Efeito da adição da cantaxantina na produção de embriões bovinos in vitro

Abstract

In this work three different concentrations of a natural nonenzymatic antioxidant (Canthaxanthin) were added to in vitro maturation medium, the work consisted of two experiments, in the first experiment groups of oocyte-cumulus complex were matured, without Canthaxanthin, (Control Group C, 155 oocytes), with 1 μM (T1 Group, 153 oocytes), with 0.5 μM (T2 Group, 153 oocytes), and with 0.25 μM (T1 Group, 153 oocytes), 24h after in vitro maturation, the oocytes of each group were denuded, fixed, then stained with Lacmoid 1% to visualize the oocytes´ nuclei, the oocytes that showed the metaphase II spindle and/or the first polar body were classified as maturated oocytes, the nuclear maturation rate did not show significant difference between the experimental groups (P>0.05), the percentage of the oocytes that reached the MII was C, T1, T2, and T3, 74.8%, 74.17%, 78%, and 77.9%, respectively, the concentration of 0.5 μM (T2) showed the highest nuclear maturation rate among the experimental groups, so it was utilized in the second experiment. In the second experiment two groups were utilized (C, and T2 118, and 113, respectively), to verify the effect of Canthaxanthin on the in vitro embryonic development, neither the cleavage rates (C:72.9%, and T2: 76%), nor the total blastocyst rates (C:44.9%, and T2: 39.8%) showed significant difference (P>0.05), after the classification of embryonic development stages (168 hpi), the early blastocyst rate (C:2.54 %, and T2: 8.84%), and the blastocyst rate (C:11 %, and T2: 3.53%) showed a significant differences (P<0.05), but the other stages did not show significant differences (P<0.05), (C, and T2, expanded blastocyst, and hatched blastocyst, 17.8%, 13.6%, and 19.5%, 8% respectively); the results of our work showed that the Canthaxanthin did not affect the nuclear maturation of the in vitro matured oocytes, or the in vitro embryo production.