Improving the growth of bovine isolated ovarian secondary follicles with Akt signaling pathway stimulation

In vitro ovarian follicle culture in females at the risk of losing fertility, such premature ovarian failure (POF) and in those subjected to chemo/radio therapy as well as in animals – species at risk of extinction in a promising strategy for fertility preservation. Development of ovarian growing follicles is regulated by the coordinated action of several signaling pathways. The use of some activators or inhibitors of signaling pathways is effective in optimizing the culture conditions of immature follicles. The aim of this study was examining in vitro growth of bovine ovarian secondary stage follicles (> 80 μm) by mimicking the process of in vivo follicular development through of the Akt signaling pathway activator, PS48. Small secondary stage follicles were isolated by enzymatic digestion from slaughter ovaries by collagenase type I and Dnase I, cultured in the presence of BSA (3 mg/ml), FBS (10%), Akt (5µM PS48, first 48 h of culture) or Akt + FBS (5µM PS48, first 48 h of culture + 10% FBS) for ten days and then evaluated for growth rate. The follicular size was significantly increased in all experimental groups during 10 days culture (P<0.05). In all our groups, growth rate/day was higher in initial days of culture, after that follicular growth rate decreased. The highest growth rate was observed in FBS + PS48 group, while the lowest growth rate was detected in PS48. On the other hand, though the FBS supplemented group could increase the growth rate of follicles, its combination with PS48 was more effective . In conclusion, in our study condition the best result in follicular growth, was obtained when follicular culture medium was supplemented with FBS + PS48. In conclusion, in our study condition the best result in follicular growth, was obtained when follicular culture medium was supplemented with FBS + PS48.