EFFECT OF ANDROGEN SUBSTRATES ON THE STEROIDOGENIC PATTERN OF CUMULUSCELLS - CORRELATION WITH CUMULUS CULTURE MORPHOLOGY

Background: In previous studies, higher progesterone secretion was obs erved in mature versus immature cumulus-oocyte complexes. In mature cu mulus mass that become homogeneously spread in culture (type C/D) prog esterone secretion was higher than in partially (type B) or totally (t ype A) aggregated morphology. In sharp contrast, estradiol-17 beta sec retion was significantly higher in type A than type C/D cumulus. Purpo se: Our purpose was to assess whether the decreased estradiol-17 beta level in type C/D cumulus culture is caused by deficiency of substrate s. Methods: The different cumulus types were incubated with or without 10(-7) M dehydroepiandrosterone, 4-androstane-3, 17-dione, or testost erone. The levels of estradiol-17 beta, testosterone, and progesterone , were measured after 24 hr of culture. Results: The addition of dehyd roepiandrosterone or 4-androstane-3,17-dione significantly increased t he estradiol-17 beta levels in all types of cumulus cells, whereas the addition of testosterone was less effective. In all types of cumulus cells the testosterone levels increased significantly on adding these androgen substrates. In the type C/D cumulus, the testosterone increas ed to lower levels compared to type A cumulus cells. In the presence o f these androgens progesterone secretion is significantly reduced in t ype A cumulus cells. In type C/D cumulus cells, however; progesterone levels were significantly higher than in type A. The estradiol-17 beta /testosterone and progesterone/estradiol-17 beta ratios, which partial ly resemble the degree of aromatase activity and the degree of selecti vity for progesterone secretion, respectively, were higher in type C/D than in type A cumulus cells. Conclusions: In type C/D cumulus the si gnificant increase in estradiol-17 beta secretion in the presence of v arious androgens suggests that, under basal conditions, androgen is le ss available for estradiol-17 beta biosynthesis compared to type A cum ulus. Furthermore, the higher progesterone secretion in type C/D cumul us may suggest that the follicles yielding type C/D cumulus cells are more mature than the follicles yielding type A cumulus.