Non-genomic action of estradiol and progesterone on cytosolic calcium concentrations in primary cultures of human granulosa-lutein cells.
BACKGROUND
The present study examined whether the sex steroids, estradiol and progesterone, could alter cytoplasmic calcium concentrations ([Ca(2+)](cyt)) in human granulosa-lutein cells.


METHODS
Human granulosa cells were obtained at the time of oocyte retrieval for IVF and cultured for 3-7 days. Cells were loaded with Fura-2 AM and changes in [Ca(2+)](cyt) of single cells were studied using a dynamic digital Ca(2+) imaging system.


RESULTS
Both estradiol and progesterone stimulated elevations of [Ca(2+)](cyt) in Ca(2+)-containing medium within seconds of exposure of the granulosa-lutein cells to the steroid, but only estradiol caused an increase in [Ca(2+)](cyt) in Ca(2+)-free medium. Both ICI-182780 and RU 486 stimulated [Ca(2+)](cyt) increases and inhibited the effects of estradiol and progesterone, respectively. Tamoxifen also induced transient increases in [Ca(2+)](cyt) concentrations but inhibited the effects of both estradiol and progesterone. The inhibitory effects of tamoxifen, ICI-182780 and RU 4486 on [Ca(2+)](cyt) responses to estradiol and progesterone could be reversed with higher concentrations of estradiol and progesterone, respectively. The [Ca(2+)](cyt) effects induced with tamoxifen could not be eliminated by prior treatment with RU 486 or ICI-182780.


CONCLUSIONS
These results provide strong evidence that both estradiol and progesterone as well as the steroid antagonists, tamoxifen, RU 486 and ICI-182780, can act on human granulosa-lutein cells through a non-genomic mechanism.
Younglai
E V
EV
Department of Obstetrics and Gynecology, Reproductive Biology Division, McMaster University, Health Sciences Centre, Hamilton, Ontario, Canada. younglai@mcmaster.ca
Wu
Y J
YJ
Kwan
T K
TK
Kwan
C-Y
CY
D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D000077267:Fulvestrant; D006727:Hormone Antagonists / Q000494:pharmacology; D006801:Humans; D008184:Luteal Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D015735:Mifepristone / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology*
D004965:Estrogen Antagonists; D006727:Hormone Antagonists; D000077267:Fulvestrant; D015735:Mifepristone; D011374:Progesterone; D004958:Estradiol; D002118:Calcium