Effect of DPTTS on normal fibroblasts and fibroblasts from HOCl mice in vitro . (a) Proliferation of normal and HOCl fibroblasts incubated with DPTTS. Cellular proliferation was measured with thymidine incorporation. Results are expressed as percentages of viable treated cells versus untreated cells. (b) Cytotoxic effects of DPTTS. The viability of fibroblasts was determined with Crystal Violet assay. (c) Production of ROS (H2O2) as analyzed spectrofluorimetrically by using H2DCFDA. (d) Intracellular glutathione levels as analyzed spectrofluorimetrically by using monochlorobimane. (e, f) Primary normal and HOCl fibroblasts (three mice per group) were seeded in a 96-well plate in triplicates (2 × 104/well) with various modulators (NAC, BSO, catalase, aminotriazole, DDC) for 12 hours and exposed to DPTTS for 16 hours. Production of ROS (H2O2) (e) and viability (F) were determined as expressed earlier. Results are given as the mean ± SEM of three independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001.