Morphological and enzymatic study of membrane-bound vesicles from the lumen of the rat epididymis

Abstract

Summary The epithelium of caput and cauda epididymidis of the rat was studied with transmission electron microscopy (TEM) and freeze‐fracture techniques. In thin sections of both zones, the tissue consisted mainly of tall columnar cells (principal cells) with long stereocilia. Clusters of small membrane‐bound vesicles were located in the lumen between or immediately over the stereocilia. Freeze‐fracture replicas also displayed groups of smooth‐surface vesicles in the same location. Membrane‐bound vesicles isolated from the lumen of the rat epididymis were studied by TEM. In thin sections, some of them contained an electron dense material and others looked empty. In addition, the hydrolases: β‐galactosidase, N‐acetyl‐glycosaminidase, α‐mannosidase, aryl‐sulfatase and β‐glucuronidase were detectable in pellets of vesicles treated with Triton X‐100. The results presented here indicate the presence of membrane‐bound vesicles observed by two different methodologies in the rat epididymal fluid and demonstrate five glycosidases in their content.

A Light and Scanning Electron Microscopic Study of the Epididymis Active State of the Endemic Mexican Rodent Peromyscus winkelmanni (Carleton) (Rodentia: Muridae)

“…In P. Winkelmanni , secretory vesicles can be seen in various amounts and types in the three segments of the epididymis. We agree with the suggestion of Fornés et al. (1995) who mentioned that these types of vesicles with diameter of 1.5–3.0 μ m have an important role in sperm maturation due to the presence of glycosidases, which play a significant part in covering the sperm surface with macromolecules such as glycoproteins.…”

“…The function of this organ depends on the secretory products of the epithelial cells of its different regions. The epididymal epithelium produces a complex secretion that covers the spermatozoa during its passage through the epididymis (Bedford, 1994; Cornwall and Hann, 1995; Fornés et al., 1995; Hermo et al., 1999). Furthermore, gonadal steroids regulate the epididymis (Setchell et al., 1994; Hess et al., 1995; Taehkae et al., 1997; Drevet et al., 1998; Kirchhoff, 1999).…”

Compartmentalization of Proteins in Epididymosomes Coordinates the Association of Epididymal Proteins with the Different Functional Structures of Bovine Spermatozoa1

“…These vesicles show structural similarity with exosomes and have a diameter of 50 to 500 nm. Epididymosomes have been described in an increasing number of mammalian species, including human [13], mouse [23], sheep [24,25], rat [12,26], hamster [15,27], and bull [14,28,29]. The content of proteins in epididymosomes is complex in number and electrophoretic behavior [28][29][30].…”

Epididymosomes Role of extracellular microvesicles in sperm maturation

“…Forbes et al (1995) subjected rat epididymal fluid to sucrose gradient centrifugation to separate two populations of membranous vesicles that differed in size and enzymatic composition. With diameters in the micrometer range these vesicles likely differ from epididymosomes, which are characterized by diameters of less than 250 nm as described by a number of laboratories using different animal models (62,63). The existence of extracellular microvesicles has raised great interest during the last decade as a result of their potential roles in cell-cell communication and their possible implication in multiple pathophysiological situations.…”