Induction of multiple ovulation via modulation of angiotensin II receptors in in vitro ovarian follicle culture models.

ABSTRACT

In vitro culture of ovarian follicles is a promising bioengineering technique for retrieving fertilizable oocytes from preserved ovarian tissues of cancer survivors. However, current in vitro follicle culture techniques are labour-intensive and of low efficiency, as only single follicle culture (SFC) has been possible to date. The present study investigated the feasibility of multifollicular cluster culture (MFCC) system using angiotensin II receptor (ATII-Rc) analogues. Ovarian pre-antral follicles isolated from 2-week-old C57BL6 mice were cultured with ATII-Rc agonist or antagonist and their maturation outcomes were compared with control group. When single follicles were cultured, the ovulation and maturation rates were similar in all three groups. When three-follicle clusters were cultured, up to three follicles were ovulated in the ATII-Rc agonist group while none or one follicle ovulated in control or antagonist groups (p < 0.0001). Significantly higher numbers of mature oocytes were obtained in the agonist group (three-follicle 28.2 ± 4.9 vs. SFC 11.0 ± 1.3, per 25 cultured droplets) (p < 0.0001), and the development of each fertilized oocytes was comparable to those from SFC. It is therefore concluded that this novel MFCC system can significantly improve the efficiency of in vitro mature oocyte retrieval via ATII-Rc modulation. Copyright © 2016 John Wiley & Sons, Ltd.