Comparative morphological features of the placental barrier and localization of estrogen receptors alpha in the placenta of cows and buffaloes.

摘要

The present study was conducted to identify the morphological characteristics of the placental barrier and localization of oestrogen receptor alpha in cow and buffalo placentas. Placentomes were collected from 3 pregnant cows and 3 pregnant buffaloes at the 5th and 6th months of gestation, respectively. The placentomes were fixed by using 10% neutral buffered formalin for immunohistochemistry and were post fixed in 3% glutaraldehyde for light microscopy. Indirect immunoperoxidase staining methods using monoclonal antibodies against bovine ER alpha as the primary antibody was applied. The morphometric data were obtained by using Q500 MC Image processing and analysis programme. Histological examination revealed that there is a great similarity in the structure of the placental barrier of cows and buffaloes, whereas the typical six slayers of tissue were seen separating the fetal blood from the maternal one. These layers were the maternal endothelium, thin layer of maternal connective tissue, maternal uterine epithelial cells, fetal trophoblast cells, fetal connective tissue and fetal endothelium. Nuclear immunoreactivities occurred mainly in the maternal crypt epithelium and maternal connective tissue cells. In about 1000 maternal uterine cryptal cells, 87.6% were positive cells for ER alpha in the cow placenta and about 67.8% were positive cells in the buffalo placenta. In conclusion, although there is a great similarity in the structure of the placental barrier and expression of ER alpha in the placentas of cows and buffaloes, interbreeding between the two species is impossible due to the different number of chromosomes. The placenta of cows seems to be less responsive to oestrogen in comparison to that of buffaloes..