PASSAGE OF SPERMATOZOA LABELLED WITH THYMIDINE-3H THROUGH THE DUCTUS EPIDIDYMIDIS OF THE RABBIT

Abstract

The duration of spermatozoa transit through the ductus epididymidis, determined by the isotope method, is 9 to 10 days in rabbits at sexual rest. The average duration of transit through each segment of the epididymis is approximately: for the proximal caput epididymidis, 1 day; for the distal caput epididymidis, 2 days; for the corpus epididymidis, 1 day; for the proximal cauda epididymidis, 1 day; for the distal cauda epididymidis, and the ductus deferens, 4 to 5 days. Labelled spermatozoa enter and are transported through the ductus epididymidis in successive waves. These waves correspond to the release into the lumen of the seminiferous tubules, of spermatozoa derived from spermatogonia and preleptotene spermatocytes labelled at the time of isotope injection. A mixing of spermatozoa of different ages occurs in the epididymis by their more rapid transit along the periphery of the duct and by a dilution effect taking place in the distal cauda epididymidis.