Table of Contents
ISRN Obesity
Volume 2013, Article ID 751401, 4 pages
http://dx.doi.org/10.1155/2013/751401
Research Article

Effect of Ghrelin on Hepatic IGF-Binding Protein-1 Production

School of Health, Nursing and Midwifery, University of the West of Scotland, Paisley Campus, Paisley PA1 2BE, UK

Received 28 November 2012; Accepted 1 January 2013

Academic Editors: E. K. Naderali, S. J. Pintauro, and J. Saleh

Copyright © 2013 Moira S. Lewitt. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ghrelin plays key roles in energy homeostasis by central and peripheral actions that include effects on insulin signalling pathways in liver. Insulin is an important inhibitor of production by hepatocytes of insulin-like growth factor-binding protein-1 (IGFBP-1) which has an endocrine role to inhibit IGF availability. The effects of ghrelin, insulin, an AMPK activator, and an AMPK inhibitor on IGFBP-1 secretion were studied in H4-II-E rat liver cells. Ghrelin (100 nM) blocked the inhibitory effect of a maximally effective concentration of insulin (10 ng/mL) on IGFBP-1 secretion during a 5 h incubation period ( ) in the absence and presence of an AMPK inhibitor. Ghrelin, alone, had no effect on IGFBP-1 production, but enhanced secretion independently of insulin under conditions of AMPK activation ( ). In conclusion, IGFBP-1 is identified as a novel target of ghrelin action in liver that may contribute to its metabolic effects in obesity.