The effect of testosterone on the maturation and developmental capacity of murine oocytes in vitro.

A dose-dependent inhibition of meiotic maturation and embryonic development was observed in both cumulus-enclosed and cumulus-denuded murine oocytes following incubation in the presence of 10, 20, 40, 60 and 80 microM testosterone for 18 h in vitro. Maturation to metaphase II was enhanced in cumulus-enclosed oocytes following maturation in the presence of human pre-ovulatory mural granulosa cells. However, maturation of cumulus-denuded oocytes was enhanced only when oocytes were cultured on a monolayer of human polycystic ovarian granulosa cells. The presence of cumulus cells had a significantly positive effect on both oocyte maturation (P = 0.002) and embryonic development (P < 0.001). In addition, the presence of follicular cells during maturation improved the number of fertilized oocytes reaching the blastocyst stage. These data indicate that the exposure of immature murine oocytes to testosterone during maturation significantly reduces their ability to mature and undergo normal embryonic development.