Avaliação da suplementação do meio de maturação in vitro de ovócitos bovinos com beta-NGF

Abstract

The in vitro embryo production (IVP) is already a widely used and proven viable technique, however, it can be improved. A positive relationship was verified between the amount of Beta-NGF in sperm and cleavage and blastocyst rates in in vitro embryo production, so this is the first work that evaluates Beta-NGF supplementation in IVP media, aiming to identify Beta-NGF receptors (p75 and Trk), verify the effect on embryo production, identify the best concentration and evaluate the quality of the supplemented structures. Cumulus oocyte complexes (COC) were stained by indirect immunofluorescence for p75 and TrK receptors and evaluated by confocal microscopy and routine PIVEs were performed. Both receptors were localized to oocytes and cumulus cells. Supplemented PIVEs had better rates of cleavage and blastocyst formation (paired t-test, p < 0.05). To evaluate the cytoplasmic structure of in vitro matured oocytes, it was divided into two groups, with and without beta-NGF supplementation. Student's t test (p≤0.05) was chosen to verify whether there was a difference between the two treatments. The results showed that supplementation induced an increase in the amount of mitochondria (p≤0.0424), in addition to reducing the production of ROS (p≤0.0001), and consequently apoptosis and cell death (p≤0.0027. For the evaluation of the best concentration, the experiment was divided into three groups: control, supplementation with 100ng/ml and 500ng/ml, applying paired t test, p < 0.05. with protein supplementation in the improvement medium. cleavage was better in the 100 ng/ml group, blastocyst production showed no difference. Thus, we can say that supplementation with Beta-NGF can be a good alternative to improve IVP performance.