INSULIN-LIKE GROWTH-FACTOR BINDING PROTEIN-2, 28-KDA AND 24-KDA INSULIN-LIKE GROWTH-FACTOR BINDING-PROTEIN LEVELS ARE DECREASED IN FLUID OFDOMINANT FOLLICLES, OBTAINED FROM NORMAL AND POLYCYSTIC OVARIES

In order to investigate potential changes in insulin-like growth facto r binding proteins (IGFBPs) during human follicle maturation, we exami ned the IGFBP profiles in follicular fluid from follicles in different stages of maturation. Samples were obtained from ovaries of women wit h regular menstrual cycles and of subjects with cycle abnormalities an d polycystic ovaries (diagnosed as polycystic ovary syndrome (PCOS)) a nd analyzed by Western ligand blotting. IGFBPs of 43 kDa, 37 kDa, 31 k Da, a doublet around 28 kDa and a minor band of 24 kDa were detected i n follicle fluid of normal non-dominant (size < 10 mm) and atretic (an drostenedione/estradiol ratio >4) follicles of both regularly menstrua ting women and PCOS patients. The 43 and 37 kDa IGFBPs could be identi fied as IGFBP-3 and the 31 kDa IGFBP as IGFBP-2, whereas the 28 kDa IG FBP could not be identified as IGFBP-1, all by immunoblotting techniqu es. A dramatic decrease in IGFBP-2, the 28 kDa and 24 kDa IGFBPs was o bserved in follicular fluid of dominant follicles (size > 10 mm) of bo th regular menstruating individuals and one PCOS patient as compared w ith follicular fluid of normal non-dominant or atretic follicles. Thes e observations indicate that the PCOS follicle may not be different fr om normal with respect to IGFBP profiles. Furthermore, these results s uggest that at least one of these IGFBPs might be involved in human fo lliculogenesis.