Oxidative damage of sulfur dioxide inhalation on stomachs and intestines of mice

Effects of exposure to sulfur dioxide (SO2) on levels of thiobarbituric acid-reactive substances (TBARS), levels of reduced glutathione (GSH), and the activities of Cu,Zn-superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were investigated in stomachs and intestines of Kunming albino mice of both sexes. SO2 exposure at different concentrations (22, 56, and 112 mg/m(3)) was administered to the animals of SO2 groups in the exposure chambers for 6 h/day for 7 days, while control groups were exposed to filtered air under the same condition. Our results show that SO2 caused lipid peroxidation and changes of antioxidative status in stomachs and intestines of mice. Exposure to SO2 at all concentrations tested caused significantly the increase of TBARS levels in stomachs and intestines of mice. For the stomachs, activities of these antioxidant enzymes and levels of GSH were significantly unaltered by SO2 at low concentrations, except significant increase of SOD activity in the stomachs of male mice. However, higher SO2 caused the significant increases of CAT activities and the significant decreases of GSH levels and activities of SOD and GPx. For intestines, SO2 at all concentrations tested decreased significantly activities of SOD relative to control animals; SO2 caused the decreases of GPx activities, but only the decreases of GPx activities caused by SO2 exposures at higher concentrations (56 and 112 mg/m(3)) were statistically significant. SO2 at all concentrations tested tended to increase the CAT activities in a dose-dependent manner, but the decreases of CAT activities caused by higher SO2 were significant. SO2 at all concentrations tested decreased significantly levels of GSH in intestines of both sexual mice. These results lead to conclusion that SO2 exposure can caused oxidative damage to stomachs and intestines of mice, and SO2 is a toxic agent to stomachs and intestines of mammals, not only to respiratory system. Further work is required to understand toxicological role of SO2 on multiple or even all organs in human and animal.