engleski

Superoxide dismutase in erythrocytes and leukocytes of asthmatic children

Peripheral blood cells obtained from symptomatic patients with asthma generate increased amounts of reactive oxigen species (ROS), including superoxide radicals (O2.-). The increase correlates with severity of disease. Many of the features of asthma can be indicated by ROS. Reduced antioxidant defenses in the particular patient reported in the whole blood and in peripheral leukocytes contribute to severity of asthma. Protective role of superoxide dismutase (SOD), enzyme which catalyses dismutation of O2.- into molecular O2, is confirmed in oxidative stress which is evident in asthma. We have measured SOD catalytic activity in erythrocytes and leukocytes obtained from normal subjects (healthy adult controls) and patients, asthmatic children (3.5-20 years). The analysis was performed two times on the same patients: during acute exacerbation of asthma (group 1) and 5 days later, when there were no signs of bronchoobstruction (group 2). SOD catalitic activity was measured spectrophotometricaly, by modified method according to Oberlery and Spitz, and expressed in U/g protein for leukocytes and U/g hemoglobin for erythrocytes. SOD catalytic activity in leukocytes was reduced in group 1 when compared to group 2 for 31% (p0.05). No diferences in catalytic activity of SOD in erythrocytes were observed between control subjects and group 1, or control subjects and group 2 of patients. Asthma is more frequently manifested in childhood than in adulthood. One of characteristics of asthma is strong inflammation. Leukocytes play an important role in inflammatory reaction. The finding of reduced SOD catalytic activity in leukocytes, but not in erythrocytes, suggests implication of decreased SOD catalytic activity in inflammation characterizing asthma.

superoxide dismutase; asthma; leukocytes; erythrocytes; children

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