title: Concordant and discordant adrenocorticotropin (ACTH) responses induced by growth hormone-releasing peptide-2 (GHRP-2), corticotropin-releasing hormone (CRH) and insulin-induced hypoglycemia in patients with hypothalamopituitary disorders: evidence for direct ACTH releasing activity of GHRP-2.
abstract: The insulin-induced hypoglycemia test (insulin tolerance test: ITT) and corticotropin-releasing hormone (CRH) test are used to examine the activities of the hypothalamo-pituitary-adrenal (HPA) axis. Growth hormone-releasing peptide-2 (GHRP-2), a potent GH secretagogue, also stimulates adrenocorticotropin (ACTH) secretion. To evaluate the role of GHRP-2 in assessing the HPA axis, we examined 6 patients with various hypothalamo-pituitary disorders, and measured ACTH and cortisol responses during provocative tests (ITT, CRH, and GHRP-2 test). None of the 6 patients showed any significant ACTH or cortisol responses to ITT, but significant ACTH release was observed during CRH and GHRP-2 tests. These findings suggest GHRP-2 may directly stimulate ACTH secretion in patients with hypothalamo-pituitary disorders.
authors.affiliation: Department of Cardiovascular, Respiratory and Metabolic Medicine Graduate School of Medicine, Kagoshima University, Sakuragaoka, Kagoshima, Japan. kurokuma@m.kufm.kagoshima-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Kimura
authors.forename: Akira
authors.initials: A
authors.lastname: Shimatsu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Arimura
authors.forename: Hideki
authors.initials: H
authors.lastname: Mori
authors.forename: Akinori
authors.initials: A
authors.lastname: Tokitou
authors.forename: Michiyo
authors.initials: M
authors.lastname: Fukudome
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakazaki
authors.forename: Chuwa
authors.initials: C
authors.lastname: Tei
mesh_terms: D000304:Adrenal Cortex Function Tests; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000328:Adult; D000368:Aged; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000139:chemically induced* / Q000378:metabolism; D007027:Hypothalamic Diseases / Q000097:blood / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides / Q000494:pharmacology*
chemical_list: D007328:Insulin; D009842:Oligopeptides; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; C091874:growth hormone-releasing peptide-2