IGFBPs

Perform a provocative test to measure GH, IGF-I, and/or IGFBP-3 levels. 

IGFBP-3 insulin-like growth factor binding protein 3... 

R17. Ross, R. J Miell, J. P Holly, J. M. P., Maheshwari, H., Norman, M., Farhana Abdulla, A., and Buchanant, C. R., Levels of GH binding activity, IGFBP-I, insulin, blood glucose, and cortisol in intensive care patients. Clin. Endocrinol. 35,361-367 (1991). 

Gunnell, D, SE Oliver, TJ Peters et al. 2003. Are diet-prostate cancer associations mediated by the IGF axis A cross-sectional analysis of diet, IGF-1 and IGFBP-3 in healthy middle-aged men. Br J Cancer 88(11) 1682-1686. 

Perry, AS, B Loftus, R Moroose et al. 2007. In silico mining identifies IGFBP-3 as a novel target of methylation in prostate cancer. BrJ Cancer 96 1587-1594. 

No difference in IGF-1 secretion by cells treated with 20-60 pM lycopene IGFBP-3 secretion increased by 1.5- to 2-fold... 

Increased cellular IGFBP-3 with 60pM lycopene independent of IGF-1 stimulation Lycopene down-regulated IGF-1 stimulated IGF-IR production... 

Increased by 1.5- to 2-fold at 40 pM in cells and culture media IGF-1 stimulation + lycopene increased IGFBP-3 levels while IGF-1 alone decreased BP by twofold No difference IGF-1 stimulated IGF-IR expression but added lycopene decreased its expression... 

Horney, M.J. et al. (2001) Synthesis and characterization of insulin-like growth factor (IGF)-l photoprobes selective for the IgG-binding proteins (IGFBPs) photoaffinity labeling of the IGF-binding domain on IGFBP-2./. Biol. Chem. 276(4), 2880-2889. 

The liver represents the major site of synthesis of the IGFs, from where they enter the blood stream, thereby acting in a classical endocrine fashion. A wide variety of body cells express IGF receptors, of which there are two types. Furthermore, IGFs are also synthesized in smaller quantities at numerous sites in the body and function in an autocrine or paracrine manner at these specific locations. IGF activity is also modulated by a family of IGFBPs, of which there are at least six. 

IGFBPs are widely expressed, but high levels of BPl and BP2 in particular are found in the liver. The bulk of serum IGF-1 and -2 is found complexed to BP3 and an acid-labile polypeptide. The remaining molecules of serum IGFs are usually found complexed to BPl, BP2 or BP4. 

The IGFBPs probably fulfil several biological functions in addition to preventing hypoglycaemia. They likely protect the mitogen (e.g. from proteolysis) in the blood, and appear to significantly increase the IGF s plasma half-life. They also probably modulate IGF function locally at the surface of IGF-sensitive cells. 

IGFs (in particular IGF-1 and also IGFBP-1) are localized within various areas of the kidney. Direct infusion of IGF-1 influences (usually enhances) renal function by a number of means, including promoting ... 

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