[Insulin-like growth factors and ovarian function]

Insulin-like growth factors (IGF) are important in physiology and function of the human ovary. Intraovarian peptides may have a potential for local modulation of follicular development serving as intercellular mediator between the ovarian cells. IGFs constitute a family of homologous, low molecular weight, single chain polypeptide growth factors named for their remarkable structural and functional similarity to insulin. Studies have suggested its synthesis in several extrahepatic tissues wherein it may play autocrine or paracrine regulatory roles. IGF-1 stimulates DNA synthesis in human granulosaluteal cells. In synergism with FSH, IGF-1 stimulates aromatase activity, enhances proteoglycan biosynthesis, increases progesterone action. IGF-1 and IGF-2 stimulate human oocyte maturation. Hyperandrogenism of any type has been suggested to be due to an effect of IGFs mediated through their receptors or their binding proteins.