Utilização de Plasma Rico em Plaquetas no Meio de Fertilização in vitro de Oócitos Bovinos.

Abstract

Culture media represent the physicochemical and utritional support necessary for maintaining the survival and promoting the development of gametes and embryos in vitro. Aiming to replicate a microenvironment closer to in vivo conditions, new formulations and the addition of various substances have been tested. Platelet-rich plasma (PRP) contains serotonin, adhesion molecules, growth factors (FGF, TGFβ, PDGF, IGF, and EGF), as well as cytokines that may positively modulate the fertilization microenvironment and favor embryonic development. Due to its bioactive properties, this study investigated the effect of adding PRP to the fertilization medium on in vitro bovine embryo production. Bovine cumulus–oocyte complexes (COCs) obtained from a local slaughterhouse were fertilized in the presence of 2.5%, 5%, and 10% PRP. The gene expression of OCT4, IFNT, HSP70, SOD2, and GLUT1 was evaluated only in the Control, 2.5%, and 5% groups by RT-PCR, with three replicates consisting of pools of five embryos each, using the 2ΔΔCT method. Cleavage (D2) and blastocyst (D7) rates and gene expression data were analyzed by ANOVA (p<0.05). Regarding cleavage and blastocyst formation rates, differences were observed between the Control (91.9 ± 3.9; 44.6 ± 9.0), 2.5% (87.9 ± 6.4; 39.0 ± 14.1), and 5% (85.8 ± 7.4; 35.1 ± 11.4) groups compared with the 10% group (61.1 ± 9.9; 17.6 ± 4.9). The OCT4 and IFNT genes were more highly expressed in the 5% group, whereas HSP70 showed greater expression in the 2.5% and 5% groups. The SOD2 gene was less expressed in the 2.5% group, while GLUT1 showed lower expression in the 5% group. Therefore, the effect of PRP was dose-dependent, with the 10% concentration exhibiting a detrimental effect on cleavage and blastocyst formation rates. In contrast, 5% PRP during the fertilization process improved the quality of bovine embryos, as evidenced by the higher expression of genes associated with preimplantation embryonic competence.