Androgens are essential for epithelial cell recovery after efferent duct ligation in the initial segment of the mouse epididymis.

Efferent duct ligation (EDL) induces epithelial cell degeneration followed by regeneration in the epididymal initial segment (IS). We tested here the role of androgens in the recovery phase. EDL was performed at post-natal weeks (PNW) 3, 4, 5, 6, and 7, and apoptotic and proliferating epithelial cells were quantified 24 hours, and at days 2 and 2.5 post-EDL, respectively. A progressive increase in the number of apoptotic basal cells (BCs) and principal cells (PCs) was detected from PNW 3 to 6, 24 hours after EDL. 2 days after EDL, no increase in proliferating BCs and PCs was observed at PNW 3 and 4, despite the induction of apoptosis by EDL. A progressive increase in the number of proliferating BCs was then observed from PNW 5 to 6, while the number of proliferating PCs remained low. 2.5 days after EDL, the number of proliferating BCs and PCs remained low at PNW 3, 4 and 5, but a marked increase in the number of proliferating PCs was observed at PNW6. Flutamide pre-treatment for 3 weeks followed by EDL at PNW7 dramatically decreased the number of proliferating BCs on EDL day 2, and the number of proliferating PCs on EDL day 2.5, compared to controls. We conclude that 1) BCs are the first to show recovery after EDL, followed by PCs; 2) androgens are essential for BC and PC repair after injury in the post-pubertal epididymis; and 3) the pre-pubertal epididymis lacks repair ability following injury.