Relation between bovine oocyte in vitro maturation and modulation of nitric oxide production

SERGIO MORADO; PABLO CETICA; DANIELA MONTAGNA; MARTHA BECONI; GABRIEL DALVIT

San Juan

Jornada; II Reunión Conjunta de Sociedades de Biología de la República Argentina; 2011

Sociedades Argentinas de Biología

Nitric oxide is a ubiquitous free radical that plays a role in oocyte activation and maturation, embryonic development and implantation. The aim of this work was to determine NO participation in the production of reactive oxygen species (ROS) and bovine oocyte in vitro maturation. Cumulus-oocyte complexes were recovered by aspiration of antral follicles from ovaries obtained from slaughtered cows and cultured in medium 199 (control), 0,5 mM N-nitro-L-arginine methyl ester (L-NAME), endothelial NO synthase inhibitor, 10 µM sodium nitroprusside or 100 µM detanonoate, NO donors, at 39°C, 5% CO2 in humidified air for 22h. Meiotic maturation was determined by the presence of metaphase II. ROS production was determined in denuded oocytes at 0, 6, 12, 18 and 22h by the ratio between 2?,7?-dichlorodihydrofluorescein diacetate and fluorescein diacetate assays. ROS levels fluctuated during the 22h of maturation, showing a similar pattern with the different treatments. COCs cultured in the presence of NO donors showed a significantly lower maturation percentage (20% vs. 80%; p