Mechanism of the apoptosis of rat pancreas islet β cell strain (INS-1 cells) induced by sodium arsenite / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study mechanism of the apoptosis of rat pancreas islet β cell strain (INS-1 cells) induced by sodium arsenite.</p><p><b>METHODS</b>INS-1 cells were exposed to sodium arsenite at the different concentrations. MTT assay was used to detect the viability of INS-1 cells. The potentials on mitochondrial membrane and lysosome membrane of INS-1 cells were determined with the fluorescence spectrophotometer. The apoptotic levels of INS-1 cells exposed to sodium arsenite were observed by a fluorescence microscope and flow cytometry.</p><p><b>RESULTS</b>After exposure to sodium arsenite, the viability of INS-1 cells significantly decreased with the doses of sodium arsenite. At 24 h after exposure, the OD values of the mitochondrial membrane potentials declined observably with the doses of sodium arsenite (P < 0.01). At 48 h after exposure, the OD values of the lysosome membrane potentials significantly increased with the doses of sodium arsenite (P < 0.01). At 72 h after exposure, the apoptotic cells were observed under a fluorescence microscope and enhanced with the doses of sodium arsenite. The apoptosis cells with light blue, karyopyknosis, karyorrhexis, apoptotic body and chromatin concentration appeared. The results detected with flow cytometry indicated that after exposure, the apoptotic INS-1E cells significantly increased with the doses of sodium arsenite.</p><p><b>CONCLUSIONS</b>The sodium arsenite can induce the apoptosis of INS-1 cells through the mitochondria-lysosome pathway.</p>

Effects of sodium arsenite on catalase in human keratinocytes / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the effects of sodium arsenite on the activity, the mRNA and the protein expression of CAT in human keratinocyte cell line (HaCaT).</p><p><b>METHODS</b>The activity of catalase (CAT) was detected by ultraviolet direct velocity assay. RT-PCR was used to detect the mRNA expression of CAT and Western blotting was conducted to detect the protein expression of CAT.</p><p><b>RESULTS</b>If the cells were treated with higher than 5.0 micromol/L sodium arsenite, the activity, mRNA and protein expression of CAT were decreased significantly and in a dosage dependent fashion (P < 0.05).</p><p><b>CONCLUSION</b>CAT is inhibited by sodium arsenite in the transcription, translation and activity levels.</p>