Oxidative stress caused by activation of NADPH oxidase 4 promotes contrast-induced acute kidney injury
HK-2 cells were cultured to 70–80% confluence, and iohexol was added. Cells were incubated with iohexol at the indicated concentrations for 30 min. For examination of the long-term viability of HK-2 cells after iohexol exposure, medium containing iohexol was removed after 2 h and replaced with fresh serum-free medium for 22 h (2/22 h). (A) The apoptotic response of HK-2 cells was assayed by measuring caspase 3/7 activity. (B) The viability of HK-2 cells was assayed using ATPlite and MTT assays. The data are the mean ± SD (n = 5). **p < 0.01 versus control and ##p < 0.01, ###p < 0.001 versus Iohexol treatment only.