Ultrastructure and morphometry of the urethral glands in normal, castrated, and testosterone‐treated castrated male mice

Abstract

Recent studies of the urethral glands in the male mouse and rat have suggested that they are testosterone-dependent glands that may be potential sites for secretory immunity in the male genital tract. In the present study we describe the ultrastructural features of these glands in normal mice and provide quantitative data on the sizes of the acinar cells and their organelles in sham-, oil-, and testosterone-treated castrated mice. Acinar cells in urethral glands from normal mice contain numerous secretory granules, prominent Golgi complexes, elongated mitochondria, and an abundance of rough endoplasmic reticulum (RER) with large and dilated cisternae, all of which are features characteristic of secretory cells. In some acinar cells the cisternae of the RER were filled with closely packed, unbranched, straight, tubular structures that were oriented parallel to one another, that radiated from aggregates of dense material, or that were randomly arranged. In other acinar cells the cisternae of the RER showed a network of branching and anastomosing vesicular-like structures whose limiting membranes were occasionally seen in continuity with the membranes of the RER. Secretory acini showed large, unbranched tubules in the acinar lumen. When cut at right angles the large tubules exhibited a distinct fuzzy outer coat with fine projections radiating outwards. The ultrastructure of the acinar cells and the presence of tubules in the lumen suggests that they are engaged in secretion of a tubular protein. Morphometric analysis of acinar cells in the urethral glands showed that the mean volumes of nuclei, cytoplasm, secretory granules, vacuoles, and mitochondria were significantly reduced in castrated mice in comparison to either normal or testosterone-treated castrated mice. This confirms earlier observations that the urethral glands are targets of testosterone.

The urethral glands of male mice in relation to depletion of secretory granules upon mating

“…The (Parr et al, 1992), but their role in the physiology of the urogenital tract has not been investigated. Electron microscope studies suggest that the acinar cells may be involved in protein synthesis and secretion, since they contain stores of secretory granules and rough endoplasmic reticulum with enlarged cisternae filled with tubular material (Parr et al, 1992(Parr et al, , 1993 (Mayerhofer et al, 1990 (Sprando, 1990). Briefly, 0.9% (w/v) saline was perfused through the heart to clear blood vessels, followed by 3.5% (v/v) Urethral gland secretory acini were selected from histologi¬ cal sections 1 pm thick by lottery (Sinha Hikim et al, 1989) (Weibel, 1979 (Fig.…”

Transforming growth factor‐beta 2 heterozygous mutant mice exhibit Cowper's gland hyperplasia and cystic dilations of the gland ducts (Cowper's syringoceles)

“…Small amounts of stromal and smooth muscle cells surround the periphery of each acinus. A striking feature of bulbourethral glands of hamsters and rats is the large number of secretory vacuoles showing filamentous or reticular texture (Flickinger, 1974; Parr et al. 1993) and prominent Golgi complexes (Parr et al.…”