EFFECTS OF CASTRATION ON LYSOSOMAL PROTEINS IN RAT EPIDIDYMIS

CARVELLI L, ; MALOSSI E; AGUILERA AC; BANNOUD N; CROCE C; SOSA MA.

San Juan

Congreso; SECOND JOINT MEETING OF THE BIOLOGY SOCIETIES FROM ARGENTINA; 2011

An important function of mammalian epididymis is the participation in sperm maturation, through the secretory activity. Several proteins are secreted actively by the epididymis (lysosomal enzymes). We here attempted to dilucidate if secretion of cathepsin D (CatD) and prosaposin, (PSAP) in epididymis is a selective process mediated by receptors (sortilin and/or cation-dependent Man- 6-phosphate receptor CD-MPR), and if these mechanisms are regulated by testosterone (Test). Three groups of rats were used; controls, castrated and castrated with hormone replacement (Test). After 48 hs, the epididymides were removed and the three regions (caput, corpus, and cauda) processed separately for the study (immunoblot) of proteins from tissue and the epididymal fluid. A decrease of sortilin expression was induced by castration in the three regions, but only in cauda the effect was partially reversed by hormone replacement, indicating that sortilin is regulated by Test in this zone. In contrast, the CD-MPRs tended to increase due to castration, but hormone replacement did not reverse that effect. In turn, the expression and secretion of CatD tended to increase due to castration and were reversed by the hormone replacement. Meanwhile, PSAP showed no major changes. We conclude that the expression and secretion of CatD in epididymis depend on Test and the increased secretion due to castration could be because a decrease of sortilin and/or a concomitant increase of CD-MPR.