Exercise causes blood glutathione oxidation in chronic obstructive pulmonary disease: prevention by O2 therapy.

The aim of the present study was to determine whether glutathione oxidation occurs in chronic obstructive pulmonary disease (COPD) patients who perform exercise and whether this could be prevented. Blood glutathione red-ox ratio [oxidized-to-reduced glutathione (GSSG/ GSH)] was significantly increased when patients performed exercise for a short period of time until exhaustion. Their resting blood GSSG/GSH was 0.039 +/- 0.008 (SD) (n = 5), whereas after exercise it increased to 0.085 +/- 0.019, P < 0.01. Glutathione oxidation associated with exercise was partially prevented by oxygen therapy (resting value: 0.037 +/- 0.014, n = 5; after exercise: 0.047 +/- 0.016, n = 5, P < 0.01). We conclude that light exercise causes an oxidation of glutathione in COPD patients, which can be partially prevented by oxygen therapy.