Effects of leptin and neuropeptide Y on function of human ovarian granulosa cells in vitro

Objective: To investigate the effects of leptin and neuropeptide Y on steroidogenesis of human ovarian granulosa cells in vitro. Methods: Human ovarian granulosa cells were isolated from follicular fluid obtained during oocyte retrieval of in vitro fertilization-embryo transfer program and cultured for 2 days with various concentration of leptin(1,10,100 ng/ml) or neuropeptide Y (1×10-6, 1×10-7, 1×10-8 mol/L) alone or both,or with the combination of human chorionic gonadotropin (hCG 0, 20 IU/L). The medium was collected for estradiol (E2) and progesterone (P) measurements. Results: (1)Whether hCG existed or not, the adding of leptin did not alter estradiol and progesterone production by human granulosa cells (P>0.05).(2) Only when the concentration of neuropeptide Y was at 1×10-7mol/L,estradiol level was lower than that in the control (P<0.05).(3) The levels of estradiol in neuropeptide Y (1×10-7mol/L) plus hCG group were significantly higher than those with neuropeptide Y alone(P<0.05). (4) In the absence of hCG, the levels of estradiol in neuropeptide Y (1×10-7mol/L)plus leptin (10 ng/ml) group were significantly higher than those with neuropeptide Y(1×10-7mol/L)alone(P<0.05).Conclusions: (1)Leptin alone produced no direct effect on secretion of E2 and P from granulosa cells in vitro.(2)Neuropeptide Y alone may inhibit the secretion of E2, but the inhibition would probably be blocked with the presentation of hCG.(3)Leptin probably blocked the inhibition of neuropeptide Y on E2 secretion, and this may indicate that there were some coordination between leptin and neuropeptid Y on the level of ovarian function.

Objective： To investigate the effects of leptin and neuropeptide Y on steroidogenesis of human ovarian granulosa cells in vitro. Methods： Human ovarian granulosa cells were isolated from follicular fluid obtained during oocyte retrieval of in vitro fertilization-embryo transfer program and cultured for 2 days with various concentration of leptin（1, 10, 100 ng/ml） or neuropeptide Y （1 × 10^-6 , 1 × 10^-7 , 1 × 10^-8 mol/L） alone or both,or with the combination of human chorionic gonadotropin （hCG 0, 20 IU/L）. The medium was collected for estradiol （E2） and progesterone （P） measurements. Results： （1）Whether hCG existed or not, the adding of leptin did not alter estradiol and progesterone production by human granulosa cells （P〈 0. 05）. （2） Only when the concentration of neuropeptide Y was at 1 × 10^-7mol/L,estradiol level was lower than that in the control （P^0.05）. （3） The levels of estradiol in neuropeptide Y （1 × 10^-7mol/L） plus hCG group were significantly higher than those with neuropeptide Y alone（P〈0.05）. （4） In the absence of hCG, the levels of estradiol in neuropeptide Y （1 × 10^-7 mol/L）plus leptin （10 ng/ml） group vcere significantly higher than those with neuropeptide Y（1 × 10^-7 mol/L）alone（P〈0.05）. Conclusions： （1）Leptin alone produced no direct effect on secretion of E2 and P from granulosa cells in vitro. （2） Neuropeptide Y alone may inhibit the secretion of E2, but the inhibition would probably be blocked with the presen- tation of hCG. （3）Leptin probably blocked the inhibition of neuropeptide Y on E2 secretion, and this may indicate that there were some coordination between leptin and neuropeptid Y on the level of ovarian function.