Eur J Endocrinol
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

DOI: 10.1530/eje.0.1510223
European Journal of Endocrinology, Vol 151, Issue 2, 223-231
Copyright © 2004 by European Society of Endocrinology
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jevdjovic, T
Right arrow Articles by Zapf, J
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jevdjovic, T
Right arrow Articles by Zapf, J
Articles

Effects of insulin--like growth factor-I treatment on the endocrine pancreas of hypophysectomized rats: comparison with growth hormone replacement

T Jevdjovic, C Maake, E Eppler, E Zoidis, M Reinecke, and J Zapf

Division of Neuroendocrinology, Institute of Anatomy, University of Zurich, Winterthurerstr. 190, CH-8057 Zurich, Switzerland.

BACKGROUND: In GH-deficient humans, GH and IGF-I treatment cause opposite effects on serum insulin concentrations and insulin sensitivity. This finding contrasts with the somatomedin hypothesis that IGF-I mediates GH action, as postulated for skeletal growth, and raises the question whether GH-induced IGF-I acts on the endocrine pancreas in the same way as administered IGF-I. OBJECTIVE: To compare the effects of the two hormones on the endocrine pancreas of hypophysectomized rats. METHODS: Animals were infused for 2 days, via miniosmotic pumps, with IGF-I (300 microg/day), GH (200 mU/day) or vehicle. We measured (i) glucose, IGF-I, insulin, C-peptide and glucagon in serum and (ii) IGF-I, insulin and glucagon mRNAs and peptides in the pancreas by radioimmunoassay, immunohistochemistry and northern analysis. RESULTS: Both GH and IGF-I treatment increased serum and pancreatic IGF-I but, unlike GH, IGF-I treatment strongly reduced serum insulin and C-peptide (and, to a lesser extent, serum glucagon). Nevertheless, the animals did not become hyperglycaemic. GH, but not IGF-I, increased pancreatic insulin and glucagon content, as also indicated by immunohistochemistry, and increased IGF-I mRNA. Neither GH nor IGF-I caused significant changes in insulin and glucagon mRNA. CONCLUSIONS: The decrease in serum insulin and C-peptide by IGF-I treatment without significant changes in insulin gene expression and pancreatic insulin content suggests inhibition of insulin secretion. Within this setting, the absence of hyperglycaemia points to enhanced insulin sensitivity, although an insulin-like action of infused IGF-I may have partially compensated for the decreased insulin concentrations. GH-induced circulating or pancreatic IGF-I, or both, does not mimic the pancreatic effects of infused IGF-I in the absence of GH, suggesting that GH may counteract the action of GH-induced IGF-I on the endocrine pancreas.


This article has been cited by other articles:


Home page
 Endocr Relat CancerHome page
P L Jeffery, R E Murray, A H Yeh, J F McNamara, R P Duncan, G D Francis, A C Herington, and L K Chopin
Expression and function of the ghrelin axis, including a novel preproghrelin isoform, in human breast cancer tissues and cell lines
Endocr. Relat. Cancer, December 1, 2005; 12(4): 839 - 850.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Cancer Res.Home page
A. H. Yeh, P. L. Jeffery, R. P. Duncan, A. C. Herington, and L. K. Chopin
Ghrelin and a Novel Preproghrelin Isoform Are Highly Expressed in Prostate Cancer and Ghrelin Activates Mitogen-Activated Protein Kinase in Prostate Cancer
Clin. Cancer Res., December 1, 2005; 11(23): 8295 - 8303.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2004 European Society of Endocrinology.