d-Lys-GHRP-6 does not modify the endocrine response to acylated ghrelin or hexarelin in humans

A. Benso, F. Prodam, B. Lucatello, E. Gramaglia, F. Riganti, H. Schneider, A. J. van der Lely, G. Muccioli, E. Ghigo, F. Broglio

Risultato della ricerca: Contributo su rivistaArticolo in rivistapeer review

Abstract

Acylated ghrelin exerts numerous endocrine and non-endocrine activities via the GH Secretagogue receptor type 1a (GHS-R1a). d-Lys-GHRP-6 has been widely studied in vitro and in vivo in animal studies as GHS-R1a antagonist; its action in humans has, however, never been tested so far. Aim of our study was to verify the antagonistic action of d-Lys-GHRP-6 on the endocrine responses to acylated ghrelin and hexarelin, a peptidyl synthetic GHS, in humans. The effects of different doses of d-Lys-GHRP-6 (2.0 μg/kg iv as bolus or 2.0 μg/kg/h iv as infusion) on both spontaneous and acylated ghrelin- or hexarelin (1.0 μg/kg iv as bolus) -stimulated GH, PRL, ACTH and cortisol levels were studied in six normal volunteers (age [mean ± SEM]: 25.4 ± 1.2 yr; BMI: 22.3 ± 1.0 kg/m2). The effects of d-Lys-GHRP-6 (2.0 μg/kg iv as bolus + 4.0 μg/kg/h iv) on the GH response to 0.25 μg/kg iv as bolus acylated ghrelin was also studied. During saline, spontaneous ACTH and cortisol decrease was observed while non changes occurred in GH and PRL levels. Acylated ghrelin and hexarelin stimulated (p < 0.05) GH, PRL, ACTH and cortisol secretions. d-Lys-GHRP-6 administered either as bolus or a continuous infusion did not modify both spontaneous and acylated ghrelin- or hexarelin-stimulated GH, PRL, ACTH and cortisol secretion. d-Lys-GHRP-6 did not modify even the GH response to 0.25 μg/kg iv acylated ghrelin. In conclusion, d-Lys-GHRP-6 does not affect the neuroendocrine response to both ghrelin and hexarelin. These findings question d-Lys-GHRP-6 as an effective GHS-R1a antagonist for human studies.

Lingua originaleInglese
pagine (da-a)45-49
Numero di pagine5
RivistaNeuropeptides
Volume41
Numero di pubblicazione1
DOI
Stato di pubblicazionePubblicato - feb 2007
Pubblicato esternamente

Fingerprint

Entra nei temi di ricerca di 'd-Lys-GHRP-6 does not modify the endocrine response to acylated ghrelin or hexarelin in humans'. Insieme formano una fingerprint unica.

Cita questo