IGF binding protein-5 (IGFBP-5) modulates the availability of IGF-I to its receptor and potentiates the intestinotrophic action of IGF-I. Our aim was to test the hypothesis that stimulation of intestinal growth due to coinfusion of IGF-I with total parenteral nutrition (TPN) solution is dependent on increased expression of IGFBP-5 through conducting our studies in IGFBP-5 knockout (KO) mice. IG...

To study the effects and mechanisms of insulin-like growth factor I (IGF-I) on brain myelination in vivo, the morphology of myelinated axons and the expression of myelin specific protein genes have been examined in transgenic (Tg) mice that overexpress IGF-I and that those ectopically express IGF binding protein-1 (IGFBP-1), a protein that inhibits IGF-I actions when present in molar excess. Ou...

Glucocorticoid has complex effects on osteoblasts. Several of these changes appear to be related to steroid concentration, duration of exposure, or specific effects on growth factor expression or activity within bone. One important bone growth factor, insulin-like growth factor I (IGF-I), is induced in osteoblasts by hormones such as PGE2 that increase intracellular cAMP levels. In this way, PG...

Insulin-like growth factor (IGF)-I and -II have been cloned from a number of teleost species, but their cellular actions in fish are poorly defined. In this study, we show that both IGF-I and -II stimulated zebrafish embryonic cell proliferation and DNA synthesis in a concentration-dependent manner, whereas insulin had little mitogenic activity. Affinity cross-linking and immunoblotting studies...

Insulin-like growth factor (IGF) I has been shown previously to up-regulate matrix metalloproteinase-2 (MMP-2) production, whereas the interleukin (IL) 10/IL-10 receptor axis has been found to down-regulate MMP-2 synthesis in tumor cells. In this paper, we showed that IL-10 activation of the IL-10 receptor blocked MMP-2 and membrane type 1 (MT1) -MMP transcription and protein synthesis in nonim...

Insulin-like growth factor (IGF) I is a polypeptide hormone important in normal growth and development. Although IGF-I is a mitogen for many cancer cell lines, previous work has suggested that autocrine production of IGF-I is uncommon in cancers of epithelial origin. In this study, expression of IGF-I, its binding proteins, and its receptor were examined in ovarian cancer cell lines and tissues...

Mauras, Nelly, Valerie Quarmby, and Duane C. Bloedow. Pharmacokinetics of insulin-like growth factor I in hypopituitarism: correlation with binding proteins. Am. J. Physiol. 277 (Endocrinol. Metab. 40): E579–E584, 1999.—We investigated the pharmacokinetics of recombinant human insulin-like growth factor I (rhIGF-I) in growth hormone deficiency (GHD). Nine GHD adults [age 25 6 3 (SE) yr] receive...

The insulin-like growth factor I (IGF-I) axis has been proposed to be a significant factor in the development of certain cancers, including colorectal. However, results from epidemiologic studies suggest modest effects on colorectal cancer risk. Using cross-sectional and prospective study designs within the same cohort of men who had at least one adenoma at baseline, we investigated whether pla...