Growth factors in renal development.

The formation of all organs during embryogenesis, including the kidney, is dependent on the timed and sequential expression of a number of polypeptide growth factors. Synthesis and actions of one or more members of the insulinlike growth factor (IGF), epidermal growth factor/transforming growth factor-alpha (EGF/TGF-alpha), transforming growth factor-beta (TGF-beta), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), hepatocyte growth factor (HGF), and nerve growth factor (NGF) families have been characterized in the developing metanephric kidney. Studies originating from a number of laboratories have defined the localization of growth factor mRNAs, receptors and peptides, have delineated patterns of growth factor synthesis, have established the growth factor-dependency of embryonic kidney development, and have identified abnormalities of growth factor-expression as potentially causative of aberrancies in metanephrogenesis. The results of these investigations are summarized in this review.