Insulin-like growth factor II in follicular fluid of the patients with in vitro fertilization and embryo transfer.
OBJECTIVE
To investigate whether insulin-like growth factor II (IGF-II) is present in follicular fluids (FF) and whether IGF-II in FF plays an important role on human ovarian function.


METHODS
Insulin-like growth factor II concentrations were measured using an RIA technique in 46 samples of human FF obtained from 20 patients who were undergoing IVF and ET. The distribution profiles of unsaturated IGF-II binding protein were also investigated. Moreover, the effect of IGF-II on steroidogenesis by cultured granulosa cells (GCs) obtained simultaneously in the IVF-ET program was investigated.


RESULTS
The IGF-II levels in FF (92.7 +/- 7.5 nmol/L) were approximately eight times greater than those of IGF-I (11.4 +/- 1.0 nmol/L), and significant positive correlations were observed between these IGFs in FF. By Sephadex G-150 gel-chromatography of FF, two apparent peaks of unsaturated IGF-II binding protein could be detected in the high molecular weight (MW) (150 kd) and low MW (approximately 36 to 38 kd) regions. Additionally, IGF-II dose dependently increased the release of P and E2 from the cultured human GCs.


CONCLUSIONS
These findings suggest that the large quantity of IGF-II in FF may play possibly some roles in the ovarian steroidogenesis.
Kubota
T
T
Department of Obstetrics and Gynecology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
Kamada
S
S
Ohara
M
M
Taguchi
M
M
Sakamoto
S
S
Shimizu
Y
Y
Aso
T
T
D000328:Adult; D002352:Carrier Proteins / Q000032:analysis; D002478:Cells, Cultured; D004624:Embryo Transfer; D004958:Estradiol / Q000032:analysis; D005260:Female; D005307:Fertilization in Vitro; D015571:Follicular Fluid / Q000737:chemistry*; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007246:Infertility / Q000628:therapy; D018971:Insulin-Like Growth Factor Binding Protein 2; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007335:Insulin-Like Growth Factor II / Q000032:analysis* / Q000494:pharmacology; D011374:Progesterone / Q000032:analysis / Q000378:metabolism; D011863:Radioimmunoassay
D002352:Carrier Proteins; D018971:Insulin-Like Growth Factor Binding Protein 2; D011374:Progesterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II