Animals in the free quercetin treated group, showed no tubular, but two animals exhibited hyperplasia of tubular epitheliocytes and formation of protein casts, and one other animal in the group showed cellular infiltrates predominantly consisting of lymphatic and plasma cells (Table 2). Periodic Acid-Schiff (PAS) histochemical staining identified glomerulosclerosis in all animals, focal hyalinosis in one, and in two animals, edema, thickening, and fibrosis of glomerular basal membranes, sclerosis, and hyalinosis were detected (Figures 8).