Blind‐ending tubules and branching patterns of the rat ductuli efferentes

Abstract

The ductuli efferentes of Sprague-Dawley rats were studied by microdissection and microscopic evaluation to document the presence of blind-ending tubules (ductuli aberrantes) and to describe morphological and ultrastructural differences between normally open ductules and blind-ending tubules. The branching patterns of the ductuli efferentes varied considerably between animals. A majority of the animals studied had either six or seven ductuli connected to the rete testis, with some animals having as few as four or as many as eight. Pairs of ductules began merging in the conus vasculosa, ultimately forming a single terminal duct within the capsule of the initial segment epididymidis. In a majority of animals, the junctions were unequally matched and located at various positions within the conus. Blind-ending tubules, found in 60% of the animals, were surrounded by thick connective tissue, and had a smaller diameter (78.7 +/- 1.4 microns) than normal ductules in the conus vasculosa (119.5 +/- 2.1 microns) or the terminus (102.2 +/- 1.5 microns). The lumina of blind-ending tubules were contracted and did not contain sperm. Nonciliated cells in the epithelium of blind-ending tubules contained fewer PAS-positive granules and electron-dense bodies (lysosomes) than nonciliated cells in normal ductules. Consideration of these characteristics will prevent blind-ending tubules from being mistaken for pathological changes in efferent ductules.

Testicular Damage after Exposure to Carbendazim Depends on the Number of Patent Efferent Ductules

“…The EFDs of the testis are a series of ductules that function as a vital link that conducts sperm from the rete testis to the epididymis [5,9,21]. In addition, the seminiferous tubule fluid is actively absorbed by the nonciliated epithelial cells lining the EFDs [2,6,8,11,24].…”

Overview of Male Reproductive Pathology

“…no reports of sperm stasis associated with blind-ending ductules in this species (23) (Figure 12). The incidence of spontaneous sperm atic granulomas causing obstruction of efferent ductules is ver y low but has been obser ved in control rats.…”

“…The ducts are lined by a ciliated cuboidal epithelium and highly coiled. Four to 8 ductules are commonly described in rats (23), whereas the dog typically has 13-15 efferent ductules (26), and humans have 10 -14 efferent ductules (49). Rats have a funnel pattern in which 4 -8 ductules coalesce to a single com mon duct that joins the epididym al duct.…”

The Role of Na+−H+ Exchange in Fluid and Solute Transport in the Rat Efferent Ducts

“…The efferent ducts (ductuli efferentes testis) join the rete testis to the epididymis of mammals (Lewis-Jones et al 1982;Jones & Jurd, 1987;Guttroff et al 1992;Ilio & Hess, 1994). They transport sperm and play an important role in male reproduction by reabsorbing up to 95% of the fluid released with sperm from the testis (Crabo, 1965;Jones, 1980Jones, , 1987Djakiew & Jones, 1983;Jones & Clulow, 1987;Jones & Jurd, 1987;Clulow et al 1994), resulting in an increase in concentration of sperm which is critical for their maturation and storage in the epididymis.…”