In vitro maturation in a defined medium without oxidative substrates

BREININGER ELIZABETH; CETICA PABLO; GAGNETEN PAULA; GUTNISKY CYNTHIA

Virtual

Congreso; IV Reunión Conjunta de Sociedades de Biología de la República Argentina, Encuentro virtual, 9 ? 15 septiembre 2020.; 2020

Sociedades de Biología de la República Argentina

Most metabolic studies carried out in cumulus oocytes-complexes (COCs) refer to carbohydrates as they are the main substrates in the culture media. There is limited information about the use of endogen lipids (EL) as oxidative substrates. The aim of this work was to study the endogen lipid consumption of bovine COCs during maturation in absence of other oxidative substrates. Maturation was performed in defined media, SOFm, (without pyruvate and lactate) supplemented with FSH, LH, EGF, gentamicin, insulin and PVA. Oocytes were randomly divided in 5 groups: a) SOF + glucose 5,5mM, b) SOF + L-Carnitin (β-oxidation fatty acid stimulator), c) SOF + glucose + L-Carnitin, d) SOF + Etomoxir (β-oxidation fatty acid inhibitor) and e) SOF (without any supplementation). The proportion of nuclear maturation was evaluated by the presence of metaphase II after Hoechst 33342 staining. The COCs endogen lipid content was determined by Nile Red staining and its fluorescence was quantified using digital photomicrographs taken with an epinofluorecence microscope. Significant increase in nuclear maturation rates were observed in presence of glucose, L-carnitin and the combination of both, respect to the group without any supplementation and the group supplemented with etomoxir. No difference was observed between these two last groups. For the endogen lipids content, it was observed that in media without supplementation, at the end of the maturation process, lipid content was lower than in the group supplemented with glucose (p