Avaliação de componentes estruturais do placentomo da vaca Nelore

• Ano de defesa: 2009
• Autor(a) principal: Evandro dos Reis Machado
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Nelore; células binucleadas; placentomo; vaca; Veterinária; Placenta Morfologia; Vaca Reprodução; Placenta Exames
• Link de acesso: http://hdl.handle.net/1843/LGPD-7QUMTG

This study was conducted to better understand the morphologic characteristics of the placentome of the Nelore cow throughout gestation. The experiment was conducted in labs of the Veterinary School of the Federal University of Minas Gerais and in the Cytology, Histology and Embryology lab of the Federal University of Uberlandia, using uteri of 52 Nelore cows collected in a slaughterhouse located in Araguari - MG. For the estimation of gestational age were used aspects of fetal development. It was collected a fragment of a placentome of the uterine horn ipsilateral to the corpus luteum. The ovary containing the corpus luteum was also collected. All samples were immersed in a solution of formol 10% before reduced to small size and conservation until inclusion in paraffin using routine histological technique. The study of volumetric proportion was done using a light microscope equipped with an integrated ocular (10x Zeiss KPL). It was also made the quantification of epithelial cells in crypts of caruncles by light microscopy and the help of an ocular micrometric with a grid of 100 divisions. For the macroscopic evaluation the experiment was designed in seven periods during the pregnancy, while for the microscopic one the periods of pregnancy were divided into initial, middle and final thirds of pregnancy. The corpus luteum in the right ovary was found in 61.54% of cases. The average number of placentomes found in the pregnant uterine horn was 43.08±9.37. Placentomes located in the distal portion of the pregnant uterine horns developed by 120-150 days, with apparent stabilization, while those in the proximal region were smaller than the ones of the distal and medial regions. Placentomes of the medial region showed more evident growth by 90 to 120 days, with apparent stabilization around 180-210 days. It was found a decrease in the number of maternal cells of the epithelium in the crypts in advanced pregnancies. The average number of binucleate trophoblast cells remained similar throughout gestation, as well as the volumetric proportion of components of the maternal and fetal tissue and maternal blood vessels, whereas the fetal blood vessels showed a progressive increased