Morphological and Immunohistochemical Characteristics of Experimental Mandibular Fractures Healing Process

Abstract

The aim of the study is histological assessment of the effect of oxytocin local application on mandibular fractures healing.

Material and methods. The investigated material was the lower jaw in the fracture zone, fastened by the bone suture method, of 24 Wistar male rats 220–250 g by mass. The preparations were subjected to the same histological processing and studied in light microscope. Reactions with monoclonal antibodies were performed to identify the expression of Ki67, p56, bcl 2, caspasa 3 proteins.

Results. It was established that the dynamics of the bone-wound process in mandibular fractures and the operative fastening of fragments by bone suture is characterized by phase. Light-optical and immunocytochemical studies showed the restoration of the integrity of the damaged mandible after the fragments were fixed with bone suture through the proliferation of the cambial layer cells of the periosteum and low-differentiated mesenchymal stromal bone marrow cells. The data obtained indicate that the use of oxytocyte had an optimizing effect on reparative osteogenesis. When this occurs, the correction of elementary reparative processes of histogenesis at the level of expression of pro- and anti-apoptotic genes of bone tissue cells (decrease in the apoptotic dominant of osteoblasts in terms of p53 expression, inhibition of the enzyme cascade, implementation of programmed cells death in terms of caspasa 3) takes place. At the same time, the activity of the anti-apoptotic bcl-2 gene and the Ki- 67 gene increased in osteoblasts and endothelial cells, which determines the proliferative component of reparative osteogenesis, increased in the regenerate.