GROWTH-FACTOR REGULATION OF INSULIN-LIKE-GROWTH-FACTOR BINDING-PROTEIN SECRETION BY CULTURED HUMAN GRANULOSA-LUTEAL CELLS

Objective: To examine the effects of epidermal growth factor (EGF), tr ansforming growth factor-beta (TGF-beta), and fibroblast growth factor (FGF) on insulin-like growth factor binding protein (IGFBP) secretion by cultured human granulosa-luteal cells. Design: Granulosa-luteal ce lls obtained at the time of oocyte harvest for IVF were cultured in se rum-free medium in the presence or absence of EGF, TGF-beta, or FGF. C onditioned medium then was analyzed by Western ligand blot and immunor adiometric assays. Setting: An academic medical center. Patient(s): Wo men undergoing IVF. Intervention(s): None. Main Outcome Measure(s): IG FBP-1 secretion. Result(s): By Western ligand blot analysis, IGFBP-1 l evels were 1.4-fold to 7.4-fold higher in conditioned medium from cell s cultured in the presence of EGF than in control medium. By immunorad iometric assay, IGFBP-1 levels increased from 1.6 to 9.9 times over co ntrol. The TGF-beta had no apparent effect, and FGF did not consistent ly stimulate IGFBP-1 secretion. Conclusion(s): The EGF may decrease in trafollicular bioavailable IGF levels by increasing inhibitory IGFBPs, thereby leading to arrest of follicular development Interactions betw een the EGF and IGF systems may be involved in the processes governing human ovarian follicle maturation and atresia. (Fertil Steril(R) 1998 ;70.535-40. (C) 1998 by American Society for Reproductive Medicine.).