The clonal smooth muscle cell line AlO, derived from fetal rat aorta, binds I-lnsulln-llke growth factor I at a Type 1 insulin-like growth factor receptor. Threonine-59 insulin-like growth factor I, multiplication stimulating activity, and insulin inhibit the binding with IC50 = 10 nM, 84 nM, and 500 nM, respectively. Insulin in high concentrations (>5 piM) completely inhibits I-insulin-like gr...

IGF-1 and growth hormone (GH) interact with insulin to modulate its control of carbohydrate metabolism. A new study (see the related article beginning on page 96) shows that blocking the effect of GH in the presence of low serum IGF-1 concentrations enhances insulin sensitivity.

The insulin-like growth factor (IGF) system composed of two ligands, their receptors and regulatory proteins (acid-labile subunit and IGF-binding proteins) plays a central role in the regulation of growth and development in mammals. In addition to its key role in the stimulation of cellular proliferation and growth, IGF-I has important effects on carbohydrate, protein and bone metabolism. The m...

In vitro invasion and adhesion of stably semaphorin (sema) 3E-transfected PC-3 prostate cancer cells were determined in the presence and absence of transferrin. Invasion and adhesion decreased compared to untransfected cells; however, transferrin reversed the effects. Transferrin differentially regulated E-cadherin and beta-catenin in these cells. Insulin growth factor 3 (IGFBP3) negated the in...

V. Conditions Associated with Genetic IGF-I Resistance in Humans A. African Efe Pygmies B. Leprechaunism and other genetic disorders associated with severe insulin resistance C. Deletions of the distal arm of chromosome 15 D. Rare examples of “idiopathic” short stature associated with elevated circulating levels of IGF-I VI. Conditions Associated with Acquired IGF-I Resistance in Humans A. HIV-...