Influência de diferentes tratamentos com progesterona exógena em doadores de ovócitos na produção in vitro de embriões bovinos

Abstract

The embryo production in vitro (PIV) represents a way to increase the gamete profit from animals with high zootechnic level. In spite of the advances obtained in the PIV in the last few years, the production of transferable embryos still is low. The aim of this review is to discuss ways to product embryos in vitro, as well as ways of formation and maturation of oocytes that can be related with the effectiveness of the results obtained. Some studies show that the influence of the follicular growth factors, of the gonadotrophines, of the steroides and the hormones on the follicular development and the quality of the complex oocytes-cumulus (COCs). The follicular phase of slow growth is critic for the development capacity of the oocytes reaching the final competence and length. The information about the endocrine influences still aren’t sufficient or the dependence of growth of small antral follicles when occur a loss in the ovacitary or follicle function. A variable number of different technics and protocols for the treatment of oocytes donors are being described with the aim of improving the results, the recovering rate of COCs and the competence development the oocytes collected in vitro. From these considerations presented in this review it’s possible to verify the importance of a bigger understanding of the factors that are involved in the PIV process, with the aim of allowing new alternatives that increase the results obtained in programs of assisted reproduction