[Activation of regeneration of red and white pulp of the spleen after the combined transplantation of HSC and MSCS in terms of exposure to ionizing radiation].

The purpose of this work was to study the effect of combined transplantation of multipotent mesenchymal stromal (MSCS) and hematopoietic stem cells (HSCs) isolated from the placenta, on the regeneration of white and red pulp of the spleen under physiological conditions and in conditions of exposure to ionizing radiation. Methods. The experiments were performed with laboratory mice-males. We studied the influence of ionizing radiation dose of 4.0 Gy. Animals of the experimental group were intravenously infused into MMSC and GSK respectively at a dose of 6 million cells/kg and 330 thousand cells/kg, suspended in 0.2 ml of 0.9% NaCl solution. The selection of hematopoietic stem cells was carried out using the direct technique of immune magnetic separation. Were studied the following morphometric parameters of the spleen: the average area of lymphoid follicles, the average area of zone of lymphoid follicles, average size of germinal center of lymphoid follicles, average size T-zones of lymphoid follicles, the average distance between the centers of the follicles, the average cellularity of the red pulp. Results. As a result, of research obtained that after exposure to ionizing radiation on the background of combined transplantation of HSC and MSCS there is an increase in size of lymphoid follicle at the expense of area B-zone of the follicle, the area germinative center of the follicle, restoring the content of lymphoblasts and lymphoblasts and lymphocytes to normal values. On the background of transplantation MMSC and GSK in terms of radiation exposure changes and the red pulp of the spleen. The increase in the density of cells in the red pulp of the spleen and, as a consequence, of the increase of the distance between the centers of lymphoid follicles. The increase in the density of cells in the red pulp occurs due to the increase in the content of erythroid cells and by increasing granulocytes. Key words: ionizing radiation, multipotent mesenchymal stromal cells, hematopoietic stem cells, spleen, regeneration. Conclusion. Studies have shown the effectiveness of combined transplantation MSC and GSK in respect of the main morphometric parameters of the spleen after exposure to ionizing radiation.