Histological characterization of the placenta of zebu cattle raised in Oriental Amazonia, Brazil

Abstract

The aim of the present work was to analyze the histological characteristics of placenta of zebu, Bos taurus indicus, raised in the Oriental Amazon. Pregnant uteri from 4 to 8 months of gestation were collected. Samples were seccionated from the cérvix to the body of the uterus. Samples were inverted for fetal age verification and to collect the placentomes. Placentomes were collected from pregnant and non-pregnant oval, circular and fusion uterine horns. Then, they were fastened in formalin solution 10% for subsequent histological preparation in paraffin and hematoxilin-eosin for coloration. Histologically, the endometrium was well developed with vascular covering of the caruncle and presenting gaps. The cotyledone had villous covered by trophoblast uninucleated and binucleated giant cells. The mucosal epithelium was simple prismatic and corium glands in the limit of the myometrium presented tortuous appearance. Caruncule and cotyledone were covered respectively by simple cubic epithelium and trophoblast giant binucleate cells. A compact fibrovascular estrome was formed from the 6th month of pregnancy. It was concluded that, even having anatomical differences among found structures, the placenta presents similar histology in all periods studied, and placentomes growth during gestation seems to be related to the multiplication of cells that make up the cotyledons and caruncule, as well as vascularisation. Keywords: Placenta, uterus, zebu cow, trophoblast giant cells.