EFFECTS OF CORTISOL ON THE AMOUNTS OF ESTRADIOL-17-BETA AND PROGESTERONE SECRETED AND THE NUMBER OF LUTEINIZING-HORMONE RECEPTORS IN CULTURED BOVINE GRANULOSA-CELLS

The direct effects of cortisol upon the amounts of estradiol-17beta an d progesterone secreted, and the number of luteinizing hormone (LH) re ceptors in cultured bovine granulosa cells were examined. Granulosa ce lls from small bovine follicles (diameter 3-7 mm) were successfully cu ltivated in a 1:1 mixture of Dulbecco's modified Eagle's medium and Ha m's F-12 nutrient medium containing 10% fetal calf serum for the first day and subsequently incubated with follicle stimulating hormone and testosterone in serum-free medium for up to 8 days. The cells increase d their output of both estradiol and progesterone during 9 days of cul ture. The addition of cortisol in the range 0.1 - 10 muM did not signi ficantly change the total DNA content of the granulosa cells. Cortisol treatment caused a significant decrease in the amount of estradiol-17 beta secreted by granulosa cells (P < 0.05). Cortisol also significant ly decreased the number of LH receptors in the cultured granulosa cell s in a dose-dependent manner (P < 0.05). In contrast. cortisol tended to increase progesterone production by granulosa cells. These results demonstrate the direct inhibitory effect of cortisol on follicular sec retion of estradiol-17beta and LH receptor content. This observation i s consistent with the hypothesis that cortisol released by stress may directly inhibit the functional maturation of the bovine follicles.