ROLE OF GONADOTROPINS AND OVARIAN-STEROIDS IN THE DEVELOPMENT OF MOUSE FOLLICLES IN-VITRO

A whole follicle culture system has been used to investigate the actio ns of gonadotrophic hormones, oestrogen and progesterone in the regula tion of follicular development and steroidogenesis, Recombinant human FSH was required for the growth of preantral follicles and for Graafia n morphogenesis, whereas recombinant LH was ineffective. While pure FS H was sufficient for growth and morphogenesis, production of oestrogen was greater when androstenedione or LH was present in combination wit h FSH, confirming that there is a two-cell mechanism for oestradiol pr oduction in the mouse follicle. When an antiserum to oestrogen or to p rogesterone or an oestrogen receptor antagonist were added to the cult ure medium, there was no significant effect on either follicular growt h or oestradiol production. Thus, physiological concentrations of oest radiol are not needed for follicle development, although a role cannot be completely ruled out. In conclusion, the obligatory role of FSH wa s demonstrated. It appears to be sufficient for follicle development e ven in the absence of LH, and the paracrine or autocrine effects of oe stradiol and progesterone, if any, appear to be minor in the mouse ova ry.