Fig. 7. Histological evaluation of testes and epididymides. (A) Normal testis development in a negative control rat, (B) normal testis development in a non-responder, (C) severe testicular atrophy in a responder, (D) normal epididymis duct in a negative control rat, (E) normal epididymis duct in a non-responder, and (F) severe atrophy of epididymis duct in a responder. SG: spermatogonia, SC: spermatocyte, ST: spermatid, SZ: spermatozoa, LD: Leydig cells.