Diabetologie und Stoffwechsel 2007; 2 - V13
DOI: 10.1055/s-2007-982108

Increased growth and elevated IGF-1 serum concentrations in mice with an adipose tissue specific deletion of the Igf-1 receptor

N Klöting 1, L Koch 2, T Wunderlich 2, M Kern 1, W Krone 3, JC Brüning 2, M Blüher 1
  • 1University of Leipzig, Department of Internal Medicine III, Leipzig, Germany
  • 2University of Cologne and Center of Molecular Medicine Cologne (CMMC), Department of Mouse Genetics and Metabolism, Institute for Genetics, Cologne, Germany
  • 3University of Cologne and Center of Molecular Medicine Cologne (CMMC), Department of Internal Medicine II, Cologne, Germany

Insulin-like growth factor-1 (IGF-1) and the IGF-1 receptor have been implicated in the regulation of adipocyte differentiation and lipid accumulation in vitro. To investigate the role of IGF-1 receptor in vivo, we created mice with fat-specific disruption of the IGF-1 receptor gene (FIGF-1RKO mice) using the Cre-loxP system. FIGF-1RKO mice have remarkably increased somatic growth most likely as a consequence of elevated IGF-1 serum concentrations. Higher circulating IGF-1 levels could be due to increased IGF-1 expression both in liver and epigonadal adipose tissue, suggesting that adipose tissue plays a role in the regulation of IGF-1 serum concentrations. FIGF-1RKO mice exhibit increased adipose tissue mass with a predominantly increased lipid accumulation in epigonadal fat pads. Insulin-stimulated glucose uptake into adipocytes was unaffected by the deletion of the IGF-1 receptor. Thus, IGF-1 receptor signalling in adipocytes is not crucial for the development and differentiation of adipose tissue, but seems to participate in the regulation of IGF-1 serum concentration.