title: The endocrine response to ghrelin as a function of gender in humans in young and elderly subjects.
abstract: Ghrelin modulates somatotroph, lactotroph, corticotroph, and insulin secretion and glucose metabolism. To clarify the influence of gender and age on the endocrine actions of ghrelin in humans, we studied the effects of ghrelin (1.0 micro g/kg iv) or placebo on GH, prolactin (PRL), ACTH, cortisol, insulin, glucagon, and glucose levels in 18 young subjects (YS) and 16 elderly subjects (ES) of both genders. The GH response to GHRH (1.0 micro g/kg iv) was also studied. The GH response to ghrelin in YS was higher (P < 0.01) than in ES and both higher (P < 0.01) than to GHRH, without gender-related differences. In YS ghrelin also induced: 1) gender-independent increase (P < 0.01) in PRL, ACTH, and cortisol levels; 2) gender-independent increase in glucose levels (P < 0.01); 3) decrease (P < 0.01) in insulin levels in male YS; and 4) no change in glucagon. In ES, ghrelin induced gender-independent PRL, ACTH, and cortisol responses (P < 0.01). In ES ghrelin elicited gender-independent transient decrease in insulin (P < 0.01) coupled with increase in glucose levels (P < 0.05). In conclusion, the GH-releasing effect of ghrelin is independent of gender but undergoes age-related decrease. The effect of ghrelin on lactotroph and corticotroph secretion is age and gender independent. In both ES and YS, ghrelin influences insulin secretion and glucose metabolism.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Turin, 10126 Turin, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Broglio
authors.forename: Andrea
authors.initials: A
authors.lastname: Benso
authors.forename: Carlotta
authors.initials: C
authors.lastname: Castiglioni
authors.forename: Cristina
authors.initials: C
authors.lastname: Gottero
authors.forename: Flavia
authors.initials: F
authors.lastname: Prodam
authors.forename: Silvia
authors.initials: S
authors.lastname: Destefanis
authors.forename: Carlotta
authors.initials: C
authors.lastname: Gauna
authors.forename: Aart Jan
authors.initials: AJ
authors.lastname: van der Lely
authors.forename: Romano
authors.initials: R
authors.lastname: Deghenghi
authors.forename: Mario
authors.initials: M
authors.lastname: Bo
authors.forename: Emanuela
authors.initials: E
authors.lastname: Arvat
authors.forename: Ezio
authors.initials: E
authors.lastname: Ghigo
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000368:Aged; D000375:Aging; D001786:Blood Glucose / Q000032:analysis; D005260:Female; D054439:Ghrelin; D005934:Glucagon / Q000097:blood; D006728:Hormones / Q000097:blood*; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D036361:Peptide Hormones / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism; D010919:Placebos; D011388:Prolactin / Q000097:blood; D012727:Sex Characteristics
chemical_list: D001786:Blood Glucose; D054439:Ghrelin; D006728:Hormones; D007328:Insulin; D036361:Peptide Hormones; D010919:Placebos; D019382:Human Growth Hormone; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D005934:Glucagon; D006854:Hydrocortisone