Blood antioxidant status and urine sulfate and thiocyanate levels in smokers.

Erythrocyte and plasma antioxidant enzyme activities and antioxidants as well as concentrations of total sulfate and thiocyanate were estimated in a group of healthy subjects and three groups of smokers (cigarette smokers, mixed tobacco smokers, and miscellaneous tobacco smokers). Plasma vitamin E, uric acid, ascorbic acid, ceruloplasmin, and urinary total sulfate concentrations were decreased, whereas dehydroascorbate and urinary thiocyanate concentrations were elevated in the three groups of smokers in comparison to the corresponding levels of the control subjects. On the other hand, erythrocyte superoxide dismutase and catalase as well as plasma superoxide dismutase activities were elevated in subjects of the three groups of smokers compared with the corresponding activity in subjects of the control group. Plasma catalase activity is statistically unaffected by smoking, but blood glutathione peroxidase activities were decreased in the three groups of smokers in comparison with the corresponding levels of the control group. There were also statistically meaningful differences between mean values of the antioxidant concentrations and the activities of the antioxidant enzymes in most of the smokers groups.