(A–D) Confocal microscopy identification of Ki67 (green), α-smooth muscle actin (α-SMA, red) and nuclear staining DAPI (blue) in wild type (WT) mouse kidney (A&C) or NOS3-/- (KO) kidney (B&D) following a sham operation (A&B) or UUO surgery (C&D). Quantification of: (E) Ki67+α-SMA+DAPI+ cells/mm2, and; (F) the area of α-SMA and collagen I staining in WT and KO mouse kidney in sham operated and UUO kidneys. (G–N) Confocal microscopy identifying α-SMA (G–J, red) and collagen I (K–N, green) staining in WT (G, H, K and L) or KO (I, J, M and N) mouse kidneys with sham (G, I, K and M) or UUO (H, J, L and N) surgery. Data are mean ±SD from groups of 5 mice and analysis by one-way ANOVA with post hoc analysis with Tukey's multiple comparison test. *p<0.05, ***p<0.001 versus sham operated control.