Addition of ascorbate during cryopreservation stimulates subsequent embryo development.
BACKGROUND
Embryo development following cryopreservation is reduced compared with fresh embryos. One of the traumas that cryopreservation imparts on embryos is an increase in oxidative stress. Therefore, this study investigated the effects of the addition of the antioxidant ascorbate to the cryopreservation solutions on subsequent embryo development.


METHODS
Mouse embryos at the 2-cell and blastocyst stages were either slow-frozen or vitrified in solutions containing either no ascorbate or 0.1 or 0.5 mmol/l ascorbate. The effects on the levels of hydrogen peroxide and subsequent embryo development and physiology were assessed.


RESULTS
Addition of ascorbate to the cryopreservation solutions reduced the levels of hydrogen peroxide in embryos. Furthermore, addition of 0.1 mmol/l ascorbate significantly enhanced inner cell mass development in blastocysts. Embryos cryopreserved with ascorbate had significantly lower levels of lactate dehydrogenase leakage, and increased rates of metabolism compared with those cryopreserved in the absence of ascorbate. The benefits of ascorbate were significantly greater in embryos that were slow-frozen compared with those that were vitrified.


CONCLUSIONS
These data indicate that the addition of 0.1 mmol/l ascorbate to the cryopreservation solutions for the mammalian embryo would be of significant value.
D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage*; D001755:Blastocyst / Q000502:physiology; D015925:Cryopreservation / Q000379:methods*; D046508:Culture Techniques; D005314:Embryonic and Fetal Development / Q000187:drug effects*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010084:Oxidation-Reduction; D019289:Pyruvic Acid / Q000378:metabolism; D012996:Solutions; D013997:Time Factors
D012996:Solutions; D019289:Pyruvic Acid; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D005947:Glucose; D001205:Ascorbic Acid