Maliuk M. Properties of stem cells and scientific-experimental study of their use in veterinary medicine

In the thesis is solved the topical issue of veterinary medicine – the investigation of the properties of mesenchymal stem cells (MSC) of animals. Presented immunohistochemical and cytogenetic studies reveals the current understanding about the biology of MSC depending on the species of an animal, methods of obtaining, conditions of cultivation and passaging and their impact on the optimization of reparative processes in experimental damaged tendon of animals. Was established that optimal conditions for obtaining the fraction of mononuclear cells from the bone marrow of horses which are enriched by population of MSC are centrifugation of bone marrow cell suspension in ficoll density gradient ?=1,076 with centrifugal force of 300 g. MSC of the bone marrow of rats, rabbits, dogs and horses and the umbilical cord of foals are heterogeneous, that confirmed by immunohistochemical studies. They express markers of mesenchymal (vimentin, actin), muscle, epithelial and nerve (E-cadherin, N-cadherin) cells. Confirmed the multipotent properties of MSC of the bone marrow of dogs by their ability to differentiate in osteogenic and adipogenic directions. It was proved the suppressive effect of MSC on the different subpopulation of lymphocytes after their administration into bloodstream of rabbits, that confirmed by the significant reduction in the total populations of T-, B- and 0-lymphocytes in the blood of these animals. It was established that using of chelating dissociation of MSC monolayer of rabbits by using the the ethylenediaminetetraacetic acid at early passages of cultivation has advantages over using the enzymatic method of dissociation with a solution of trypsin, because of less impact on their cytogenetic variability that allows to get the cell culture with less quantitative and qualitative changes in chromosome apparatus of cells (aneuploidy, polyploidy). It was established that in a rabbit bone marrow exist a resistant stem cells population that is able to active cloning after 48 hours of storage of primary material at 4 о C. It was proved that intratendon administration of allogeneic MSC activates on the 7th and 21st day the recovery of damaged tissues, that were manifested by the restoration of the structural and functional organization of a Achilles tendon.