Effects of castration on specific glycoprotein secretions of the epididymis in the rabbit and hamster.

Mature male rabbits and hamsters were bilaterally castrated and their epididymides were examined, at 2, 4, 7, 9 and 14 days after operation, for the presence of several glycoproteins by using monospecific antisera and indirect immunoperoxidase labelling. In the rabbit, there was a reduction in the glycoprotein reaction product in the epithelium of the proximal caput epididymidis by 2-4 days after castration, and the staining was weak or absent by 7-9 days. Compared with controls, there was also a marked decrease in the intensity of reaction product to glycoprotein in the lumen of the proximal and distal corpus epididymidis 2-4 days after castration although spermatozoa still filled the duct in this region. Glycoprotein was present in the distal cauda epididymidis at 14 days but staining diminished as spermatozoa were cleared from the tract. In the hamster, epididymal glycoproteins were apparently less critically dependent on androgens than those in the rabbit, reaching a weak but constant level in the proximal region by 7-9 days after castration and remaining at the same intensity in the distal cauda epididymidis throughout the study. These results suggest that the secretion of specific glycoproteins by the mammalian epididymis is related to androgen levels and to sperm maturation.