DYNAMICS OF BIOCHEMICAL MARKERS OF HUMORAL IMMUNITY AND METABOLISM IN MANDIBULAR BONE TISSUE UNDER INFLUENCE ON REPARATIVE OSTEOGENESIS

Abstract

The scientific and practical significance of our study lies in the application of various therapeutic measures aimed at accelerating the processes of reparative osteogenesis in the presence of perforated defects in the bone tissue of the mandible using hydroxyapatite-containing osteotropic material “Biomin GT bone graft» and thymaline (injections into the surrounding soft tissues) analyzed in our article.
 The aim of the study is to investigate the dynamics of secretory immunoglobulin A content and activity of acid and alkaline phosphatases in the oral fluid of rats under the conditions of influence on the processes of reparative osteogenesis when filling the bone defect with osteotropic material and injecting thymaline into the surrounding soft tissues at different study periods.
 Materials and methods. Experimental studies were conducted on 30 mature WAG population rats weighing 160-180 g, which were divided into five groups. The control group consisted of 6 intact rats, the first group included rats with a simulated hole defect of the mandible, the second group included rats with a simulated hole defect followed by closure of the bone defect with hydroxyapatite-containing osteotropic material, the third group included rats with a mandibular defect after thymaline injections into the surrounding soft tissues, and the fourth group included animals with a defect after filling the bone defect with osteotropic material and injections of thymaline into the surrounding soft tissues. The concentration of sIgA in the oral fluid of rats was determined by enzyme-linked immunosorbent assay using «The IgA Saliva ELISA kit» (Diametra, Italy). The activity of alkaline (ALP) and acid phosphatase (AP) in the biomaterial was measured using a set of reagents “Granum» Ukraine, Kharkiv. The optical density was measured using a STAT-FAX 303+ immunoenzyme analyzer.
 Results and discussion. A decrease in the content of sIgA in the oral fluid of rats of groups I-IV was found both on day 3 and day 7 of the study compared with the control group. On the 14th day, an increase (by 16.7%) in the content of sIgA in the oral fluid of rats of group IV was determined compared to the first group. The content of sIgA in the oral fluid of rats of groups I and III remained below the control by 29.6%, 32.7%, 29.9%, respectively. On the 28th day, only in rats of group IV, sIgA exceeded the value of its content in rats of the control group and was 52.6% higher compared to rats of group I. On the 3rd day, an increase in the activity of ALP from 102% to 111%, respectively, was observed in the oral fluid of rats of groups I-IV compared to intact animals. On the 7th day, the greatest (18.9%) decrease in the activity of ALP was observed in the oral fluid of rats of group IV; on the 14th day, only rats of group IV showed a decrease in the activity of ALP (by 38.1%) compared to the 3rd day. On the 28th day, a decrease in the activity of ALP (by 43.12%) was observed in the oral fluid of rats of group IV compared to day 3 and was equal to the control. On the third day, there was an increase in the activity of AP in the oral fluid of all rats. When comparing the values of AP activity in the oral fluid of rats of groups I and IV, a difference of 17.3% was determined. In rats of group IV on day 14: 25.6% decrease in AP activity compared to day 3 of the study, although it differed from the control group. However, statistically significant decrease in AP activity was observed in rats of group IV compared to groups I-III.
 Conclusions. In rats with a simulated mandibular perforation defect on the third and seventh days of observation, a deficiency of sIgA in the oral fluid was observed, indicating a decrease in the functioning of the humoral link of local immunity. In rats of group IV, on the 14th and 28th day of the study, the sIgA content was normalized. There is an activation of reparative osteogenesis in the bone tissue of the mandible in rats with a simulated hole defect under the conditions of its subsequent closure with hydroxyapatite-containing osteotropic material and injections of thymaline into the surrounding soft tissues. The determination of biochemical markers of bone metabolism, in particular alkaline and acid phosphatase in the oral fluid in mandibular fractures, can be used in clinical practice to improve the efficiency of diagnosing reparative osteogenesis in the jaw bones.