title: Insulin-like growth factor binding-protein-3 (IGFBP-3).
abstract: The IGF system comprises two IGFs (IGF-1, IGF-2), two IGF-receptors (IGF-R1, IGF-R2), and six IGF binding proteins (IGFBPs) with a high affinity for IGFs. The IGFBPs, of which IGFBP-3 is the most abundant in postnatal blood, link with IGFs and prevent them from being degraded; they also facilitate IGF transport through body compartments. The interaction between IGFs and their specific receptors is partly regulated by structural modifications inherent to the IGFBPs. IGFBPs also have IGF-independent biological effects. Since serum IGFBP-3 is GH-dependent and correlates quantitatively with GH secretion, its measurement is useful in tests of abnormal GH secretion. Particularly during childhood, IGFBP-3 values play an important role in ascertaining alterations in GH secretion and action (i.e., primary IGF deficiency states). A new role for IGFBP-3 and other IGFBPs with natural or altered structures is likely to be established through current studies investigating their application in promoting apoptotic processes in malignancies.
authors.affiliation: Division of Paediatric Endocrinology, University Children's Hospital, Tübingen, Germany. Electronic address: michael.ranke@gmx.de.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Ranke
mesh_terms: D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood* / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I
keywords: IGF system; IGFBPs; diagnostic role of IGFBP-3; functional role of IGFBPs