Tissue distribution, developmental profile and hormonal regulation of androgen-responsive secretory proteins of rat seminal vesicles studied by immunocytochemistry.

The seminal vesicles of the rat synthesise large amounts of androgen-regulated secretory proteins. Indirect immunofluorescence cytochemistry and immunoblotting with monospecific polyclonal antibodies against three of the major secretory proteins (II, S and F) have been used to investigate the tissue distribution, subcellular localisation, androgen-regulation and developmental profile of secretory protein synthesis. There was no evidence for regional specialisation of the seminal vesicle epithelium; every epithelial cell synthesizes all three proteins via a classical secretory involving storage in secretory vesicles. Proteins S and II are contained within the same secretory vesicles. The time course of deinduction of proteins S and F after castration and their reinduction by testosterone closely followed that for their specific mRNAs described previously. During development, proteins S and F first appear between 10 and 15 days after birth. A protein immunologically related to seminal vesicle protein II is present in the lateral and dorsal lobes of the prostatic complex.