Mouse Ovarian Tissue Vitrification: effects of exposure time to cryoprotective agent

Abstract

Objective The objective of this study was to compare the survival rate and growth rate of iso-lated preantral follicles from vitrified/warmed mouse ovarian tissues with different exposure times to Vitrification Solution 2 (V2).Methods Mouse ovaries were divided into a control and four experimental groups. All four experi-mental groups were vitrified and warmed with exposure times to V2 solution for 3, 5, 10 and 15-min-utes. Preantral follicles were mechanically isolated from the vitrified/warmed ovarian tissue and individually cultured in vitro in 10-μL drops of culture medium under paraffin oil. Follicle diameter was measured every two days for 12 days. Primary outcome measurements were the survival rate and growth rate of the isolated preantral follicles.Results Preantral follicles from vitrified/warmed ovarian tissues that were exposed to V2 solution for five and ten-minutes had the highest survival rates (73.20% and 72.17%, respectively). The three and fifteen-minute exposure groups had survival rates of only 65.37% and 56.55%, respec-tively. There was no difference in the mean diameter of the follicles during the first eight days. On day ten, the mean follicular diameter of the fifteen-minute group was lower than the control group (p<0.001). On day 12, diameters of the three and fifteen-minute groups were lower than the control group (p=0.005 and p<0.001, respectively). The preantral follicles from the five and ten-minute groups had growth rates comparable to the control groupconclusion Exposure of mouse ovarian tissues to V2 solution for five and ten-minutes yields the highest survival rate and growth rate of preantral follicles, while both longer and shorter exposures adversely affects the survival and subsequent development of preantral follicles.