INPA   24560
UNIDAD EJECUTORA DE INVESTIGACIONES EN PRODUCCION ANIMAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Hydrogen peroxide and superoxide anion participation in bovine oocyte maturation in vitro
Autor/es:
S. MORADO; P. CETICA; M. BECONI; G. DALVIT
Lugar:
París
Reunión:
Congreso; Ovarian Club III. The inverse pyramid: regulating follicle number and oocyte quality; 2013
Institución organizadora:
Ovarian Club
Resumen:
In cattle, embryo in vitro production is still unsatisfactory. The deficient embryonic development could be due to a poor oocyte quality. The role of reactive oxygen species (ROS), such as H2O2 and O2-, in in vitro maturation and fertilization remains controversial. Therefore, the aim of this work was to determine the effect of H2O2 and O2- enzymatic generators and scavengers on ROS production and meiotic maturation rate of bovine oocytes. Cumulus-oocyte complexes were recovered by aspiration of antral follicles from slaughtered cow ovaries and cultured for 22h at 39ºC, 5% CO2 in humidified air in medium 199 (control) with or without xanthine + xanthine oxidase (H2O2 generating system), xanthine + xanthine oxidase + catalase (O2- generating system), catalase (H2O2 scavenger) or catalase + superoxide dismutase (O2- scavenger). Meiotic maturation was determined by the presence of metaphase II using Hoechst 33342, whereas ROS production was determined in denuded oocytes at 0, 6, 12, 18 and 22h by 2?,7?-dichlorodihydrofluoresceindiacetate assay. A significant increase in ROS levels was detected at 6 and 18h in oocytes cultured in the presence of xanthine + xanthine oxidase + catalase respect to the control (p<0.05). Oocytes cultured in the presence of both generators and scavengers of H2O2 and O2- presented a significantly lower meiotic maturation rate compared with those matured in control medium (p<0.05). These results suggest that, although an excess of H2O2 and O2- could be detrimental for oocyte quality, at physiological concentrations they would be necessary for the maturation process.