Distribution of renal SOD3 protein in adult mice. (A) Western blot of total protein (10 μg) from kidney regions probed with antibody against mouse SOD3. Lanes 1, 2, 3, and 4 are medulla (M), proximal tubules (PT), cortex (Co), and total kidney, respectively. (B) Immunohistochemical localization of renal SOD3. Paraformaldehyde-fixed renal sections (5 μm) were prepared from normal mice and incubated with polyclonal SOD3 antisera. Control sections were incubated with antisera preabsorbed with excess SOD3 peptide. (i) Wt kidney; brown labeling is present in the proximal convoluted tubules in the cortex and outer medulla. No SOD3 staining was detected in the inner medulla but was prominent in cortical proximal convoluted tubules (*) near the urinary pole of the glomerulus (g). The muscular renal blood vessel showed prominent staining with anti-SOD3 (BV). (ii) KO kidney; no staining is detected (original magnification, × 280). Objective magnification, × 20.