S. Muttukrishna et al., GONADOTROPIC CONTROL OF SECRETION OF DIMERIC INHIBINS AND ACTIVIN-A BY HUMAN GRANULOSA-LUTEAL CELLS IN-VITRO, Journal of assisted reproduction and genetics, 14(10), 1997, pp. 566-574
Purpose: It is well established that human granulosa cells and luteal
cells express inhibin/activin subunit protein and secrete immunoreacti
ve inhibin. The gonadotropic control of secretion of different molecul
ar forms of inhibin and activin A by granulosa-luteal cells (G-LCs) wa
s investigated using recently developed specific enzyme immunoassays (
ELAs). Methods: Granulosa-luteal cells obtained at IVF egg pickup were
cultured in a serum-free medium at 37 degrees C in a water-saturated
incubator with 5% CO2 for up to 5 days. Experiments with varying conce
ntrations of human FSH, hLH, and hCG were carried out. Results: FSH ra
ised the secretion of inhibin A and pro-alpha C-containing inhibins af
ter 24 and 48 hr in culture, inhibin B was raised after 24 hr and acti
vin A was raised after 48 hr of FSH treatment. LH treatment for 24 hr
stimulated inhibin A, inhibin B, pro-alpha C, and activin A. hCG stimu
lated G-LC secretion of inhibin A after 48 hr mid pro-alpha C after 24
hr Paradoxically, inhibin B secretion was inhibited by 1 and 10 ng/ml
hCG after 48 hr Activin A was stimulated by hCG after 24 and 48 hr of
incubation. G-LC secretion of estradiol and progesterone was also sti
mulated significantly by LH and hCG. Conclusions: Secretion of dimeric
inhibins and activin A is controlled differentially by gonadotropins.