title: Prostaglandin E2 enhances AVP-stimulated but not CRF-stimulated ACTH secretion from cultured fetal sheep pituitary cells.
abstract: This study examined the ability of prostaglandin E2 (PGE2) to regulate ACTH secretion from cultured anterior pituitary cells of fetal sheep between days 130 and 140 of gestation (term = 145 days). Corticotrophin-releasing factor (CRF) and arginine vasopressin (AVP) induced dose-dependent (0.1-1000 nmol/l) increases in ACTH secretion from fetal sheep pituitary cells maintained in culture for 6 days, with AVP being significantly (P less than 0.01) more potent than CRF. PGE2 (1000 nmol/l) significantly (P less than 0.05) enhanced the ability of AVP, but not CRF, to stimulate ACTH secretion. However, PGE2 given alone (0.1-1000 nmol/l) had no effect on ACTH secretion. Concomitant administration of CRF and AVP induced a greater release of ACTH than after treatment with either peptide alone, a synergistic interaction which was unaffected by simultaneous administration of PGE2. These results provide evidence for a direct action of PGE2 on ACTH secretion from the fetal sheep pituitary gland via a specific interaction with AVP. This interaction may allow increased fetal plasma concentrations of PGE2, seen during late gestation, to stimulate fetal pituitary-adrenal maturation.
authors.affiliation: MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh.
authors.forename: A N
authors.initials: AN
authors.lastname: Brooks
authors.forename: F
authors.initials: F
authors.lastname: Gibson
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002478:Cells, Cultured; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D015232:Dinoprostone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D010902:Pituitary Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012756:Sheep / Q000502:physiology*; D013268:Stimulation, Chemical
chemical_list: D001127:Arginine Vasopressin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D015232:Dinoprostone