RESUMO
In the pathogenesis of asthma, oxidative stress appears to play an important role and existence of an oxidant/antioxidant imbalance is evident. In this study the key markers of oxidative stress and lipid peroxidation in the pathogenesis of asthma in childhood in comparison to healthy subjects were investigated. Plasma marker of the lipid peroxidation: malondialdehyde (MDA), the erythrocytes antioxidative enzymes: glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glutathione reductase (GR) and cysteine-containing tripeptide glutathione (GSH) were evaluated by spectrophotometric methods using blood samples collected from 37 healthy children and 44 asthmatic patients. The GSH-Px activity was significantly lower in asthmatic children (3.99 +/- 1.0 IU/g Hb) than in healthy controls (4.61 +/- 1.3 IU/g Hb; p < 0.034). Significant difference in activity of the SOD, GR, and concentration of cysteine-containing tripeptide GSH was not confirmed (p > 0.05). Lower GSH-Px activity in children with controlled asthma showed deficient erythrocyte antioxidant defence and evidence of association between oxidative stress and asthma in childhood. Preserved activity of GR and SOD, together with concentration of GSH and MDA, still seems to be crucial in controlling antioxidant/oxidant balance of the disease.
