Resumen Objetivos El factor de crecimiento insulínico tipo 1 (IGF-I) es el biomarcador más ampliamente utilizado para diagnóstico y seguimiento los trastornos relacionados con crecimiento, aunque su cuantificación en suero implica una serie dificultades. De este modo, se han observado discrepancias las concentraciones IGF-I según ensayo empleado, especialmente contexto superiores o inferiores a...

We showed previously that insulin-like growth factor I (IGF-I) is detectable in small cell lung cancer (SCLC) tumor biopsies and cell lines and that recombinant human IGF-I stimulates DNA synthesis in SCLC cells. Here we report further studies on the role of IGF-I in 2 SCLC cell lines: HC12, classic; and ICR-SC17, variant. Immunoreactive IGF-I was detected in medium conditioned by HC12 but not ...

To characterize and study the variations of IGF-I binding during the development of trout muscle cells, in vitro experiments were conducted using myocyte cultures, and IGF-I binding assays were performed in three stages of cell development: mononuclear cells (day 1), small myotubes (day 4), and large myotubes (day 10). Binding experiments were done by incubating cells with IGF-I for 12 h at 4 d...

analysis showed that this was a splice variant of the insulin-like growth factor-I (IGF-I) gene, although its 3 exons were different from the liver or systemic type of IGF-I. However, it was noted that muscle also expresses the systemic type of IGF-I (IGF-IEa). The terminology for the IGF-I variants is a problem when attempting to apply it to nonhepatic tissues and to different species. Also, w...

IGF-I promotes growth during postnatal development via both endocrine and autocrine actions. In pcd mice (pcd/pcd), we previously found that IGF-I mRNA expression was decreased in cerebellar Purkinje cells as they underwent apoptosis. To investigate the endocrine function of IGF-I, we examined hepatic IGF-I mRNA by Northern hybridization, circulating IGF-I peptide by radioimmunoassay, and circu...

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...

Insulin-like growth factor-I (IGF-I) and -II are important local regulators of bone metabolism, but their role as determinants of human bone mass is still unclear. In the present study, we analyzed the concentration of IGF-I and -II in the bone matrix of 533 human biopsies from the iliac crest that were obtained during surgery for early breast cancer. There was an inverse association of bone ma...

The existing literature on serum insulin-like growth factor I (IGF-I) levels in insulin-dependent diabetes mellitus (IDDM) is conflicting. Free IGF-I may have greater physiological and clinical relevance than total IGF-I. Recently, a validated method has been developed to measure free IGF-I levels in the circulation. Serum free and total IGF-I, IGF-binding protein-1 (IGFBP-1), and IGFBP-3 level...

NMR spectroscopy studies and biosensor interaction analysis of native and site-directed mutants of insulin-like growth factor I (IGF-I) was applied to identify the involvement of individual residues in IGF-I binding to IGF-binding protein 1 (IGFBP-1). Backbone NMR chemical shifts were found to be affected by IGFBP-1 binding in the following residues: Pro2, Glu3, Cys6, Gly7, Gly19, Pro28-Gly30, ...