Insulin-Like Growth Factor-Binding Proteins in Serum and Other Biological Fluids: Regulation and Functions*

Abstract

I. Introduction II. Characteristics of the IGFBPs III. Target Cell Actions of the IGFBPs A. To modulate IGF actions B. To facilitate storage of IGFs in extracellular matrices C. To exert IGF-independent effects IV. IGF-IGFBP Complexes in Biological Fluids A. Serum B. Milk C. Urine D. Cerebrospinal fluid (CSF) E. Follicular fluid F. Amniotic fluid G. Lymph H. Seminal fluid I. Other biological fluids V. Assays for Circulating Levels of IGFBP A. Western ligand blotting B. Western immunoblotting C. RIA D. Immunoradiometric assay (IRMA) VI. Relative Distribution of IGFBPs in Serum VII. Regulation of Serum IGFBPs A. Physiological conditions B. Development and aging C. Hormonal effects: mechanisms D. Pathological conditions VIII. IGFBP Proteases in Circulation A. Proteases under normal conditions B. Pregnancy-associated proteases C. Proteases under catabolic and disease states IX. Endocrine Functions of IGFBPs in Serum A. To prevent insulin-like effects B. To increase the half-lives of IGFs C. To control the tra...