title: Copeptin under glucagon stimulation.
abstract: Stimulation of growth hormone (GH) and adrenocorticotropic hormone (ACTH) secretion by glucagon is a standard procedure to assess pituitary dysfunction but the pathomechanism of glucagon action remains unclear. As arginine vasopressin (AVP) may act on the release of both, GH and ACTH, we tested here the role of AVP in GST by measuring a stable precursor fragment, copeptin, which is stoichiometrically secreted with AVP in a 1:1 ratio. ACTH, cortisol, GH, and copeptin were measured at 0, 60, 90, 120, 150, and 180 min during GST in 79 subjects: healthy controls (Group 1, n = 32), subjects with pituitary disease, but with adequate cortisol and GH responses during GST (Group 2, n = 29), and those with overt hypopituitarism (Group 3, n = 18). Copeptin concentrations significantly increased over baseline 150 and 180 min following glucagon stimulation in controls and patients with intact pituitary function but not in hypopituitarism. Copeptin concentrations were stimulated over time and the maximal increment correlated with ACTH, while correlations between copeptin and GH were weaker. Interestingly, copeptin as well as GH secretion was significantly attenuated when comparing subjects within the highest to those in the lowest BMI quartile (p < 0.05). Copeptin is significantly released following glucagon stimulation. As this release is BMI-dependent, the time-dependent relation between copeptin and GH may be obscured, whereas the close relation to ACTH suggests that AVP/copeptin release might be linked to the activation of the adrenal axis.
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, Lodz, Poland.
authors.forename: Krzysztof C
authors.initials: KC
authors.lastname: Lewandowski
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, Lodz, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Lewiński
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, Lodz, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Skowrońska-Jóźwiak
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Stasiak
authors.affiliation: Faculty of Mathematics and Computer Science, University of Lodz, Lodz, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Horzelski
authors.affiliation: Experimental and Clinical Endocrinology Med Clinic I, University of Luebeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. Georg.Brabant@manchester.ac.uk.|Department of Endocrinology, The Christie Manchester Academic Health Science Centre, Wilmslow Rd, Manchester, M20 4BX, UK. Georg.Brabant@manchester.ac.uk.
authors.forename: Georg
authors.initials: G
authors.lastname: Brabant
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D005934:Glucagon; D006020:Glycopeptides / Q000097:blood*; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D006020:Glycopeptides; C048197:copeptins; D000324:Adrenocorticotropic Hormone; D013006:Growth Hormone; D005934:Glucagon; D006854:Hydrocortisone
keywords: ACTH; Copeptin; Cortisol; GH; Glucagon stimulation test; Hypopituitarism