Levels of sulfite in three organs from mice exposed to sulfer dioxide

To study whether sulfur dioxide (SO2]) can enter into the different organs of mice exposed to SO2, the sulfite contents in brains, hearts, and lungs from male mice were determined by high-performance liquid chromatography with fluorescence detection (HPLC-FD). After reduction and precolumn derivation of tissue homogenates of brains, hearts, and lungs from mice, the mixture was centrifuged, and 5 mu l of the resulting supernatant was directly injected into HPLC; the mobile phase consisted of methanol - phosphoric acid ( 12: 88, v/v), and for the fluorescence detection lambda(EX) 392 nm and lambda(EM) - 479 nm were used. The standard curve was linear in the range from 0.126 mu g/ml to 126 mu g/ml; the minimal detectable concentration was 0.04 mu g/ml (S/N = 3), the average methodological recoveries were from 97% to 101%, and the within-day and between-day precisions were less than 9%. These results showed that sulfite contents in all organs tested from mice in the SO2-exposed groups were significantly increased ( p <.05) in a dose-dependent manner ( r >.92) compared with the control groups. These results indicated SO2 could transform into sulfite in vivo after inhalation, and could distribute into lung and other organs such as brain and heart. These results offered a support for the viewpoint that SO2 is a systemic toxic agent.