Placental maturation and expulsion in Holstein and Nelore cows

Abstract

Morphological changes in the placenta at periparturition and the involvement of apoptosis controlling cell populations in the placentome were evaluated in Holstein and Nelore cows. Twenty-two Holstein cows at the end of gestation with normal non-induced parturition (group I) and 10 Holstein cows with induced parturition (group II) were used in this study. In addition, groups III and IV were constituted by 10 Nelore cows at the end of gestation with normal non-induced parturition and 21 Nelore cows with induced parturition, respectivelly. Binucleate trophoblastic cells, epithelial caruncular cells and apoptotic bodies were quantified by light microscopy. Apoptosis was further evaluated by transmission electron microscopy, ELISA and DNA electrophoresis in agarose gel. The number of caruncular epithelial cells did not vary between breeds with normal or induced parturition. The number of binucleate cells was significantly different between Holstein and Nelore cows with normal non-induced parturition (groups I vs. III), but their numbers were not significantly different between breeds when parturition was induced. In cows with normal non-induced parturition, the intensity of apoptosis, as assessed by morphometric analysis and ELISA, was significantly higher in group I when compared to group III. However, no difference in the intensity of apoptosis was found between groups II and IV. Characteristic apoptotic ladder pattern of DNA fragmentation was detected by agarose gel electrophoresis. Ultra-structural features of apoptosis in maternal and fetal epithelium as well as capillary vascular endothelium were identified by transmission electron microscopy. In conclusion, in Nelore placental maturation occurs precociously when compared to Holstein. In both breeds, apoptosis is an active physiological event that seems to be required for maturation and normal post-partum release of the placenta.Keywords: bovine, placentome, binucleate cell, epithelial cell, apoptosis RESUMO Foram avaliadas as diferenças morfológicas e a participação da apoptose na população de células do placentoma de vacas das raças Holandesa e Nelore no período periparto. Foram utilizadas 22 vacas da raça Holandesa com parto a termo (tratamento I) e 10 com parto induzido (tratamento II). Nos tratamentos III e IV foram utilizadas 10 vacas Nelore com parto a termo e 21 com parto induzido, respectivamente. As células binucleadas trofoblásticas e epiteliais carunculares e os corpos apoptóticos

Cellular Remodelling by Apoptosis During Porcine Placentation

“…() and Martins et al. () in murine, human and bovine placentation, respectively, and with our finding in goat placenta (unpublished data). In this way and given the type of placentation in swines, the apoptosis in term pregnancies would be responsible for the loss of contact between trophoblastic and maternal epithelial cells, allowing the elimination of foetal membranes during the farrowing, without loss of maternal tissues.…”

Apoptose e expressão de Bcl-2 e das caspases 3 e 8 em placenta bovina, em diferentes estádios de gestação

“…Estudos morfológicos demonstraram que a maturação placentária está relacionada à diminuição da população celular dos tecidos fetal e maternos no placentônio (Santos et al, 1997). A apoptose é um evento fisiológico ativo que parece ser requerido tanto para a maturação, quanto para a liberação normal da placenta após o parto (Martins et al, 2004).…”

DNA analysis of cattle parasitic protozoan Tritrichomonas foetus after photodynamic therapy

“…The last cleavage occurs when an activated nuclease cleaves the DNA at linker sites between nucleosomes, resulting in fragments that are multimers of 180-200 bp [41]. The presence of LMW fragments is a typical picture of apoptosis in various cell systems [42][43][44][45][46][47][48]. It is important to mention that the DNA damage caused by PDT is related to the treatment dose, length, etc., and that the resulting DNA fragmentation does not necessarily lead to cell death.…”