Adição de ácidos graxos poli-insaturados (PUFAs) de cadeia longa ômega-3 na maturação de oócitos suínos

Abstract

The production of embryos in vitro (IVP) is one of the main techniques applied to animal reproduction. Supplementation of in vitro maturation (IVM) media with long-chain polyunsaturated fatty acids (PUFA) of the omega-3 series may be relevant to the decrease of lipid droplets which hinder efficient IVP and cryopreservation of porcine embryos. This study evaluated the effects of supplementation of IVM media with two PUFA, the eicosapentaenoic (EPA) and the docosahexaenoic (DHA) on the nuclear maturation of pig oocytes. Follicles with 3-6 mm diameter were aspirated from ovaries collected at abattoirs from prepubertal gilts. The IVM medium was TCM-199 supplemented with 0.57 mM cysteine, 0.91 mM sodium pyruvate, 10 ng/mL EGF, 0.5 μg/mL LH, 0.5 μg/mL FSH and 0.1% PVA. The IVM rates were evaluated for groups having nearly 30 cumulus-oocyte complexes in four treatments, including media supplemented with: 10% porcine folicular fluido (PFF), as a control; 50; 100 and 150μM of each PUFA. FOS supplementation and cAMP was also performed to evaluate the possible toxicity of these fatty acids. After 44 h of IVM, oocytes were stained with Hoechst 33342. Differences were observed between IVM rates obtained in media supplemented with different levels of EPA from 100 uM, compared to the control (P> 0.05). The IVM rates observed in media supplemented with DHA at concentrations from 100 uM were lower than those in the control (P <0.05). When compared with supplemented FFS and cAMP means IVM rates swarming with 50 mM of EPA and DHA did not differ (P> 0.05). These results indicate that supplementation of IVM medium with EPA and DHA influenced negatively the rate of nuclear maturation, suggesting a toxic effect for swine oocytes.