Mouse kidney histology.

Kidney samples were fixed in 10% formalin, embedded in paraffin, and sectioned to 4 μm thickness. Periodic acid–Schiff–stained (PAS-stained) kidney sections were used for kidney histology. Histological scoring was performed in a blinded manner by the renal pathologist. Assessment of the mesangial and glomerular cross-sectional areas was performed by the operator blinded to the identity of the experimental groups by measuring the pixel counts on an average of a minimum of 10 glomeruli per section under ×400 magnification (Zeiss AX10 microscope). Glomerulosclerosis was graded on a semiquantitative scale (0 to 3+), as follows: 0 (absent), 1+ (involving 1%–25% of all glomeruli sampled), 2+ (involving 26%–50% of glomeruli), and 3+ (involving >50% of glomeruli), as described (17). An average of 25 glomeruli sampled per animal were evaluated.