OBJECTIVETo investigate the expression of human epididymal secretary protein 2 isoform human epididymal protein 2beta1(HE2beta1) in the testis and epididymis of adolescent male rats along with its significance.

METHODSImmunohistochemical staining was used to detect the expression and localization of HE2beta1 in the testis and epididymis of 15 adolescent SD rats.

RESULTSHE2beta1 immunoreactive staining was detected in the testis and epididymis. In the epithelia of the epididymal duct, HE2beta1 expressed mainly in the supranuclear region of the principle cells and the basement membrane of some epithelial cells; there were no immunostaining in the n clear cells, halo cells and basal cells. The immunopositive reaction was detected, weak in the distal caput, strong in the proximal, middle corpus and the cauda, but negative in the initial segment. Immunopositive results of HE2beta1 were also observed in some of the nuclei of spermatogonia and Sertoli cells with negatively-stained cytoplasm.

CONCLUSIONImmunohistochemical staining is a fairly sensitive method for detecting HE2beta1 expression. The localization and expression level of HE2beta1 in the genital duct of adolescent male rats exhibited a region- and cell-specific expression pattern, which suggests that HE2beta1 may play an important role in spermatogenesis, maturation and epididymal epithelial innate defense mechanisms.