HOCl-mediated loss of cellular viability: Effect of NO. NO was added to cells in EBSS 10 min before HOCl (A) or NO premixed with HOCl (125 μM) for 5 min and then added to cells for 10 min (B). Cells were washed in DMEM, and cellular viability was measured by using the 3-(4,5-dimethyl-2-yl)-2,5-diphenyltetrazolium bromide assay as described in Experimental Procedures. Data are expressed as mean ± standard deviation of six or more separate experiments. *, P < 0.1; **, P < 0.05; and ***, P < 0.01 compared with HOCl addition alone.