Higher magnification of the proximal efferent ductule epithelium in control (A,C,E) and ICI-treated (B,D,F) males. A, B. Day 12 post treatment showing nearly cuboidal epithelium in control tissue during early puberty but a shortened epithelium in the ICI treated (B). Ci, cilia; Mv, microvilli; V, endocytotic vesicles. C, D. Day 59 post treatment the epithelium has reached it maximum height in control samples (C), however, the height is quite variable between regions. Nuclei (Nu) of ciliated cells are found more apical than the nonciliated cells. Apical cytoplasm of nonciliated cells contained an abundance of PAS-positive granules, previously identified as lysosomes (arrows). Microvilli (Mv) are tall and easily distinguished from the long cilia (Ci). In the ICI-treated ductules, microvilli are short and the nuclei are flattened. E,F. Day 125 post treatment. The control ductule epithelium is columnar (double arrow) and contains numerous PAS-positive granules. In some regions of the ICI-treated group, the epithelium remains severely shortened in height (double arrow). Bar = 50 μm for A, B. Bar = 25 μm for C-F.