Steroidogenesis during postnatal development in the mouse ovary

Publisher Website
Google Scholar
Abstract
In the mouse, follicular formation and development is largely postnatal. Changes in ovarian steroidogenesis during early postnatal life are likely, therefore, to reflect changes in follicular activity during early folliculogenesis. In this study, basal progesterone and androstenedione production and responsiveness to gonadotrophins, dibutyryl cyclic AMP (dbcAMP) and 22R-hydroxycholesterol have been measured following short-term in-vitro incubations of ovaries from mice aged 1, 3, 5, 7, 10 or 15 days. On the day of birth (day 1), basal and gonadotrophin-stimulated progesterone and androstenedione production were undectectable although a response to dbcAMP and a low level of cholesterol side-chain cleavage (CSCC) activity (measured using 22R-hydroxycholesterol) were present. On day 3 progesterone and androstenedione production were undetectable under all conditions. On day 5 only a low level of CSCC activity was detectable but on day 7 there was an increase in ovarian steroid production. Basal progesterone and androstenedione were detectable and LH, but not FSH, increased the production of both steroids. These changes were associated with a marked increase of more than 80-fold in CSCC activity. Basal steroid output increased from days 7 to 15 and LH continued to stimulate progesterone accumulation although no effect on androstenedione was seen. Addition of FSH had no effect on steroidogenesis on day 10 but significantly increased progesterone production on day 15. Ovaries from the mice used in these studies contained primordial follicles and stromal tissue on day 1. By day 5 primary and secondary follicles were present and the major increase in steroid production between days 5 and 7 was associated with an increase in secondary follicles and increased differentiation of the thecal tissue. These results show that there is a major increase in ovarian steroidogenesis at day 7 in the mouse and suggest that during folliculogenesis significant gonadotrophin-sensitive steroidogenesis may first be seen in the thecal tissue of the secondary follicle. Journal of Endocrinology (1991) 130, 101–106

This publication has 0 references indexed in Scilit: