Scientific publications

The analysis of 15 placenta samples (1x1 cm) obtained from three calves of domestic reindeer, aged 4 years, was carried out directly at birth. Tissue samples were placed in a 10% neutral formalin solution for fixation. Next, they were dehydrated by successively immersing them in alcohol solutions of increasing concentration. After preparing the samples, they were treated with chloroform on a Cytadel 2000 histological processor (Shendon) for clarification, and then poured into Histomix paraffin (Biovitrum) to prepare for further analysis. The paraffin blocks were cut into thin slices using a microtome MICROM HM340E. Microscopic examination and documentation of the obtained sections was carried out on an AxioScope.A1 (ZEISS) microscope equipped with an AxioCam MRc5 digital camera.Analysis of micro-preparations did not reveal direct contact between chorioallantois villi and uterine epithelial cells. The study established a rich and fairly good blood supply to the placenta, including the amniotic membrane and chorioallantois villi (both stem and terminal). Collagen fibers formed the basis of both the thickened stroma of the amniotic membrane and various types of chorioallantois villi. Outgrowths of the amniotic membrane, covered with a multilayer epithelium, were observed in all the studied placenta samples. This epithelium was represented by tall prismatic cells characterized by the presence of many long microvilli on the apical surface forming a pronounced brush border. The cytoplasm of these cells contained a significant number of vacuoles and brown inclusions, which turned out to be CHIC-positive. The main component of the intercellular substance was acidic mucopolysaccharides. A significant number of macrophages were found in the connective tissue of chorioallantois villi. The observed features of the histoarchitectonics of the placenta of the northern domestic reindeer reflect the adaptive mechanisms of ruminant mammals associated with successful gestation and birth of offspring in the extreme climatic conditions of the Arctic territory of the Republic (Sakha) Yakutia, characteristic of this species.