HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 292/5/E1483    most recent 00417.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Davies, J. S. Articles by Wells, T. Search for Related Content PubMed PubMed Citation Articles by Davies, J. S. Articles by Wells, T.

Adiposity profile in the dwarf rat: an unusually lean model of profound growth hormone deficiency

¹School of Biosciences, Cardiff University, Cardiff; ²Division of Molecular Neuroendocrinology, National Institute of Medical Research, London, United Kingdom; ³Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio; ⁴Department of Child Health, Wales College of Medicine, Cardiff University, Cardiff, United Kingdom; and ⁵Edison Biotechnology Institute, Ohio University, Athens, Ohio

Submitted 14 July 2006 ; accepted in final form 15 January 2007

This study describes the previously uncharacterized ontogeny and regulation of truncal adipose reserves in the profoundly GH-deficient dwarf (dw/dw) rat. We show that, despite normal proportionate food intake, dw/dw rats develop abdominal leanness and hypoleptinemia (circulating leptin halved in dw/dw males, P < 0.05) during puberty. This contrasts with the hyperleptinemia seen in moderately GH-deficient Tgr rats (circulating leptin doubled at 6 wk of age, P < 0.05) and in GH receptor-binding protein (GHR/BP)-null mice (circulating leptin doubled; P < 0.05). This lean/hypoleptinemic phenotype was not completely normalized by GH treatment, but dw/dw rats developed abdominal obesity in response to neonatal MSG treatment or maintenance on a high-fat diet. Unlike Tgr rats, dw/dw rats did not become obese with age; plasma leptin levels and fat pad weights became similar to those in wild-type rats. In contrast with truncal leanness, tibial marrow adiposity was normal in male and doubled in female dwarves (P < 0.01), this increase being attributable to increased adipocyte number (P < 0.01). Neonatal MSG treatment and high-fat feeding elevated marrow adiposity in dw/dw rats by inducing adipocyte enlargement (P < 0.05). These results demonstrate that, despite lipolytic influence of GH, severe GH deficiency in dw/dw rats is accompanied by a paradoxical leanness. This lean/hypoleptinemic phenotype is not solely attributable to reduced GH signaling and does not appear to result from a reduction in nutrient intake or the ability of dw/dw adipocytes to accumulate lipid. Disruption of preadipocyte differentiation or adipocyte proliferation in the dw/dw rat may lead to the development of this unusually lean/hypoleptinemic phenotype.

adipose tissue; bone marrow fat; leptin; dwarfism

This article has been cited by other articles:

				C. R. González, J. E. Caminos, M. J. Vázquez, M. F. Garcés, L. A. Cepeda, A. Ángel, A. C. González, M. E. García-Rendueles, S. Sangiao-Alvarellos, M. López, et al. Regulation of visceral adipose tissue-derived serine protease inhibitor by nutritional status, metformin, gender and pituitary factors in rat white adipose tissue J. Physiol., July 15, 2009; 587(14): 3741 - 3750. [Abstract] [Full Text] [PDF]

				A. E. Stevenson, B. A. J. Evans, E. F. Gevers, C. Elford, R. W. J. McLeod, M. J. Perry, M. M. El-Kasti, K. T. Coschigano, J. J. Kopchick, S. L. Evans, et al. Does adiposity status influence femoral cortical strength in rodent models of growth hormone deficiency? Am J Physiol Endocrinol Metab, January 1, 2009; 296(1): E147 - E156. [Abstract] [Full Text] [PDF]