IMMUNOHISTOLOGICAL LOCALIZATION OF CLUSTERIN IN THE MALE GENITAL-TRACT IN HUMANS AND MARMOSETS

Clusterin is a multifunctional protein, first described in the reprodu ctive tracts of the rat and the ram. It is produced by several cell ty pes and exists in at least two differentially glycosylated forms. The aim of this study was to extend knowledge of clusterin expression in t he primate (human and marmoset) male reproductive tracts by means of c lusterin-specific immunohistochemical techniques. In both normal and a bnormal testicular tissue, clusterin was found in association with Ser toli cells, lumenal sperm, proacrosomal Golgi complexes, residual bodi es, and degenerating germ cells. The major differences observed betwee n the two groups were attributable primarily to morphological differen ces rather than to clusterin expression specifically. There was no cor relation between testicular clusterin content and the cause and severi ty of spermatogenic disorders. Within normal epididymides, regional di fferences in clusterin staining similar to those reported in the rat w ere observed. The seminal vesicles contained large amounts of positive clusterin staining, whereas normal human prostate was completely nega tive. Low levels of clusterin expression were observed in the marmoset prostate. This study suggests that clusterin is an important and wide spread product in the human and marmoset reproductive tracts and is li kely to have a role in spermatogenesis.