Oxidative stress on spleens of mice exposed to sulfur dioxide

Objective To investigate the effects of sulfur dioxide (SO 2) exposure on spleen lipid peroxidation (LPO) and antioxidant status in both female and male mice. Methods After the mice in four experiment groups inhaled the gas of SO 2 four hours daily for seven days and those in control groups received fresh air in the same time, the level of glutathione (GSH), the content of malondialdehyde (MDA), and the activities of glutathione peroxidase (GSH Px) and superoxide dismutase (SOD) in spleens were measured respectively. Results (1) 28 mg/m 3 of SO 2 exposure, though markedly increasing spleen GSH level, made no effects on LPO, GSH Px activity and Cu,Zn SOD activity. With the rise of SO 2 concentration (112 mg/m 3), SO 2 exposure caused the significant elevation in spleen MDA levels and led to the significant reduction in GSH level, GSH Px and Cu,Zn SOD activity, suggesting there might be dose effect relation to some extent. (2) There were no significant differences in the alteration of spleen LPO and antioxidant enzymes between female and male mice exposed to SO 2. Conclusion These results reveal that above 112 mg/m 3 of SO 2 inhalation in short time (about 7 days) can enhance lipid peroxidation in the spleens and influence the antioxidant enzymes, indicating the toxicology of SO 2 may be involved with inducing excessive free radicals in the organs of mice.