ECE2007 Poster Presentations (1) (659 abstracts)
Ghrelin effects on spontaneous and stimulated LH secretion in human males
Lorenza Bonelli , Matteo Baldi , Fabio Broglio , Angela Bertagna , Cataldo Di Bisceglie , Milena Tagliabue , Chiara Manieri , Ezio Ghigo & Fabio Lanfranco
Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Turin, Italy, Torino, Italy.
Acylated ghrelin (AG) participates in the modulation of the hypothalamic-pituitary-gonadal axis functions, with a predominantly inhibitory effect upon the reproductive system in animals. Animal studies have shown that ghrelin suppresses LH secretion in vivo, decreases LH responsiveness to GnRH in vitro and partially delays the timing of puberty in males. Aim of this study was to evaluate the effects of AG infusion on spontaneous and stimulated gonadotropin secretion in male subjects. In 6 eugonadal males (age mean±S.E.M.:28.7±1.1 yrs; BMI:22.4±2.1 kg/m2) we evaluated LH and FSH levels every 15 min during: a) i.v. isotonic saline infusion (SAL) from 0 to +480 min; b) i.v. SAL from 0 to +240 min followed by AG (1.0 μg/kg as a bolus at +240 min, and AG infusion 2 μg/kg/h in 500 ml isotonic saline from +240 to +480 min); c) GnRH test (100 μg i.v. as a bolus at +120 min) during saline or AG infusion from 0 to +240 min. No significant changes in FSH pulsatile secretion were recorded in test sessions a) and b). Under SAL infusion, significant LH pulses were recorded in all subjects. AG infusion significantly decreased LH pulse number and frequency, pulse height (MSPH: 0.04±0.02 mU/ml; −84% vs. SAL) and pulse mass (MSPM: 0.65±0.46 mU/ml; −89% vs. SAL). LH and FSH responses during saline (LH peak 18.2±3.9 mU/ml, FSH peak 12.7±2.6 mU/ml) were similar to those recorded during AG (LH peak 21.6±4.4 mU/ml, FSH peak 11.2±2.9 mU/ml). These findings demonstrate that AG inhibits pulsatile LH secretion but not LH responsiveness to GnRH in males. Therefore ghrelin, at least the acylated form, exerts an inhibitory effect on the gonadal axis in men through a hypothalamic mechanism.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more