title: Submaximal doses of ghrelin do not inhibit gonadotrophin levels but stimulate prolactin secretion in postmenopausal women.
abstract: OBJECTIVE
  An inhibitory effect of ghrelin on gonadotrophin secretion has been reported in normally menstruating women possibly modulated by endogenous oestrogen. The aim of this study was to examine the effect of ghrelin on gonadotrophin and prolactin (PRL) secretion in oestrogen-deprived postmenopausal women.
  
  
  METHODS
  Prospective intervention study.
  
  
  METHODS
  Ten healthy postmenopausal volunteer women were studied during two 15-days periods of oestrogen treatment (A and B) a month apart. Four experiments (Exp) were performed in total, two on day 1 (Exp 1A and Exp 1B) and two on day 15 (Exp 15A and Exp 15B) of the two periods. The women received in Exp 1A and in Exp 15A two iv injections of ghrelin (0.15 μg/kg at time 0 minute and 0.30 μg/kg at time 90 minutes) and in Exp1B and in Exp 15B normal saline (2 mL), respectively. Blood samples were taken at -15, 0, 30, 60, 90, 120, 150 and 180 minutes.
  
  
  RESULTS
  After oestrogen treatment, late follicular phase serum oestradiol levels were attained on day 15 of periods A and B. Ghrelin administration did not affect serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), whereas it increased significantly those of growth hormone (GH) and PRL. In Exp 15A, serum PRL increment in response to ghrelin (area under the curve, net increment) was significantly greater than in Exp 1A (P<.05).
  
  
  CONCLUSIONS
  This study demonstrates for the first time that in oestrogen-deprived postmenopausal women, ghrelin administration affects neither FSH nor LH levels but stimulates PRL secretion, that is amplified by exogenous oestrogen administration.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Christina I
authors.initials: CI
authors.lastname: Messini
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Malandri
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Anifandis
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Dafopoulos
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Georgoulias
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Sveronis
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Garas
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Daponte
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Ioannis E
authors.identifier: http://orcid.org/0000-0002-3345-3108
authors.initials: IE
authors.lastname: Messinis
mesh_terms: D000368:Aged; D004967:Estrogens / Q000008:administration & dosage*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D054439:Ghrelin / Q000008:administration & dosage* / Q000494:pharmacology; D006062:Gonadotropins / Q000037:antagonists & inhibitors*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood / Q000187:drug effects*; D011388:Prolactin / Q000187:drug effects / Q000378:metabolism*; D011446:Prospective Studies
chemical_list: D004967:Estrogens; D054439:Ghrelin; D006062:Gonadotropins; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
keywords: 
  FSH
  ; 
  PRL
  ; LH; ghrelin; oestrogen