In this study, activities of superoxide dismutase (SOD), glutathione peroxi
dase (GSH-Px), and catalase (CAT) enzymes were measured in the erythrocytes
, and levels of thiobarbituric acid-reactive substances (TBARS) and antioxi
dant potential (AOP) values were measured in both erythrocyte and plasma sa
mples from smokers and nonsmokers. No significant differences were observed
in erythrocyte parameters, serum triglycerides, and total cholesterol. AOP
was significantly lower and TEARS level higher in the plasma samples from
smokers compared with those of nonsmokers. Results suggest that smoking cau
ses no impairment in the enzymatic antioxidant defense system and does not
lead to oxidant stress in the erythrocytes, possibly because these cells ha
ve potent antioxidant defense capacity.