EVALUATION OF NUCLEAR MATURATION AND APOPTOSIS OF BOVINE OOCYTE RECOVERED BY FOLLICULAR ASPIRATION WITH DIMETHYLTHIOUREA (DMTU)

CRUZANS, PR.; MARURI, A.; TELLO, MF.; LORENZO, MS.; LOMBARDO, DM.

Ciudad Autónoma de Buenos Aires

Jornada; IV Jornadas Internacionales del Instituto de Investigación y Tecnología en Reproducción Animal; 2014

Instituto de Investigación y Tecnología en Reproducción Animal

In vitro maturation (IVM) allows use ovaries as a source of immature oocytes. During transport to the laboratory, the ovaries become ischemic conditions by occlusion of blood flow and reduce the oxygen supply. Th e reoxygenation of ischemic tissues generates reactive oxygen species (ROS) that are toxic to the cells. Th e aim of this study was to evaluate the eff ect of adding an antioxidant, dimethylthiourea (DMTU), in the recovery medium of cumulus-oocyte complexes (COC) obtained from bovine ovaries by follicular aspiration on the nuclear maturation and oocyte apoptosis. COCs were obtained through puncture of ovarian follicles slaughter cattle with collection medium TCM-199 with or without the addition of 2 or 20mM DMTU give 3 groups: Control (TCM-199 without antioxidant), DMTU 2mM and DMTU 20mM which were matured for 22 h. After IVM oocytes were denuded to determine the nuclear stage (Hoechst 33342 staining) and apoptosis. Annexin V staining - IP were used to determine early apotosis and TUNEL assay to determine late apoptosis. There were no signifi cant diff erences in the percentage of meiotic maturation between control (79.9%, n=343) and addition of 2 or 20mM DMTU in the collection medium (77.3%, n=291; 77.7%, n=220, respectively). Regarding apoptosis, there were no signifi cant diff erences between the percentages of Annexin positive oocytes between the control (0%, n=205), 2mM DMTU (1.6%, n=118) and 20mM DMTU (0 %, n=109) or the percentage of TUNEL positive between the control group (1.1%, n=177), 2mM DMTU (0.6%, n=164) and 20mM DMTU (1,7%, n=117). Th erefore, the addition of DMTU in the collection medium of bovine oocyte recovered by follicular aspiration at the two concentrations used not produces differences in the nuclear maturation or the percentage of early or late apoptosis in vitro matured oocytes from control. Future research will evaluate whether adding DMTU in the collection medium modulates ROS production and cytoplasmic oocyte maturation.