SO2 inhalation induces protein oxidation, DNA–protein crosslinks and apoptosis in rat hippocampus

Abstract Previous studies provide evidence for the possible neurotoxicity of SO 2 , but little information is available about its mechanisms. In the present study, SO 2 inhalation-induced effects on the protein oxidation, DNA–protein crosslinks and apoptosis in rat hippocampus were studied, by exposing Wistar rats to SO 2 at 14, 28 and 56 mg/m 3 . The results indicate that the protein carbonyl content, an indicator of protein oxidation, and DNA–protein crosslink coefficient were significantly augmented with concentration-dependent properties. In addition, SO 2 inhalation at all concentrations tested caused the increases of caspase-3 activity and number of TUNEL positive staining neuron and the statistical difference was observed after 28 and 56 mg/m 3 exposure, suggesting the occurrence of apoptosis. The results imply that attacking protein, nucleic acids and lipids by free radicals, generated via SO 2 derivatives in vivo , is one of the main mechanisms for SO 2 -induced injuries in central neuronal system.