Mannose-6-phosphate receptor expression in rat epididymis is altered by the androgenic drug (flutamide)treatment

CARVELLI L; JOFRÉ G; VEIGA V; SARTOR T; SOSA MA

Merlo (San Luis)

Congreso; XXII Annual Scientific Meeting of Cuyo Biology Society; 2004

Sociedad de Biología de Cuyo

The epididymis provides the proper environment for maturation of spermatozoa during their transport through the epididymal duct. Epididymal function and integrity is maintained by normal an-drogen levels, i.e., testosterone and its active metabolite dehydrotestosterone. The epididymal epithelium synthesizes and secretes, among several proteins, important amounts of lysosomal enzymes. In other cell types, the sorting and transport of lysosomal enzymes is regulated by mannose-6-phosphate receptors (MPRs) that recognize this mannosylated residue on the enzyme molecule. Two types of MPRs have been described so far, the cation-depen-dent (CD-MPR) and cation-independent (CI-MPR) mannose-6- phosphate receptor. When the enzyme-receptor system is altered, lysosomal enzymes are mostly secreted to the extracellular medium. We wondered if the secretion of lysosomal enzymes in epididymis is related to MPRs expression. By Western blot analyses, we found that in rat epididymis both MPRs are expressed at levels higher than liver and this expression increases by the treatment with the antiandrogenic drug flutamide. From these results we postulate that the increase of MPRs expression by the treatment may be related to a higher intracellular retention and/or a participation in autophagic processes. Further studies on possible redistribution of MPR and lysosomal enzyme by the treatment are carried out at present.