THE EFFECT OF L-CARNITINE ON THE LEVEL OF LATE APOPTOSIS OF MATURE PORCINE VITRIFIED-WARMED OOCYTES

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

Ciudad Autónoma de Buenos Aires

Jornada; IX Jornadas de Jóvenes Investigadores; 2019

Facultad de Ciencias Veterinarias UBA

L-carnitine (LC) plays an important role in the catabolism of lipids and protects cells from the damage caused by reactive oxygen species (ROS) due to its antioxidant activity. Previous studies in our laboratory demonstrated that the addition of 0.6 mg/mL of LC in the in vitro maturation (IVM) medium decreases the level of intracellular ROS and the amount of intracellular lipids of the oocyte compared to the control (without LC) without affecting the nuclear maturation rates and the parameters of in vitro fertilization. Vitrification is a cryopreservation technique that consists of rapid cooling of the cells in a liquid medium, in the absence of ice crystal formation. Considering that the oxidative stress and the high concentration of lipids in porcine oocytes is detrimental to cryopreservation, the use of 0.6 mg/mL of LC during IVM could improve the efficiency of this biotechnology. We demonstrated that the level of early apoptosis and viability of porcine oocyte matured with 0,6 mg/mL of LC in the IVM medium and then vitrified-warmed did not differ with the control. The aim of this study was to evaluate the effect of the addition of 0,6 mg/mL of LC during IVM on late apoptosis of mature porcine vitrified-warmed oocytes. The cumulus-oocyte complexes (COC) were obtained by follicular aspiration from slaughterhouse ovaries and matured in vitro without LC (control) or with 0.6 mg/mL of LC in the maturation medium (TCM-199 supplemented) for 44 h at 39°C and 5% CO2. Then, the oocytes were denuded and vitrified using support similar to a Criotop. One week later, they were warmed, and the level of late apoptosis (TUNEL assay) was assessed. Data were analyzed by Statistix software (Fisher´s test). A p≤ 0.05 was considered significant. No significant differences were detected in the level of late apoptosis (4.76 % vs. 2.7 %) between the control (n = 84) and LC treatment (n = 74). In conclusion, the addition of LC during IVM did not modify the level of late apoptosis on mature vitrified-warmed porcine oocytes.