Oxidative Stress - Chronic Obstructive Pulmonary Disease - page 295

Table 3 Antioxidant Constituents of Plasma and Epithelial Lining Fluid (ELF)

Antioxidant Plasma (mM) ELF (mM)

Ascorbic acid 40 100

Glutathione 1.5 100

Uric acid 300 90

Albumin-SH 500 70

Alpha-tocopherol 25 2.5

b -Carotene 0.4 —

Smoking and exacerbations of COPD result in decreased antioxidant
capacity in plasma in associationwith depleted protein sulfydryls in the plasma
(12,22). The decrease in antioxidant capacity in smokers occurred transiently
during smoking and resolved rapidly after smoking cessation (Fig. 11). In
exacerbations of COPD, however, the decrease in antioxidant capacity
remained low for several days after the onset of the exacerbation, tending to
return towards normal values at the time of recovery from the exacerbation
(22). The depletion of antioxidant capacity could in part be explained by the
increased release of ROS from peripheral blood neutrophils, as shown by a
significant negative correlation between neutrophil superoxide anion release

Figure 11 Plasma antioxidant capacity measured as Trolox Equivalent Antioxi-
dant Capacity (TEAC) in healthy non-smokers and healthy chronic smokers who
have not smoked for 12 hr and smokers who smoked two cigarettes one hour prior
to measurement (acute smoker). p < 0.001 compared with non-smokers. Data are
Mean SEM.