embryology / Q000378:metabolism*; D011247:Pregnancy; D012756:Sheep; D013250:Steroid Hydroxylases / Q000096:biosynthesis
chemical_list: D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases