CYN induces a reduction in the outer stripe of the outer medulla of the kidney in male animals (control A; CYN 300 μg/kg C), and in sagittal sections (10x), demarcation of the outer stripe is less pronounced in the CYN-exposed (300 μg/kg) than control kidneys (arrows). Tubular epithelial cells (1000x) in the S3 region (control B; CYN 300 μg/kg D) exhibit epithelial atrophy, loss of luminal microvilli, cytoplasmic swelling or glycogen accumulation (colorless areas), and mild anisokaryosis. Hematoxylin and eosin stain used. Size bars, 1000 μm in 10×; 100 μm in 1000×.