Aspectos morfovasculares e expressão de VEGF na placenta da égua

Abstract

The aim of this study was to evaluate the vascular changes in the placenta of mares, with emphasis on histological aspects, vascular proliferation and expression of endothelial growth factor, or VEGF. Vascular modifications were compared in the placenta of healthy mares and mares with chronic laminitis. Three articles are presented: The first one sought to establish, in the form of a literature review, the aspects related to the occurrence of oxidative stress in the gestation of mare and its relation with the vascular modifications in the placenta. In a second moment the expression of VEGF in the placenta of mares was demonstrated. A third study evaluated the histopathological changes in the placenta of mares with chronic laminitis, based on vascular morphometry, proliferation of fibrous tissue in the vessel wall and vascular density. The main conclusions were that the mare may present with late placental insufficiency findings, similar to those found in women with preeclampsia, and that these alterations may be associated with oxidative stress during pregnancy. VEGF expression in the equine placenta occurs in the trophoblastic cells of the microvilli and areolar region, in addition to vascular wall and endothelium. It has also been demonstrated that mares with chronic laminitis show greater vascular proliferation in the body and pregnant horn of the placenta, as well as reduction of vascular lumen, with increased vascular wall thickness characterized by deposition of fibrous connective tissue in the non-pregnant horn.