Exogenous androstenedione induces formation of follicular cysts and premature luteinization of granulosa cells in the ovary.

OBJECTIVE

To investigate the effects of androstenedione on ovarian follicle development.

DESIGN

Experimental study.

SETTING

University research laboratory.

ANIMAL(S): Female Wistar-Imamichi rats and BDF1 mice.

INTERVENTION(S): Rats were injected with androstenedione. Ovarian follicles of mice were cultured in the presence of androstenedione.

MAIN OUTCOME MEASURE(S): Ovarian morphology; ovarian cell types undergoing apoptosis; ovarian expression of cytochrome P450 aromatase (P450arom), cytochrome P450 side-chain cleavage (P450scc), and cyclin-dependent kinase inhibitor p27(kip1); serum levels of T, E(2), and P in rats; and ultrastructure of granulosa cells from cultured follicles of mice.

RESULT(S): In androstenedione-treated rat ovaries, follicular cysts were formed, and apoptotic cells were found in the inner part of granulosa cell layers of antral follicles. Androstenedione administration down-regulated expression of P450arom but up-regulated expression of P450scc and p27(Kip1) in the granulosa cells of antral follicles. Serum T levels were significantly increased in androstenedione-treated rats. In mouse follicles exposed to androstenedione, the granulosa cells contained abundant lipid droplets and mitochondria with complex tubular cristae.

CONCLUSION(S): Excess androgen enhances apoptosis in the inner part of granulosa cell layers of antral follicles, resulting in the formation of follicular cysts. It is also demonstrated that androgen stimulates premature luteinization of granulosa cells.