Microscopic changes in experimentally damaged rabbit muscles under the influence of transplanted mesenchymal stem cells

Abstract

The relevance of the work is related to the possibility of artificially adjusting the intensity of skeletal muscle tissue regeneration in animals, which will significantly affect the tactics of rehabilitation treatment of muscle injuries in the future. The purpose of the research was to determine the effectiveness of the transplanted mesenchymal stem cells on the recovery processes in experimentally injured rabbit muscles. The method of histological examination of microscopic changes in the experimentally damaged muscle tissue of the pelvic head of the biceps femoris muscle of rabbits was used. Microscopic studies of the regeneration process of experimentally damaged striated muscle tissue established that in animals after intramuscular injection of allogeneic mesenchymal stem cells, connective tissue developed around the defect on day 2 of the experiment. On day 4, a large number of stem cells were detected in the connective tissue at the site of muscle tissue damage. On day 6, only relatively small foci of muscle tissue regeneration were observed in this area. On day 8, only small focal accumulations of stem cells were detected in this location. On the 10th day after intramuscular injection of mesenchymal stem cells, newly developed muscle fibres appeared at the site of injury. On the 14th day after intramuscular injection of mesenchymal stem cells, fully developed muscle fibres and intermuscular connective tissue were observed at the site of injury. In rabbits, after intramuscular injection of allogeneic mesenchymal stem cells, all regenerative processes were more active than in animals of other experimental groups and were completely completed by day 14 of the experiment. The practical value of the results obtained is to clarify the patterns of development of reparative processes in the damaged muscle area and to determine the effectiveness of using transplanted allogeneic mesenchymal stem cells in stimulating recovery processes, which is important to consider in the treatment of muscle injuries using regenerative therapy