Ascorbic acid effects on in vitro maturation of mouse oocyte with or without cumulus cell

Ascorbic acid has long been associated with fertility. This study was designed to determine the effects of ascorbic acid on in vitro maturation of mouse oocyte with or without cumulus cells. In this study, 508denuded oocytes (DOs) and 527 cumulus–oocyte complexes (COCs) from mice stimulated with pregnant mare’s serum gonadotrophin (PMSG) were incubated for 24 h in medium containing 0, 80, 250 and 750 &#956 M/ml of ascorbic acid prior to in vitro maturation. Maturation rate was compared. A significant decrease in the maturation rate was observed only when the DOs and COCs were exposed to 750 &#956 M/ml of ascorbic acid (P < 0.05). The maturation rate in COCs was significantly higher than DOs in all groups (P < 0.05). These results indicate that exposure ascorbic acid promotes the development of mouse DOs and COCs from germinal vesicle breakdown (GVBD) to metaphase II (MII) and prevents cumulus celldegeneration at certain levels, especially 250 &#956 M/ml of ascorbic acid (P < 0.05). However, further studies on the potential effects of different concentrations of ascorbic acid on oocyte maturation are needed