Figure 2.

(A) Rat testis and excurrent ductal system. (B) Normal DE at age 36 d, surrounded by adipocytes (x100). Seminiferous tubules of testis at bottom left. (C) Normal DE at 36 d (x480). (D) Earliest pathology in DE at age 30 d; spermatocytes sloughed from testis at puberty are present as the round cells in the ductal lumen. There is heavy infiltration of neutrophils confined to interstitial space between the ducts. (x400). (E) EO pathology at 70 d shows severe monocytic inflammation confined to DE (yellow window, x200), completely sparing the testis (x100) (F) Advanced EO pathology at 77 d consists of interstitial fibrosis in DE with monocytic inflammation and necrosis. The seminiferous tubules are devoid of spermatogenic cells or sperm (x100; window: x400) (G) Severe monocytic inflammation of the testis, including multinuclear inflammatory giant cells (arrows in yellow window, x200) surrounded by aspermatogenic tubules; some tubules have giant spermatogenic cells with multiple apoptotic nuclei (arrows in blue window, x400). (x100) (H) Testis in Dazl^def F1 rat: (a) Hypospermatogenesis due to arrested development of round or elongated spermatids (x400); (b) Empty and atrophic DE (x200); and (c) no sperm in epididymis. Note giant apoptotic spermatocytes in lumen of cauda epididymis (arrows, x400).