[[alternative]]Effects of exercise and cigarette smoking on oxidative stress

[[abstract]]Abstract Purpose: To investigate the effects of oxidative stress induced by one bout of high-intensity exercise on blood oxidative indicators and activities of antioxidative enzymes in subjects with regular exercise and/or with chronic cigarette smoking. Methods: There were four groups (8 subjects for each group) : control group (C group), exercise group (E group), smoking group (S group), and exercise-smoking group (ES group). Subjects performed one bout of high-intensity treadmill exercise ( 85％VO2max ) to volitional exhaustion. Blood samples were collected before and immediately after exercise to analyze plasma lactate, thiobarbituric acid reactive substances (TBARS), oxidized low density lipoprotein (oxLDL), and the activity of antioxidative enzymes in erythrocyte lysate, such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx). Paired t test, independent one way ANOVA and two-way (exercise × smoking) ANCOVA were used for statistical analysis. Results: Except for plasma lactate, which was significantly higher before exercise than after exercise (p < .05). There were no significant differences between time trials in all other indicators. The comparisons between groups were described as follows: GPx activity was significantly higher in ES group than in E group (p < .05), SOD activity was significantly higher in E group, S group and ES group in comparison with C group (p < .05), and was also significantly higher in ES group than in E group (p < .05). CAT activity was slightly higher in E group than in C group, and also in ES group than in S group, but not statistically. Plasma oxLDL in subjects with cigarette smoking (ES group and S group) was significantly higher than nonsmokers (C group and E group) (p < .05). However, plasma TBARS showed no significant differences between groups. Conclusion: These results indicated that regular exercise can increase the activity of antioxidative enzymes. However, chronic cigarette smoking may have an additive effect, aggravated with oxidative stress; and increase the risks of cardiovascular disease. In addition, one bout of high-intensity may not increase oxidative stress on smokers. Keywords: chronic cigarette smoking, regular exercise, antioxidative enzymes