Postnatal development and regulation of proteins secreted in the boar epididymis

The number of proteins secreted by the boar epididymis increased progressiv ely from 1 mo of age to the adult period. The first specific secretory acti vity was revealed at 2 mo in the distal caput (hexosaminidase, clusterin, a nd lactoferrin) and in the corpus (train O/HE1). Train A and glutathione pe roxidase specific to the proximal caput, and trains E and M specific to the corpus, appeared at 4 mo. At 5 mo, secretion of procathepsin L occurred in the middle caput and that of mannosidase and E-RABP in the distal caput. Approximately 48% of all the proteins secreted in the adult boar epididymis were dependent on the presence of androgens, either stimulated (33.6%) or repressed (14.4%); 47% were modulated by other factors, and 5% were unregul ated. In the proximal caput, 50% of the specific secreted proteins were con trolled essentially by factors emanating from the testis. In more distal re gions, two proteins secreted in the corpus were regulated by factors from t he anterior regions. The regionalization of the secretory activity of the epididymal epithelium resulted in a specific regulation for each protein, which was modulated acc ording to the region of expression and influenced by either testicular or e pididymal factors that remain to be identified.