Altas concentrações de pentoxifilina na capacitação espermática : toxicidade, motilidade espermática e produção in vitro de embriões bovinos

• Ano de defesa: 2016
• Autor(a) principal: Wingert, Fabiana Mariani
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Faculdade de Agronomia e Zootecnia (FAAZ); UFMT CUC - Cuiabá; Programa de Pós-Graduação em Ciência Animal
• Palavras-chave em Português: Fertilização; Metilxantina; Sêmen; Reação acrossômica; CNPQ::CIENCIAS AGRARIAS; Fertilization; Methylxanthine; Semen; Acrosome reaction
• Link de acesso: http://ri.ufmt.br/handle/1/5559

The in vitro embryo production (IVP) is a reproductive biotech used to spread the genetic characteristics of the female, being a tool that helps in the understanding of infertility cases, directly increasing the genetic potential of animals and herd productivity. The selection of bulls for fertilization of oocytes on the PIV is of great importance in guaranteeing acceptable yields of this technique, however, in most cases, semen used in PIV is cryopreserved and during the cryopreservation process can damage the sperm membrane , excessive production of oxidative stress (ROS), premature maturation and increase the proportion of capacitated spermatozoa acrosome- reacted and being associated with reduced motility, viability, membrane integrity and low post-thaw fertility. Some studies have been conducted to minimize these losses quality after cryopreservation and preserve fertilizing capacity of sperm cells to promote increased motility and assisting in oocyte fertilization. Pentoxifylline is an inhibitor of fosfodiesterese drug that has been used in assisted reproduction techniques for promoting increased motility and consequent higher fertilization rates. However, its use in breeding cattle has not been adequately studied. The objective of this study was to determine whether different concentrations of pentoxifylline (10 and 20mM) improve the characteristics of semen and therefore IVF bovine embryos. It used the semen four bulls tested for in vitro production, passed in discontinuous Percoll gradients (45 to 90%) and divided into treatment: Control with addition of 10 mM and 20 mM, and subsequently used for in vitro production and analysis motility, vigor mitochondrial activity, sperm capacitation and oxidative stress (ROS) of fertilization and cultivation methods. The experiment was conducted in randomized blocks and the media analyzed with 5% significance level. The motililidade force and sperm decreased with the addition of pentoxifylline (P <0.0001, P = 0.0002) as well as cleavage (P = 0.0173), blastocyst production (P = 0.0424) increase beyond spermatozoa with degenerative acrosome reaction (P = 0.0004), but no difference was observed in the production of reactive oxygen species or the mitochondrial cytochemistry activity (P> 0.005). It follows that the use of pentoxifylline in concentrations of 10 and 20 mm have been detrimental to spermatozoa as well as the in vitro production of bovine embryos, however protocols for use of pentoxifylline in bovine semen are scarce need for further studies of technical standardization.