Figure 5. Hepatic redox states during the first wave of hepatocyte proliferation after partial hepatectomy (PH) in Keap1+/+ and Keap1+/− mice. (A) Liver cryosections prepared from 3 mice per time point per genotype were stained with dihydroethidium (DHE). The DHE was oxidized by hepatic free radicals, which generated 2-hydroxyethidium and ethidium. Ethidium-stained DNA exhibited red fluorescence. Representative photographs of liver sections (400×) were taken using the same contrast and lightness parameters and are shown. (B) Hepatic malondialdehyde (MDA) equivalents were quantified to monitor lipid peroxidation indicative of oxidative stress using a thiobarbituric acid reactive substances (TBARS) assay kit. The data are shown as the means of MDA equivalents (nmol/mg liver) ± SD (n = 3 mice/time point/genotype). Asterisks represent P < 0.05 in comparison between Keap1+/+ and Keap1+/− mice. NL, normal liver.