Abstract
This investigation was carried out to asertain whether corticosteroidogenesis in the follicular tissues is required for gonadotropin-induced ovulation of the Oryzias oocyte. A specific inhibitor (SU- 4885) of 11β-hydroxylase resulted in inhibition of gonadt tropin-induced ovulation but did not affect ovulation induced by cortisol. Furthermore, it was shown that prior exposure of oocytes to metopirone reduced the response of the oocytes to gonadotropin but ovulation induced by cortisol was not affected by the prior treatment. These results suggest that an inhibition of corticosteroidogenesis prevents ovulation and prior treatment 2 hours in advance is the period necessary for corticosteroidogenesis in the follicular tissues in Oryzias oocyte.
