In this study, the effects of sulfur dioxide (SO2) ,a common pollutant in urban air, on t-butyl hydroperoxide-induced oxidative stress in rat lung tissues were examined. Ten young rats and 10 adult rats were exposed to SO2 while another 10 young rats and 10 adult rats made up the control groups. Ten ppm SO2 was administered to the animals of the SO2 groups in an exposure chamber for one hour a day every day for 6 weeks. The control groups were exposed to filtered air in the same chamber for the same period. At the end of the experimental period, the lung tissues were sonicated and the protein concentration was adjusted to 20 mg/dl. Albumin solution of the same concentration was prepared as the blank. Luminol-dependent chemiluminescence was induced by the addition of t-butyl hydroperoxide in the presence of hemoglobin as the catalyst. The maximum chemiluminescence intensities (MCI) and maximum chemiluminescence time (MCT) detected in both the controls and SO2 groups were found to be significantly lower and longer respectively than those of the corresponding albumin group. The MCIs detected in the young and adult rats exposed to SO2 were found to be significantly higher than those of the corresponding control rats. The MCIs detected in the adult rats exposed to SO2 were found to be significantly higher than those of the young rats exposed to SO2. The MCTs of the SO2 groups were significantly decreased in comparison to the respective control groups. It seems that the exposure of lung tissues to SO2 increases susceptibility to oxidative stress in rats. The results of this study also suggest that antioxidant protection in lung tissues may diminish with age.

In this study, the effects of sulfur dioxide (SO2) ,a common pollutant in urban air, on t-butyl hydroperoxide-induced oxidative stress in rat lung tissues were examined. Ten young rats and 10 adult rats were exposed to SO2 while another 10 young rats and 10 adult rats made up the control groups. Ten ppm SO2 was administered to the animals of the SO2 groups in an exposure chamber for one hour a day every day for 6 weeks. The control groups were exposed to filtered air in the same chamber for the same period. At the end of the experimental period, the lung tissues were sonicated and the protein concentration was adjusted to 20 mg/dl. Albumin solution of the same concentration was prepared as the blank. Luminol-dependent chemiluminescence was induced by the addition of t-butyl hydroperoxide in the presence of hemoglobin as the catalyst. The maximum chemiluminescence intensities (MCI) and maximum chemiluminescence time (MCT) detected in both the controls and SO2 groups were found to be significantly lower and longer respectively than those of the corresponding albumin group. The MCIs detected in the young and adult rats exposed to SO2 were found to be significantly higher than those of the corresponding control rats. The MCIs detected in the adult rats exposed to SO2 were found to be significantly higher than those of the young rats exposed to SO2. The MCTs of the SO2 groups were significantly decreased in comparison to the respective control groups. It seems that the exposure of lung tissues to SO2 increases susceptibility to oxidative stress in rats. The results of this study also suggest that antioxidant protection in lung tissues may diminish with age.