Effects of epidermal growth factor, transforming growth factor α and androstenedione on follicular growth and aromatization in culture

The effects of epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and androstenedione on follicular growth and oestradiol production were studied in cultured mouse preantral follicles. Cultured follicles in the control group showed growth and steroidogenic capacities up to the antral follicle stage at day 4 of culture. However, many of these follicles failed to resume their growth during the culture. Increasing concentrations of EGF and TGF alpha decreased the number of follicles reaching the large antral stage at day 4 of culture. All treatments with EGF, TGF alpha and androstenedione caused significant inhibitions in both follicular growth and oestradiol production, regardless of the dose used (1-20 ng/ml). Moreover, no synergistic effect between androstenedione and either of the two growth factors was observed. These results suggest that EGF, TGF alpha and/or androstenedione may play important roles in the modulation of gonadotrophin-controlled ovarian function. The effects observed in this study suggest that the aberration in the regulation of these growth factors may result in the creation and maintenance of certain ovarian disorders, such as the polycystic ovarian disease.