Involvement of gonadotropins in the induction of hypertrophy-hyperplasia in the interstitial tissues of ovaries in neonatally diethylstilbestrol-treated mice.

Neonatally diethylstilbestrol (DES) treatment causes hypertrophy-hyperplasia in the interstitial tissue of mouse ovaries. To understand the induction mechanism of the hypertrophy, mRNA expression involved in steroidogenesis in the ovary of neonatally DES-treated mice was examined. The expression of StAR and Cyp11a1 was significantly reduced while Cyp19 and Sf-1 were stimulated in the ovary of neonatally DES-treated 3-month-old mice. Expression of those genes was not different between DES- and oil-treated mice after the gonadotropins treatment. Lhb in the pituitary of 3-month-old neonatally DES-treated mice was significantly decreased. Finally, ovaries from DES-treated mice transplanted to neonatally oil-treated hosts had developing follicles at several stages and corpora lutea, whereas grafted ovaries from neonatally oil-treated mice in 3-month-old neonatally DES-treated hosts showed lipid accumulation in the interstitial tissue. Thus, hypertrophy and accumulation of lipid droplets in interstitial cells of neonatally DES-treated mice is caused by impaired steroidogenesis due to the alterations of gonadotropins levels.