Interruption of the luminal flow in the epididymal duct of the corpus epididymidis in the mouse, with special reference to differentiation of the epididymal epithelium.

The efferent duct or the epididymal duct at the border between the caput and corpus epididymidis was cut or ligated in mice at the following stages: birth, 20 days, and 60 days of age. The epididymal duct of the corpus epididymidis was observed at 60 days of age after neonatal or juvenile operation and 4 weeks after the adult operation. After efferent duct interruption, the epididymal duct in the corpus possessed abundant PAS-positive material with no spermatozoa in the lumen, and the principal cells of the epithelium contained PAS-positive inclusions which were considered to be formed due to absorption of the PAS-positive material secreted by the principal cells in the caput epididymidis. Especially after interruption at the border between the caput and corpus epididymidis in juvenile mice, the epithelium of the epididymal duct in the corpus was much taller with peculiar pale, vacuolated cells. These cells were considered as abnormally differentiated forms of the principal cells. The occurrence of the PAS-positive inclusions and peculiar pale cells varied in frequency according to the level and age of interruption of the epididymal duct. The results suggest that the luminal contents produced in the proximal region of the duct may exert an influence on the differentiation of the principal cells of the epididymal duct.