Open AccessThe role of pituitary gonadotropins and intraovarian regulators in follicle development: A mini‐review
Author(s) -
Orisaka Makoto,
Miyazaki Yumiko,
Shirafuji Aya,
Tamamura Chiyo,
Tsuyoshi Hideaki,
Tsang Benjamin K.,
Yoshida Yoshio
Publication year - 2021
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1002/rmb2.12371
Subject(s) - folliculogenesis , antral follicle , medicine , endocrinology , gonadotropin , follicle stimulating hormone , luteinizing hormone , biology , ovarian follicle , follicular phase , microbiology and biotechnology , hormone , embryogenesis , embryo
Background The process of follicle development is tightly regulated by pituitary gonadotropins (follicle‐stimulating hormone [FSH] and luteinizing hormone [LH]) and intraovarian regulators (eg, steroids, growth factors, and cytokines). Methods This review outlines recent findings on the mechanisms of human follicle development, based on the research on animal models such as mice, rats, cows, and sheep. Main findings Phosphatidylinositol 3‐kinase/protein kinase B signaling pathway and anti‐Müllerian hormone are involved in primordial follicle activation during the gonadotropin‐independent phase. The intraovarian regulators, such as androgen, insulin‐like growth factor system, activin, oocyte‐derived factors (growth differentiation factor‐9 and bone morphogenetic protein 15), and gap junction membrane channel protein (connexin), play a central role in the acquisition of FSH dependence in preantral follicles during the gonadotropin‐responsive phase. Antral follicle development can be divided into FSH‐dependent growth and LH‐dependent maturation. The indispensable tetralogy for follicle selection and final maturation of antral follicles involves (a) acquisition of LH dependence, (b) greater capacity for E2 production, (c) activation of the IGF system, and (d) an antiapoptotic follicular microenvironment. Conclusion We reproductive endocrinologists should accumulate further knowledge from animal model studies to develop methods that promote early folliculogenesis and connect to subsequent gonadotropin therapy in infertile women.