Структурные изменения в печени мышей при БЦЖ-гранулематозе и применении окисленного декстрана в возрастной динамике

Abstract

Introduction. Tubercular granulomatosis in newborns and children is much less common than in adults, and especially its visceral forms, including hepatic lesion. Oxidized dextran enhances the production of oxygen radicals, cytotoxic and bactericidal potential of phagocytes, accelerates the process of phagolysosomal fusion and elimination of the pathogen, reducing the granulomatous inflammatory process in organs. Aim. To study morphological changes in the liver of mice from the neonatal period to adulthood with the BCG vaccine administration and use of oxidized dextran. Materials and methods. Mice of the C57B1/6 line (200 animals in total) were divided into 4 groups: mice from the 1st (intact) group were injected with 0.02 ml/kg of 0.9% sodium chloride solution on the first day after birth. Mice from the 2nd group on the 2nd day after birth were injected with a solution of oxidized dextran with a molecular mass of 40 kDa. Mice from the 3rd group were injected with a solution of the BCG vaccine of 0.02 ml/kg on the first day after birth. Mice of the 4th group were injected with a solution of the BCG vaccine of 0.02 ml/kg, on the second day after birth – a solution of oxidized dextran with a molecular mass of 40 kDa. Results. The numerical density (Nai) of granulomas in the liver progressively increased from 28th to 56th day of the experiment in mice of the 3rd and 4th groups by 13.5 times. However, in mice of the 4th group, the number of granulomas was 1.4 times less than in mice of the 3rd group. The diameter of granulomas in the liver in mice of the 4th group was smaller on the 28th and 56th days in comparison with the same indicator in mice of the 3rd group by 2 times and 1.3 times, respectively. In mice of the 4th group, the volume density (Vv) of degenerated hepatocytes from 3rd to 5th day was 8 times lower compared to the same indicator in mice of the 3rd group, on the 10th and 28th days – 1.7 and 1.2 times, respectively. Vv of foci of hepatocyte necrosis in mice of the 4th group did not differ from that in mice of the 1st (intact) and 2nd (control) groups in all periods of observation, and was less on the 3rd and 56th days in comparison with the same indicator in mice of the 3rd (BCG) group by 3 times. On the 28th and 56th days of the experiment, mice from the 3rd and 4th groups showed an increase in the Nai of binuclear hepatocytes and hepatocytes with mitoses in comparison with the same indicator in mice of the 1st and 2nd groups. In mice of the 4th group, the number of binuclear hepatocytes, reflecting the reparative regeneration of hepatocytes, was 1.8 times greater than in mice of the 3rd group on the 28th and 56th days. Conclusion. Granulomas formation (the number and diameter of granulomas) in the liver of mice with the administration of the BCG vaccine and use of oxidized dextran was less marked in comparison with animals not treated with oxidized dextran, which indicates the effective elimination of the pathogen in phagocytes. Destructive changes (degeneration and necrosis of hepatocytes) in the liver parenchyma of mice with the injection of the BCG vaccine and subsequent use of oxidized dextran are significantly reduced, while the processes of reparative regeneration in the liver parenchyma of mice are activated, which is due to the hepatotropic action of oxidized dextran.