In Vitro Maturation of Oocytes Derived from Preovulatory Follicles Produced In Vitro After Exposure to Hydrostatic Pressure

Rashidi Z *, Azadbakht M , Amini A ,


Objective: In vitro maturation (IVM) of mammalian oocytes has become an efficient method to produce mature oocytes in order to use in assisted reproductive techniques. Induction of ovulation to obtain mature oocytes for IVF has become a routine procedure in many infertility clinics. Some women however rather fail to respond to the hormonal stimulation or are at risk of ovarian hyperstimulation. In vitro maturation of oocytes offers an alternative to obtain mature oocytes in these cases. Hydrostatic pressure as a physical force is effective in reproduction system and there is an increase in intrafollicular pressure between 15-20 mmHg in the ovulating follicle during the late stage of the ovulatory process. In this study we examined the effect of hydrostatic pressure on in vitro maturation of oocyte derived from preovulatory follicle produced in vitro. Material and Methods: Preantral follicles were isolated from 12-14 day-old female NMRI mice each follicle cultured individually in micro<font>drop</font>s of MEM-α culture medium supplemented with 5% FBS 100 mIU/ml rFSH (Gonal-f) 10ng/ml recombinant Epidermal Growth Factor under detoxified mineral oil for 12 days. On day 12 follicles with diameter ≥500 µm and good quality were induced using 7.5 IU/ml human chorionic gonadotropin for oocyte maturation. At the start of in vitro maturation follicles divided into two groups control and experiment. In experiment group follicles were subjected to 20 mmHg hydrostatic pressures in pressure chamber for 30 min. Then follicles from two groups were cultured for assessed in vitro maturation of oocyte. Results: Our results showed that after 24 h the percentage of metaphase (MII) oocyte increased in hydrostatic pressure treated follicles (16%) compared to control (9%)(p