title: Leptin, cortisol, and GH secretion interactions in short normal prepubertal children.
abstract: The hormonal regulation of the ob gene and leptin secretion in humans is still unclear. To investigate the interactions among leptin, cortisol, and GH, we analyzed and time-cross-correlated their spontaneous 24-h secretion in 12 short normal prepubertal children of both sexes (6 females and 6 males). Time-cross-correlation analyses demonstrated that leptin and cortisol were correlated in both a negative and positive fashion. The negative correlation, with cortisol leading leptin by 4 and 3 h for boys and girls, respectively, might reflect the stimulatory effect of CRH on the sympathetic system, which inhibits leptin secretion; the positive correlation, with leptin leading cortisol by 6 and 5 h for boys and girls, respectively, might reflect a direct effect of leptin on CRH secretion in the hypophyseal portal system. Time-cross-correlation analyses also showed a strong positive correlation between GH and leptin concentrations, with GH leading leptin by 5 and 2 h for boys and girls, respectively, suggesting a possible direct leptin-releasing effect of GH on adipocytes. We conclude that cross-correlation analyses of 24-h hormone secretions under baseline physiological conditions suggest that the hypothalamic-pituitary-adrenal axis might have a prevailing inhibitory effect on leptin secretion, whereas leptin might exert a positive effect on the hypothalamic-pituitary-adrenal axis. The relation between GH and leptin could be a direct one and characterized prevalently by a positive effect of GH on leptin secretion. Further investigations using different experimental systems are needed to ascertain the validity of these mathematically educed conclusions.
authors.affiliation: Department of Pediatrics, University of Parma, 43100 Parma, Italy. lucia..ghizzoni@unipr.it
authors.forename: L
authors.initials: L
authors.lastname: Ghizzoni
authors.forename: G
authors.initials: G
authors.lastname: Mastorakos
authors.forename: M E
authors.initials: ME
authors.lastname: Street
authors.forename: G
authors.initials: G
authors.lastname: Mazzardo
authors.forename: A
authors.initials: A
authors.lastname: Vottero
authors.forename: M
authors.initials: M
authors.lastname: Vanelli
authors.forename: S
authors.initials: S
authors.lastname: Bernasconi
mesh_terms: D001827:Body Height; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology*; D003346:Corticotropin-Releasing Hormone / Q000502:physiology; D005260:Female; D019382:Human Growth Hormone / Q000097:blood / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D020738:Leptin / Q000097:blood / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D011627:Puberty; D012016:Reference Values; D012737:Sex Factors
chemical_list: D020738:Leptin; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone