Resposta do córtex ovariano bovino submetido ao cultivo in vitro e xenotransplante após vitrificação associada ao resveratrol

Abstract

In order to increase the reproductive efficiency of animals of high genetic value, biotechniques were developed for the preservation of ovarian tissue, such as in vitro culture, vitrification and xenotransplantation. However, difficulty for neovascularization in xenotransplantation and formation of intracellular ice crystals in vitrification are examples of difficulties faced by these biotechnologies. In this sense, this work intended to evaluate whether vitrification of ovarian cortex associated with resveratrol allows better preservation of the viability and developmental capacity of preantral follicles after xenotransplantation, and if xenotransplanted ovarian tissue after vitrification with resveratrol has a greater angiogenic capacity and lower oxidative stress. For this purpose, cow ovaries were collected from a fridge located in Uberlândia-MG, fragmented and distributed in fresh control, vitrified control with resveratrol, vitrified culture with resveratrol, vitrified xenotransplantation with resveratrol, vitrified control without resveratrol, vitrified culture without resveratrol, vitrified xenotransplantation without resveratrol, fresh culture, and fresh xenotransplantation. The bovine ovarian tissue xenotransplantation was made in mice. The viability of the ovarian tissue was evaluated by confocal microscopy, which allows to verify the occurrence of cellular apoptosis and oxidation of the tissue submitted to various treatments. The aim of this study was to evaluate viability, apoptosis and oxidation of bovine ovarian tissue after in vitro culture, vitrification associated with resveratrol, and xenotransplantation. All data were analyzed using the statistical analysis program R version 3.0.2. All treatments presented a reduction in the levels of reactive oxygen species (ROS) and in the levels of cellular apoptosis comparing to the fresh control. In the treatments with in vitro culture, the vitrified group with resveratrol showed a reduction in ROS levels between days D1 and D7 of the culture. The group of vitrified fragments with resveratrol presented a lower level of cellular degeneration compared to the vitrified fragments without resveratrol in D1. The xenotransplanted vitrified group demonstrated the lowest rate of cellular apoptosis. It is concluded that resveratrol presents protective effects of tissue viability during vitrification processes.