A) Fluorescent microscopic images of peroxynitrite by HKGreen-4 labeling. HEKn cells were treated with 1 μM AsIII, or co-treated with 100 μM MnTMPyP (SOD mimic), 100 μM c-PTIO (nitric oxide scavenger), 100 μM Uric Acid (UA, peroxynitrite scavenger) for 24 h. Scale bar = 100 μm. B) Statistical summary of fluorescent intensity. AsIII significantly induced peroxynitrite production, which was reduced by scavenging superoxide, nitric oxide, or peroxynitrite. Bar chart shows mean ± SD. *, p < 0.05, n = 6.