Changes in distribution and staining reactivity of PAS-positive material in the mouse epididymal duct after efferent...

The distribution of spermatozoa and that as well as the staining reaction of PAS-positive material in the epididymal duct were histologically observed in 60 day-old mice and mice 12 h, 24 h, 2 days, and 7 days after efferent duct ligation at 60 days of age. We divided the mouse epididymal duct into five segments; Segments I, II, and III making up the head of the epididymis, Segment IV the body, and Segment V the tail. The cytoplasm of the principal cells in Segment II was PAS-positive. The lumen of the epididymal duct contained spermatozoa and PAS-positive material in the distal portion of Segment I and other segments distal to Segment I. The lumen in Segments IV and V was distended with abundant spermatozoa and PAS-positive material. After efferent duct ligation, spermatozoa disappeared from the lumen in Segments I, II, and III within 2 days, whereas they took 5 days to pass from Segment IV. As spermatozoa disappeared, the luminal material increased in intensity of the PAS-reaction in the distal portion of Segment I and initial portion of Segment II and Segment IV. Segment I became similar in appearance to Segment II 7 days after the ligation. The findings suggest that the PAS-positive material is produced in the distal portion of Segment I and Segment II and accumulates, in the absence of spermatozoa, at the production site and Segment IV, a storage site of spermatozoa; furthermore, Segment I has the capacity of exerting a Segment II-like function, which becomes distinct after blocking the entrance of the testicular fluid.