title: Naloxone-induced ACTH release in man is inhibited by clonidine.
abstract: 1. Adrenergic mechanisms play an important role in regulation of ACTH release. We used the alpha 2-adrenergic agonist, clonidine, as a central nervous system inhibitor of ACTH release to see if it would alter naloxone-induced ACTH secretion in normal human volunteers. 2. There was a significant blunting of the mean peak level of ACTH and the mean peak change of ACTH from basal as well as the area under the ACTH-time curve when clonidine was given prior to naloxone. 3. We conclude that clonidine, by blocking central noradrenergic pathways, which stimulate corticotropin-releasing hormone secretion, inhibits naloxone-induced ACTH secretion. This suggests that naloxone causes ACTH release through these same central noradrenergic pathways.
authors.affiliation: Neuroendocrine Research Unit, University Department of Medicine, Brisbane, Queensland, Australia.
authors.forename: R V
authors.initials: RV
authors.lastname: Jackson
authors.forename: J E
authors.initials: JE
authors.lastname: Grice
authors.forename: A J
authors.initials: AJ
authors.lastname: Jackson
authors.forename: G I
authors.initials: GI
authors.lastname: Hockings
mesh_terms: D000284:Administration, Oral; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000328:Adult; D003000:Clonidine / Q000008:administration & dosage / Q000494:pharmacology*; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009270:Naloxone / Q000008:administration & dosage / Q000037:antagonists & inhibitors*; D013997:Time Factors
chemical_list: D009270:Naloxone; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003000:Clonidine; D006854:Hydrocortisone