Ghrelin receptor expression and colocalization with anterior pituitary hormones using a GHSR-GFP mouse line

Reichenbach, Alex, Steyn, Frederick J., Sleeman, Mark W. and Andrews, Zane B. (2012) Ghrelin receptor expression and colocalization with anterior pituitary hormones using a GHSR-GFP mouse line. Endocrinology, 153 11: 5452-5466. doi:10.1210/en.2012-1622

Author Reichenbach, Alex
Steyn, Frederick J.
Sleeman, Mark W.
Andrews, Zane B.
Title Ghrelin receptor expression and colocalization with anterior pituitary hormones using a GHSR-GFP mouse line
Journal name Endocrinology   Check publisher's open access policy
ISSN 0013-7227
Publication date 2012-11
Sub-type Article (original research)
DOI 10.1210/en.2012-1622
Volume 153
Issue 11
Start page 5452
End page 5466
Total pages 15
Place of publication Chevy Chase, MD, United States
Publisher The Endocrine Society
Collection year 2013
Language eng
Abstract Ghrelin is the endogenous ligand for the GH secretagogue receptor (GHSR) and robustly stimulates GH release from the anterior pituitary gland. Ghrelin also regulates the secretion of anterior pituitary hormones including TSH, LH, prolactin (PRL), and ACTH. However, the relative contribution of a direct action at the GHSR in the anterior pituitary gland vs. an indirect action at the GHSR in the hypothalamus remains undefined. We used a novel GHSR-enhanced green fluorescent protein (eGFP) reporter mouse to quantify GHSR coexpression with GH, TSH, LH, PRL, and ACTH anterior pituitary cells in males vs. females and in chow-fed or calorie-restricted (CR) mice. GHSR-eGFP-expressing cells were only observed in anterior pituitary. The number of GHSR-eGFP-expressing cells was higher in male compared with females, and CR did not affect the GHSR-eGFP cell number. Double staining revealed 77% of somatotrophs expressed GHSR-eGFP in both males and females. Nineteen percent and 12.6% of corticotrophs, 21% and 9% of lactotrophs, 18% and 19% of gonadotrophs, and 3% and 9% of males and females, respectively, expressed GHSR-eGFP. CR increased the number of TSH cells, but suppressed the number of lactotrophs and gonadotrophs, expressing GHSR-eGFP compared with controls. These studies support a robust stimulatory action of ghrelin via the GHSR on GH secretion and identify a previously unknown sexual dimorphism in the GHSR expression in the anterior pituitary. CR affects GHSR-eGFP expression on lactotrophs, gonadotrophs, and thyrotrophs, which may mediate reproductive function and energy metabolism during periods of negative energy balance. The low to moderate expression of GHSR-eGFP suggests that ghrelin plays a minor direct role on remaining anterior pituitary cells.
Keyword Ghrelin
Anterior pituitary
Reproductive function
Energy metabolism
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online before print: 7 September 2012.

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2013 Collection
School of Biomedical Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 9 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 8 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Mon, 24 Sep 2012, 16:07:27 EST by Bacsweet Kaur on behalf of School of Biomedical Sciences