Insulin-like growth factors: the ovarian connection

A large body of information now supports the existence of a complete intraovarian insulin-like growth factor (IGF) system replete with ligands, receptors, and binding proteins. Although much remains to be learned, the emerging consensus would suggest that the intraovarian IGF system is concerned largely with the amplification of gonadotrophin hormonal action for the facilitation of follicular growth and development. Future studies are likely to address the central issue of indispensability and the documentation of a meaningful in vivo role for this and related putative intraovarian regulators.