AIM AND METHODSThe method of labeled streptavidin biotin was used to study the expression of c-fos in various functional state of rat ovaries and its relationship with the levels of serum estradiol and progesterone.

RESULTS(1) In the mature rat, c-fos expression was found higher in interstitial gland and stroma of proestrous ovaries and lower in estrous ovaries, and was found higher in luteal cells and stroma of pregnant ovaries and lower in diestrous ovaries. There was a positive correlation between the area and optical density of c-fos expression and the levels of serum E2 and P. (2) In the immature rats, c-fos expression was not found in the ovaries containing preantral follicles from DES-treated rats,and was found both in interstitial gland and stroma of the ovaries containing preovulatory follicles from PMSG-treated rats ,and the expression was higher in day 4 luteinized ovaries and lower in day 9 luteinized ovaries from PMSG with hCG treated rats. There also was a positive correlation between the area and optical density of c-fos expression and the levels of serum E2 and P.

CONCLUSIONThe results suggested in rat ovaries and might play an important role in follicles development, ovulation, luteum formation and regression.