Ovarian Modulators of 11β-Hydroxysteroid Dehydrogenase (11βHSD) Activity in Follicular Fluid from Bovine and Porcine Large Antral Follicles and Spontaneous Ovarian Cysts1
Biology of Reproduction
In the ovary, cortisol is oxidized to cortisone by 11␤-hydroxysteroid dehydrogenase (11␤HSD). The present study investigated whether follicular fluid (FF) from large antral follicles and spontaneous ovarian cysts, isolated from bovine and porcine ovaries, contained modulators of 11␤HSD activity. Whereas FF from antral follicles had no significant effect over 1 h on NADP ؉ -dependent 11␤HSD activity in rat kidney homogenates, enzyme activity was inhibited by FF from bovine and porcine ovarian
... ts (80.5% ؎ 2.3% and 72.8% ؎ 3.4% of control, respectively). Following C18 reverse-phase chromatography, the hydrophilic fractions of FF from bovine and porcine antral follicles stimulated NADP ؉ -dependent 11␤HSD activities (111.5% ؎ 21.6% and 55.2% ؎ 5.7% respectively). Hydrophobic compounds inhibited NADP ؉ -dependent cortisol oxidation by 58.2% ؎ 5.1% (bovine) and 45.7% ؎ 2.0% (porcine). In both species, FF from ovarian cysts appeared to contain less of the hydrophilic stimuli to 11␤HSD activity and more of the hydrophobic inhibitors. The FF from antral follicles and ovarian cysts, and the C18 fractions thereof, had no significant effect on NAD ؉ -dependent cortisol oxidation. The ovarian modulators of NADP ؉ -dependent 11␤HSD activities did not coelute with cortisol, cortisone, estradiol, testosterone, progesterone, pregnenolone, and cholesterol. However, the 11␤HSD stimuli in porcine FF from both antral follicles and cysts coeluted with prostaglandin (PG) E 2 and PGF 2␣ . We conclude that large antral follicles and spontaneous ovarian cysts, in both the cow and the pig, contain ovarian modulators of the NADP ؉ -dependent 11␤HSD activity. Moreover, FF from spontaneous ovarian cysts, because of decreased content of the 11␤HSD stimulus accompanied by increased content of the 11␤HSD inhibitors, exerts a net inhibitory effect on 11␤HSD activity. cortisol, follicle, ovulation, ovulatory cycle 1 Supported by a grant from Freemedic plc (London, U.K.), BBSRC project grant 48/S15850, and MRC Studentship G69/1756.