Effects of Estradiol on the Paracrine Regulator Expression of In Vitro Maturated Murine Ovarian Follicles

The preservation of female germ cells is important in the individuals with ovarian dysfunction and failure. For this purpose, ovarian follicle in vitro maturation (OFIVM) is an important technology for the retrieval of mature oocytes. In the in vivo follicular development, paracrine factors such as angiotensin (AT) and anti-Müllerian hormone (AMH) play important roles. We attempted to add estrogen during the OFIVM and to assess their expression on the follicular cells. The ovaries and pre-antral follicles were collected from 13-day C57BL/6 mice and cultured in vitro with estradiol (E₂) treatment for up to two weeks. In the whole ovaries, the expression of AT II was decreased and the expression of AMH was similar between control and E₂-treated ovaries after in vitro culture. Although there was no difference in the survival, ovulation, maturation and fertilization rates between control and E₂-treated groups, the expression of AT II in the follicular cells was down-regulated after E₂ treatment at mRNA level, and AMH showed similar expression. In conclusion, adding E₂ in OFIVM may regulate paracrine factors and their receptors that are related to follicular development. Further investigations are necessary to elucidate the roles of various sex hormones in the regulation of AT and AMH expression during the OFIVM.