Morphologic, ultrastructural, and biochemical identification of apoptosis in vitrified-warmed mouse ovarian tissue

ObjectiveTo evaluate the incidence of apoptosis after vitrification warming of mouse ovaries.DesignExperimental study.SettingUniversity-based research laboratory.Animal(s)Twelve- to 14-day-old National Medical Research Institute female mice.Intervention(s)Vitrification of mouse ovaries using ethylene glycol.Main outcome measure(s)Follicle viability assessment by trypan blue testing, morphologic examination by hematoxylin–eosin staining and transmission electron microscopy, apoptosis assessment using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling method and DNA laddering technique.Result(s)No statistically significant difference in follicle viability was observed between vitrified and nonvitrified ovaries. On transmission electron microscopy, vitrified ovaries showed a well-preserved ultrastructure. No sign of apoptosis was observed morphologically or by transferase-mediated deoxyuridine triphosphate nick end-labeling technique in either fresh or vitrified-warmed mouse ovaries. Despite the presence of a laddering pattern of DNA in control induced thymic tissue, no similar pattern was observed in fresh or vitrified-warmed ovaries.Conclusion(s)The data suggest that the vitrification technique does not induce apoptosis in mouse ovarian tissue investigated just after warming.