Insulin-like growth factor binding protein-1 in female reproductive functions.

Multiple lines of evidence suggest that growth factors and related proteins are involved in the regulation of reproductive functions. It appears that hormones and local regulators control each other's production and action. Thus, the same regulatory factor may have different effects depending on the context in which it acts. Insulin-like growth factor-binding protein-1 (IGEBP-1) is a member of the family of soluble proteins that bind insulin-like growth factors (IGF-I and IGF-II) and modulate their biological actions at the cellular level. In the reproductive tract, endometrium and ovarian granulosa-luteal cells express IGFBP-1 mRNA and secrete the protein at a certain stage of differentiation. During pregnancy, IGFBP-1 is a major secretory product of decidualized endometrium. This report summarizes the current views on IGFBP-1 with special regard to its synthesis, regulation and potential role in female reproductive tissues.