Representative histopathological photomicrographs of hematoxylin-stained cross-sections of rat testes. Control group (A, X100), co-enzyme Q10-treated group (B1, X100 and B2, X400), corn oil-treated group (C1, X100 and C2, X400), titanium dioxide nanoparticles-exposed group (D1 and D2, X100 and D3, X400), cadmium-exposed group (E1 and E2, X100 and E3, X400), titanium dioxide nanoparticles and cadmium co-exposed group (F1, X100 and F2, X400), and titanium dioxide nanoparticles and cadmium co-exposed group treated with co-enzyme Q10 (G1, X100 and G2, X400). Acidophilic material (A), blood vessels (BV), cellular vacuolations (star), darkly stained pyknotic nuclei (thin arrow), epithelial vacuolations (star), germinal epithelium (G), giant spermatids (yellow arrow), interstitial edema (E), Leydig cells (LY), mild interstitial edema (E), seminiferous tubules (T), spermatozoa (S), thickened basement membrane (thick arrow), thickened capsule (C), tubular lumen (L), and vacuolation of Leydig cells (green arrow). (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)