Objective: To compare the effects of two cryoprotective agents (DMSO and 1,2-PROH) used at two concentrations (1,5 and 2 M) on the morphology of small ovarian cortex follicles in doe.
Materials and methods: Ovarian cortexes (n=40) were frozen in TCM199+10% FCS medium added to 1.5 or 2 M of DMSO or 1,2-PROH. Two controls were realized (fresh and frozen without cryoprotectant). The equilibration in cryoprotective solutions before freezing, and the elimination of the cryoprotective agents after thawing, was performed step by step. The effects induced by cryopreservation were evaluated by histological examination.
Results: Fresh ovarian tissue showed 68.6% of intact follicles. After freezing, only 1.5 M of 1,2-PROH preserved 48.0% of normal follicles, with no significant difference compared to the fresh control. The proportion of follicles without morphological defect observed after cryopreservation with DMSO was significantly reduced (respectively 28.8 and 34.8% for 1,5 and 2 M of DMSO).
Discussion and conclusions: Our results suggest that 1,2-PROH is a more effective cryoprotectant than DMSO, for the cryopreservation of doe ovarian cortex. These results differ from those that were obtained for other species, credibly because of a higher fragility of the ovarian tissue of the doe. Nevertheless, this species is an interesting animal model which allows rapid results after cryopreserved ovarian tissue graft.