Photomicrographs of seminiferous tubules of rats from T-30 (A, B and C) and T-60 (D, E and F) groups stained by H.E. (A and B) Slightly (A) and severely (B) damaged tubules show vacuolar spaces (arrows) adjacent to Sertoli cell nuclei with irregular shape (S). In B, intraepithelial spaces (asterisks) due to lack of spermatocytes and spermatids were observed. (C) Lack of germ cells (asterisks) is noted in the basal and adluminal portions. Round (thick arrows) and elongate (thin arrow) spermatids are abnormally positioned in the basal compartment. Note a single Sertoli cell showing dislocated nucleus (S). In the other tubule, the peritubular tissue is intensely folded (white arrows). (D) Slightly altered seminiferous tubule shows vacuolar spaces (arrows) adjacent to Sertoli cell nuclei. Some irregular Sertoli cell nuclei (S) are displaced from their original site. (E and F) The damaged tubules show lack of germ cells (asterisks) in the layers of round spermatids (St, in E), pre-leptotene (PL, in E) and zygotene (Z, in F) spermatocytes. In E, vacuolar spaces (arrows) adjacent to irregular and strongly stained Sertoli cell nuclei (S) are observed. In F, the peritubular tissue is irregularly outlined (arrowheads). Adjacent to this altered tissue, the Sertoli cell nuclei are irregular and displaced from their original site (S). Figs. 2A-2F: ×330.