Oxidative stress is considered to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). The importance of antioxidant defences in lung disease has been focused on glutathione metabolism. The aim of this study was to evaluate the plasmatic reduced glutathione levels and erythrocyte glutathione reductase activity in patients with stable COPD.
20 patients (mean age 71,30 ± 7,68 years) with stable COPD were studied. 43 healthy non-smokers having no history of lung disease were used as control group. The levels of plasma reduced glutathione were assayed using the quantification of non-protein sulphydryl groups in COPD patients and controls. The enzymatic antioxidant defences were evaluated by assessing the level of erythrocyte glutathione reductase activity in COPD patients and control group.
Our results showed a decreased in plasmatic non-protein sulphydryl groups in COPD patients (0,135 ± 0,023 μmol/mL) compared with controls (0,279 ± 0,010 μmol/mL). Erythrocyte glutathione reductase activity in COPD patients (60,683 ± 4,350 UI/g Haemoglobin) were higher than those in control group (42,143 ± 1,970 UI/g Haemoglobin).
The decrease in non-enzymatic antioxidant and the increase in antioxidant enzyme activity associated to COPD may be regarded as an induced compensatory adaptative response to the accumulation of reactive oxygen species in patients with COPD.
Our results show a disturbance in oxidant/antioxidant status in COPD. This could provide therapeutic implications in the future.
Cristina Cristóvão, No Financial Disclosure Information; No Product/Research Disclosure Information