The effects of different concentrations of sodium selenite on the in vitro maturation of preantral follicles in serum-free and serum supplemented media.

PURPOSE: This study was to investigate the effect of sodium selenite (SS) on in vitro maturation of mouse preantral follicles.
METHODS: The isolated preantral follicles were cultured in TCM 199 medium supplemented with different concentrations (0, 5, 10, 15 ng/ml) of SS and 3 mg/ml bovine serum albumin (BSA) or 5% Fetal Bovine Serum (FBS). The ovulation was induced by addition of 1.5 IU/ml human chorionic gonadotropin. The size and development of follicles and oocytes were assessed by calibrated eyepiece.
RESULTS: The survival rates of follicles in FBS supplemented groups containing 5 and 10 ng/ml SS (88.23%, 90.83%) were higher than other groups (P < 0.05 and P < 0.001 respectively). The mean diameter of follicles (199.84 +/- 15.58 microm) and the percentage of MII oocyte (33.08%) were higher in FBS supplemented group containing 10 ng/ml SS (P < 0.001).
CONCLUSION: The sodium selenite and FBS improve the in vitro growth and maturation of mouse preantral follicles.