Figure 1.

Representative histological findings. Hematoxylin and eosin staining of the renal cortex for acute kidney injury (AKI) histology scoring is shown. A: representative section from an anesthesia control animal demonstrating normal histology without evidence of AKI on low magnification (×4). B: section from an animal 4 h after cardiopulmonary bypass with deep hypothermic circulatory arrest (CPB/DHCA) demonstrating moderate AKI with 25–50% of the cortical area affected. C: section from an animal 4 h after CPB/DHCA demonstrating severe AKI with 75–100% of the cortical area affected. D: high-magnification (×20) view of damaged proximal tubules demonstrating proximal tubular dilation (red arrows), epithelial thinning (blue arrows), and epithelial blebs (green arrows). [Adapted with permission from Davidson et al. (35).]