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Causes of increased and decreased superoxide dismutase
Last reviewed: 04.07.2025
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Superoxide dismutase converts superoxide into hydrogen peroxide, i.e. it is one of the primary antioxidants. The presence of superoxide dismutase in the human body allows maintaining the physiological concentration of superoxide radicals in tissues, which ensures the possibility of the human body's existence in an oxygen atmosphere and its use of oxygen as a final electron acceptor.
During myocardial infarction, this enzyme protects the heart muscle from the effects of free radicals formed during ischemia (superoxide dismutase activity in the blood during myocardial infarction is high).
Reference values (norm) of superoxide dismutase (SOD) activity in erythrocytes are 1092-1817 U/g hemoglobin.
The degree of increase in superoxide dismutase is inversely proportional to the activity of the left ventricle and can be used as a marker of myocardial damage.
The activity of erythrocyte superoxide dismutase is increased in patients with hepatitis and decreases with the development of acute liver failure. The activity of superoxide dismutase is very high in patients with various forms of leukemia. In Fanconi anemia, the activity of superoxide dismutase in erythrocytes is reduced and, conversely, increased in iron deficiency anemia and β-thalassemia.
In Down syndrome, excess superoxide dismutase leads to accumulation of hydrogen peroxide in brain tissue. A similar phenomenon occurs with aging, thus explaining the early aging of patients with Down syndrome.
High activity of superoxide dismutase in septic patients is considered an early marker of the development of respiratory distress syndrome.
In kidney disease, the level of superoxide dismutase increases in response to increased formation of free radicals. After hemodialysis, superoxide dismutase activity normalizes or becomes lower than normal due to the development of micronutrient deficiency.
The activity of erythrocyte superoxide dismutase is reduced in rheumatoid arthritis; its level can be used to assess the effectiveness of the treatment.
Superoxide dismutase activity is reduced in patients with a weakened immune system, making such patients more susceptible to respiratory infections and the development of pneumonia.