engleski

Localization of vacuolar proton ATPase (V-ATPase) along the male reproductive tract in rat

The acid pH of the luminal fluid in the male reproductive tract (MRT) is important for inhibiting sperm motility during storage and for sperm maturation. The cellular mechanisms of proton secretion along the MRT are poorly characterized. As recently reported (Breton et al., Nature Med. 2:470-472, 1996), a V-ATPase may acidify the luminal fluid in the rat epididymis (E) and ductus deferens (DD). The aim of this study was to locate the V-ATPase in all segments of the MRT by immunofluorescence microscopy, Western blotting and measurement of bafilomycin-sensitive ATPase in total plasma membranes (PM) from various MRT segments. A polyclonal anti-peptide antibody against the 31 kDa V-ATPase subunit stained special cells in the rete testis, nonciliated cells in the efferent ducts (ED), apical, narrow and clear cells in the E, scattered cells in the proximal DD, all epithelial cells in various glands of the ampullary and dorsal prostate, but only a few epithelial cells in the ventral prostate (VP). In most V-ATPase positive cells the staining was strongly apical, but the cytoplasm was also stained in most cases. In addition, the perinuclear (Golgi) region in some cells of the seminiferous tubule, ciliated cells of the ED, all cells of the seminal vesicle, and most cells of the VP, was stained. By Western blotting and by ATPase measurement, the V-ATPase was found in total PM from all MRT segments and its relative abundance largely matched the distribution seen by immunocytochemistry. We conclude that the V-ATPase-positive cells reside in most segments of the MRT where they may contribute to proton secretion.

proton pump; acidification; immunolocalization; male reproductive organs; rat

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