The effect of high glucose concentration on the quality of oocytes derived from different growth stages of follicles

This study examined the effect of hyperglycemic culture conditions on the development of oocytes derived from early antral follicles (EAFs). Oocyte—granulosa cell complexes (OGCs) derived from EAFs were cultured for 12 days in medium containing 5.56 mM or 11 mM glucose, and the rate of antrum formation and glucose consumption by the OGCs, and the characteristics of the oocytes grown in vitro were studied. The results were compared with those obtained from in vivo grown oocytes derived from antral follicles (AFs; 3–5 mm in diameter). In addition, the effect of a high glucose concentration in the maturation medium on the quality of oocytes derived from AFs was examined. The high glucose condition increased the glucose consumption of the OGCs but did not affect antrum formation, oocyte diameter, chromatin configuration, levels of histone 4 K12 acetylation, nuclear maturation, and the developmental ability of oocytes grown in vitro. In contrast, high glucose-maturation medium increased the amount of reactive oxygen species and adversely affected the developmental ability of the oocytes. In conclusion, the results of this study suggest that culture under hyperglycemic conditions is detrimental to oocyte maturation but not for oocyte growth from the EAF stage to the AF stage.