LIGHT AND ELECTRON-MICROSCOPIC IMMUNOHISTOCHEMICAL LOCALIZATION OF PROTEIN GENE-PRODUCT-9.5 AND UBIQUITIN IMMUNOREACTIVITIES IN THE HUMAN EPIDIDYMIS AND VAS-DEFERENS

The distribution of protein gene product 9.5 (PCP) and ubiquitin immun oreactivities in the ductuli efferentes, ductus epididymidis, and duct us deferens of humans was studied by Western blot analyses and light a nd electron microscopic immunocytochemistry. PGP immunoreactivity was intense in the ductuli efferentes and weak in the ductus epididymidis and ductus deferens, while ubiquitin immunoreactivity was intense in t he ductuli efferentes and ductus epididymidis and very weak in the duc tus deferens. In the ductuli efferentes epithelium, PCP immunolabeling was observed in the cytoplasm of principal cells, whereas ubiquitin i mmunoreactivity was found in the nucleus and cytoplasm of principal ce lls and ciliated cells. In the ductus epididymidis epithelium, only sc attered cells (mitochondria-rich cells) showed PCP immunoreaction in t heir cytoplasm, whereas ubiquitin immunostaining was detected in the n ucleus and cytoplasm of most epithelial cells, except for the cauda, w here ubiquitin immunolabeling was observed only in the nuclei. The duc tus deferens showed no immunostaining for PGP, and only nuclear immuno reactivity to ubiquitin. The ultrastructural localization of PGP immun oreactivity was in the apical cytosol and microvilli. In addition to t hese locations, ubiquitin immunoreactivity was also found in the nucle us of all cell types and cilia of ciliated cells. Although the distrib ution of PGP and ubiquitin immunoreactivities in humans differs from t hat reported in rats, it seems that PCP and ubiquitinated proteins are secreted into the epididymal lumen in both species.