A: Time course of nuclear Nrf2 protein expression in kidneys after FeNTA (5 mg/kg) treatment. Nuclear extracts were made from kidneys of control (saline, SAL) and FeNTA-treated mice at different time points (6, 24, 48 h). A western blot of nuclear extracts stained with an antibody that detects mouse Nrf2 (50 μg protein/lane) is shown. Immunoreactive bands were semiquantified by densitometric analysis. Data were normalized to controls and expressed as mean ± S.E.M. (each group, n = 3 animals). Asterisks (*) represent statistically significant differences (p < 0.05) between control and FeNTA groups. B: mRNA expression of Nrf2 target genes in kidneys 6 h after FeNTA (5 mg/kg) treatment. Total RNA was isolated from control (saline, SAL) and FeNTA-treated mouse kidneys and analyzed by the bDNA assay as described in MATERIALS AND METHODS. Data are presented as mean (percent of control) ± S.E.M. (each group, n = 5 animals). Asterisks (*) represent statistically significant differences (p < 0.05) between control and FeNTA groups.