Efecto de la dimetiltiourea sobre la maduración nuclear y la apoptosis de ovocitos porcinos

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

Buenos Aires

Jornada; IV jornadas internacionales del Instituto de Investigación y Tecnología en Reproducción Animal - INITRA; 2014

INITRA

A balanced redox environment is significant for oocyte quality. An increase in the productionof oxygen reactive species affects oocyte viability.The use of antioxidant during the collection of cumulus oocyte complexes (COCs) it is not reported in porcine. The aim of this study was evaluate the effect of dimethylthiourea (DMTU)on in vitro maturation (IVM) and early and late apoptosis of porcine oocytes.COCs were collected by follicular aspiration from slaughterhouse ovaries. In the control group the collection medium used was TCM-199 and the washing medium was TCM -199supplemented with 10% porcine follicular fluid and penicillin streptomycin. In treatments 2mM and 20mMof DMTU was added to both media. Oocyte completely surrounded by cumulus cells were selected to mature in vitro.The determinations were performed after 44-48 h of IVM.Oocytes were denuded, fixed and stained with Hoechst 33342for the evaluation of IVM rate; oocytes with metaphase II nuclear configuration were considered mature.Early apoptosis was evaluated in fresh and denuded oocytes by Annexin V- propidium iodide (Invitrogen ®). Late apoptosis was measured in fixed and denuded oocytes by TUNEL assay(In Situ Cell Death Detection Kit Roche®). Statistical analysis was performed with Infostat software(p< 0. 05). There were nostatistically significant differences in nuclear maturation rates (57,4%, n=97 control; 53,65%, n=123 treatment 2mM y 49,63% n= 137 treatment 20mM) neither in the percentage of early (2,52%, n=119 control; 0,58%, n= 173 treatment 2mM y 0%, n=122 treatment 20mM) and late oocyte apoptosis (2,9%, n=103 control; 2,4%, n=85 treatment 2mM y 0,83%, n=120 treatment 20mM). We concluded that the addition of DMTU to collection medium (at the concentrations used) did not modify the rates of nuclear maturation and apoptosis in porcine oocytes.In future, the effects of DMTU supplementation in ROS production and oocyte cytoplasmic maturation will be evaluated.