ObjectiveTo determine if the cryoprotectant solution supplementation with Vitamin C can improve the protective effect of human ovarian tissue cryopreservation by anti-apoptosis. MethodsHuman ovarian cortical tissues were collected from nine patients treated between March 2012 and April 2013. The cortical tissue pieces obtained from each patient were divided into two groups:control (conventional slow freezing) and trial group (slow freezing supplementation with Vitamin C). The preservation effects in the two groups were compared by histology using light microscope and apoptosis assessed by TUNEL assay. ResultsThe proportion of morphologically normal primordial follicles in the trial group was higher than that in the control group (P<0.05). The proportion of apoptotic primordial follicles and stromal cells in the trial group was lower than that in the control group (P<0.05). ConclusionCryoprotectant solutions supplementation with Vitamin C can improve the preservation of primordial follicles and stromal cells. It might be a method worth to try in order to improve the protective effect of human ovarian tissue cryopreservation by inhibiting of apoptosis.
ObjectiveTo compare the effect of cryoprotective vitrification agent with different concentrations on protecting human ovarian tissue. MethodsHuman ovarian biopsy tissues were obtained from nine patients between August 2013 and May 2014. The cortical tissue pieces obtained from each patient were cryopreserved using direct cover vitrification (DCV) with two different concentrations. The vitrification solutions were divided into two groups: high concentration [15% (V/V) dimethyl sulphoxide (DMSO)+15% (V/V) ethylene glycol (EG)+0.5 mol/L sucrose] and low concentration group (12% DMSO+12% EG+0.5 mol/L sucrose). The preservation effects in the two different concentration groups were compared by histologic evaluation using light microscope and apoptosis assessed by terminal dexoynucleotidyl transferase-mediated nick end labeling staining. ResultsThere was no significant difference in the proportion of morphologically normal primordial follicles between high concentration group and low concentration group (P ＞ 0.05) . The proportion of apoptotic primordial follicles in the low concentration group was 29.7% (58/195) , and was 42.1% (69/164) in the high concentration group, with a significant difference between the two groups (P ＜ 0.05) . The proportion of apoptotic stromal cells in the low and high concentration group was 30.2% (162/537) and 41.9% (206/492) respectively with a significant difference (P ＜ 0.05) . ConclusionsVitrification solutions with lower concentration can improve the preservation of the primordial follicles and stromal cells in human ovarian tissue. It is a method worth trying in order to improve the protective effect of vitrification by decreasing the toxicity of vitrification solutions.