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I. Ye. Kolpakov1, V. Ì. Zyhalo1, V. H. Kondrashova1, H. M. Chobotko2, L. O. Leonovych1
1State Institution «National Research Center for Radiation Medicine, Hematology and Oncology of the
National Academy of Medical Sciences of Ukraine», 53 Yuriia Illienka St., Kyiv, 04050, Ukraine
2Institute of Agroecology and Environmental Management of the National Academy of Agrarian Sciences
of Ukraine, 12 Metrolohichna St., Kyiv, 03143, Ukraine
GENETIC POLYMORPHISM OF MANGANESE SUPEROXIDE DISMUTASE AND CHANGES IN OXIDATIVE STRESS MARKERS IN CHILDREN – RESIDENTS OF RADIOACTIVELY CONTAMINATED TERRITORIES AND CHILDREN EXPOSED TO STRESSFUL LIFE EVENTS DURING WARTIME PERIOD
Objective: to determine the distribution of genotypes of genetic polymorphism of manganese superoxide dismutase
and to assess the changes in oxidative stress markers in children-residents of radioactively contaminated territories
and children exposed to stressful life events during the wartime period.
Materials and methods. The examined school-age children are residents of radioactively contaminated territories
(RCT) and children exposed to stressful life events during the wartime period. All of the examined children had no
clinical signs of respiratory pathology. The SOD2 gene Val16Ala polymorphic marker was studied in the molecular
genetic laboratory of the State Institution «Reference Center for Molecular Diagnostics of the Ministry of Health of
Ukraine». Genotypes of the SOD2 gene Val16Ala variant were determined by the polymorphic chain reaction (PCR)
method and subsequent restriction fragment length polymorphism (RFLP) analysis. To determine the signs of oxidative stress and the balance in the lipid peroxidation (LPO) system – antioxidant protection (AOP), studies were performed on the content of the LPO end products in the blood serum that react with thiobarbituric acid (TBA-active
LPO products – malondialdehyde – MDA), as well as studies on the activity of enzymes – antioxidants – superoxide
dismutase, catalase, glutathione peroxidase in erythrocytes.
Results. In the study of genotypes and alleles of SOD2 gene Val16Ala polymorphism in children-residents of RCT and
children exposed to stressful life events during the wartime period a tendency towards a decrease in the frequency
of the VV genotype and an increase in the prevalence of the AV genotype and AA genotype, decrease in the V allele
prevalence and an increase in the prevalence of the A allele distribution was noted compared with the reference values of the those of the control group. When assessing the average values of oxidative stress markers in both main
groups in relation to the control, superoxide dismutase activity was reduced, the content of LPO end products in the
blood serum, the activity of catalase and glutathione peroxidase tended to increase. A study of the average values
of oxidative stress markers in genotypes for the SOD2 gene Val16Ala polymorphism showed that both in children living in the RCT and in children exposed to stressful life events during wartime, the content of LPO end products in
the blood serum tended to increase in individuals with the VV genotype and to decrease in individuals with the AA
genotype.
Conclusion. Analysis of antioxidant protection indicators showed a decrease in superoxide dismutase activity in
children with the VV genotype and a tendency toward an increase in catalase and glutathione peroxidase activity
compared to children with the AA genotype. The indicators of individuals with the AV genotype occupied an intermediate position in quantitative terms. The identified changes in oxidative stress markers indicate an intensification of free radical oxidation processes in the body and certain stresses in the functioning of antioxidant enzymes
that provide primary protection against free radicals. A decrease in superoxide dismutase activity may indicate a
decrease in antioxidant activity.
Key words: children; radioactively contaminated territories; stressful life events; genetic polymorphism of manganese.
Problems of Radiation Medicine and Radiobiology.
2025;30:429-448. doi: 10.33145/2304-8336-2025-30-429-448
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