Progesterone and estradiol regulate sperm hyperactivation and in vitro fertilization success in mice
Miyu Fujikura1, Masakatsu Fujinoki1
1Research Laboratory of Laboratory Animals, Research Center for Laboratory Animals, Comprehensive Research Facilities for Advanced Medical Science, School of Medicine, Dokkyo Medical University, Tochigi 321-0293, Japan.
Abstract:
Progesterone (P) and 17β-estradiol (Eβ) form the well-known hormone pair that regulates sperm capacitation. Here, we examined the regulatory effects of P and Eβ on sperm hyperactivation in mice and evaluated the in vitro fertilization (IVF) success. Although P enhanced hyperactivation, Eβ dose-dependently suppressed the P-enhanced hyperactivation. Moreover, P increased IVF success, whereas Eβ suppressed the P-induced increase in IVF success in a dose-dependent manner. Thus, P and Eβ competitively regulate hyperactivation and IVF success in mice. Since P and Eβ concentrations generally change during the estrous cycle, sperm are speculated to capacitate in response to the oviductal environment and fertilize the oocyte.
