The protective effect on ovarian follicles of tissue fragmantation and i̇n vitro culture i̇ncluded maturation activators after vitrification of rat ovaries

In primary ovarian failure cases, Donnez et al. (2004) reported that ovarian tissue transplantation applied to patients with ovarian dysfunction after chemotherapy and radiotherapy treatments restored fertility and endocrine functions. Among the various intracellular signaling systems, the importance of the phosphatidylinositol-3-kinase (PI3K) - Akt - Forkhead box O3 (FOXO3) pathway in primordial follicle activation has been demonstrated by transgenic animal studies. To activate and use preovulatory cells to collect oocytes from POI patients; Phosphatase and tensin homologous (PTEN) enzyme inhibitors and phosphatidylinositol-3 kinase activators have been used to activate the AKT pathway in dormant follicules of rodent and human ovarian tissues. Studies have suggested that ovarian tissue fragmentation may interfere with the ovarian-Hippo signal pathway and also lead to follicule growth. These two methods in the treatment of infertility in POI patients have been combined with a different approach called in vitro activation (IVA). After ovariectomy, follicules were activated in vitro with using AKT stimulators, followed by live birth after ovarian tissue autotransplantation. This study was designed based on the hypothesis that cultivation of ovarian tissues frozen with vitrification method before autotransplantation under the kidney capsule that were fragmented and/or activated with PI3-kinase activator will increase the follicule activation'. Autotransplantation was performed under the kidney capsule of the same subject by dividing the ovarian tissues that were vitrified and dissolved in unilateral ovariectomy by dividing them into two or splitting them into small pieces and/or culture in the medium containing PI3-kinase activator. After ototransplantation, the histomorphological evaluation of ovarian tissue was performed and the effect of fragmentation and/or molecular activator on follicular activation was evaluated. Tissue fragmentation and/or molecular activator application were found to not a different affect for follicular protection after autotransplantation but increased ovarian follicles in the early stage of development. Key words: Ovarian tissue vitrification, Phosphatidylinositol-3-kinase, Tissue fragmantation