Expression of insulin-like growth factor (IGF), IGF receptor, and IGF-binding protein messenger ribonucleic acids in luteinized granulosa cells from different size follicles after controlled ovarian hyperstimulation.

PURPOSE: This study was conducted to determine the gene expression of insulin-like growth factors (IGFs), their receptors, and binding proteins (IGFBPs) in human luteinized granulosa cells collected during ovum retrieval.

METHODS

cDNA probes were used to analyze the gene expression of IGF-I, IGF-II, IGF type 1 receptor (IGFR-1), IGF type 2 receptor (IGFR-2), and IGFBP-1 to -6 in luteinized granulosa cells.

RESULTS

The levels of IGFBP-5 transcripts of the luteinized granulosa cells increased with increasing follicular fluid (FF) volume when follicles were grouped into 3 volume catagories of < or = 1.5 mL: > 1.5 mL but < or = 4.5 mL; and > 4.5 mL (0.28 +/- 0.64 vs. 0.41 +/- 0.76 vs. 0.46 +/- 0.92, p = 0.037).

CONCLUSIONS

The increased levels of IGFBP-5 transcripts in luteinized granulosa cells found with increased follicular fluid volume after COH may favor a shift toward diminished action of IGFs in larger follicles immediately prior to ovulation.