Abstract
BACKGROUND: Low cryotolerance in oocytes and embryos is frequently associated with
lipid accumulation in the cytoplasm. OBJECTIVE: This study aimed to evaluate the effect of
cyclodextrin used as a cholesterol loader to change cytoplasmic cholesterol content of embryos and
raise their tolerance to cryopreservation. METHODS: In the first experiment compact morulae-early
blastocysts were exposed to CLC (0.11 mM and 0.23 mM cholesterol) for 1 hour. In the second
experiment, embryos were exposed to CLC (0.11 mM and 0.23 mM cholesterol) and then vitrified.
RESULT: Using both concentrations, cytoplasmic cholesterol content was increased. Vitrified groups
demonstrated a lower capacity for embryonic development (in vitro and in vivo) compared to the
control groups. Nevertheless, live young were obtained in all groups. CONCLUSIONS: In
conclusion, we have demonstrated the feasibility of using cyclodextrin as a carrier for cholesterol into
rabbit embryo cytoplasm, although further studies are required to clarify the usefulness of CLC use in
embryo cryopreservation
