Morphology of the bovine epididymis

The epididymis of the bull was divided into six regions, and morphological differences between regions were studied. The epithelium of all regions contained four cell types: principal and basal epithelial cells, and intraepithelial lymphocytes and macrophages. The epithelium of regions II-V also contained a few apical cells. Principal cells of all regions possessed an endocytotic apparatus including stereocilia underlain by canaliculi, coated vesicles, and subapical vacuoles (up to 1 micron in diameter); however, large vacuoles with a flocculent content and multivesicular bodies (up to 5 microns in diameter) were most numerous in regions II, III, and IV. The unique features of principal cells of region I were the presence of well-developed Golgi bodies, few lipid droplets, and whorls of smooth endoplasmic reticulum in the supranuclear cytoplasm. Numerous mitochondria, distended cisternae of rough endoplasmic reticulum, and dense granules characterized the infranuclear cytoplasm of the principal cells of regions II-VI; however, these features were more developed in region V. Apical cells were characterized by the apical location of the nucleus, many mitochondria in the apical cytoplasm, and few microvilli at the luminal border. Basal cells with few cytoplasmic lipid droplets were present throughout the length of the epididymis but appeared more numerous in region V. Intraepithelial lymphocytes were present at all levels of the epithelium but were never seen in the lumen. Intraepithelial macrophages containing heterogeneous granules, eccentric nuclei, and pseudopods were invariably seen near the basal area of the epithelium in all regions. These observations are discussed in an effort to define the role of each cell type in the epididymal epithelium.     

Transcytosis in the epididymis studied by local arterial perfusion

Summary The transport of protein across the cells of the epididymal epithelium was studied using horseradish peroxidase. Transient vascular perfusion of the epididymis of the rat and golden hamster was achieved by pulsatile retrograde infusion into the testicular artery. Peroxidase was found in the interstitium and in the epithelium, located in vesicles, vacuoles and multivesicular bodies of principal, clear and apical cells. Similar findings were obtained in mice after systemic injection of the tracer. In the rat, discharge to the lumen was confirmed by the appearance of enzyme activity in luminal fluid from the caput epididymidis after local injection. The extent of transport amounted to no more than what has been considered leakage in physiological experiments, and the time-course of appearance complemented that found by electron microscopy. The level of transcytosis after pulsatile administration of peroxidase in vivo, as judged from the occurrence of tracer in the epithelium, was much less than that obtained during constant immersion in vitro. The protein was present in multivesicular bodies of principal cells and in vesicles of clear cells at short times after presentation in vitro, when it could not have arrived by endocytosis from the lumen. This suggests that routing of basal endocytic vesicles to the lysosomal apparatus occurs.     

Morphological features of the epididymal epithelium of gerbil, Meriones unguiculatus

Principal cells of the ducts epididymis of the Mongolian gerbil showed ultrastructural characteristics of lining epithelium cells close related to processes of protein secretion, and transcytosis occurring between adjacent principal cells which were mainly verified in the initial segment. Principal cells also presented roles of fluid phase and adsorptive endocytoses, as well as autophagic and heterophagic lysosomal activities mainly observed in the caput epididymis. Columnar (principal) cells of the corpus epididymidis presented great number of variable vesicles and vacuoles distributed in all the cytoplasmic levels occurring a progressive coalescence pattern among them, which help to guarantee formation of cytoplasmic channels for fluid phase transport between the tubular lumen and epididymal interstitium. Clear cells were presented in the initial segment and predominately in the cauda epididymis epithelium of the gerbil and showed marked ultrastructural characteristics of endocytosis activities occurrence, perhaps directly related to the turnover of fluid phase of spermatozoa stored into the lumen of the distal tail. Other epididymal epithelium cells were verified and described such as basal, halo, apical and dark cells, but they did not presented special ultrastructural features.     

Cytochemical and ultrastructural characteristics of the lining epithelium of the distal part of the epididymis in hamsters (Mesocricetus auratus)

In the terminal segment of the hamster epididymidis there was some evidence of micro-merocrine protein secretion a the level of the principal cells and clear evidence of granular secretion in the light cells, presumable of glycoproteins. The PAS and protein cytochemistry reactivities observed in both these cells, of the ductus epithelial lining, but especially in the light cells, are suggestive of mucopolysaccharides and protein complexes synthesis and secretion. This secretion is carried out to the epididymal epithelium from the lumen and luminal content. A complex of small vacuoles and vesicles appeared to form from the Golgi complex is showed in the principal cells. It was suggested that this complex may represented merocrine secretory vacuoles and vesicles in these cells. Dense granules, at the TEM level, are observed in all the cytoplasm of the light cells, with correspondence to similar PAS-positive granules observed in these cells, at the light microscope level. These granules, at the TEM level, are actually secreted to the epididymal duct lumen, by the apical cytoplasms of the light cells. Signs of absorption were suggested to the principal and light columnar cells through the ultrastructural observations of micropinocytosis, apical multivesicular bodies or great membrane-bounded vacuoles in the adluminal cytoplasms.     

Ultrastructural changes in cauda epididymidal epithelial cell types of Azadirachta indica leaf treated rats

To assess if cauda epididymis is a target for the effect of A. indica leaves, Wistar strain male albino rats were administered (po) A. indica leaves (100 mg/rat/day for 24 days). Transmission electron microscopic analysis revealed that in the cauda epididymal epithelium the nuclei of principal cells were enlarged and the number of coated micropinocytotic vesicles of the apical cytoplasm decreased. Microvilli were missing and mitochondrial cristae and Golgi complex were highly disrupted. The cytoplasm was abounding with lysosomal bodies. The clear cells increased in perimeter and their nuclei increased in size and contained lesser chromatin. The nuclear membrane bulged out. The cytoplasm was vacuolized. Further, there was decrease in size of the lipid droplets, mitochondria, Golgi complex, endoplasmic reticulum and there was accumulation of lysosomal bodies. The changes in the principal and clear cells appear to be due to the effect of the hypoandrogen status caused by treatment with A. indica leaves and a direct action on the epididymal epithelium.     

Histochemical localization of zinc ions in the epididymis of the rat

Summary In the present study, the autometallograpic zinc sulphide technique, an improved version of the original Timm sulphide-silver method, was used. This technique reveals a particular pool of ionic zinc that is chelatable by diethyldithiocarbamate. At the light microscopical level, no reaction for zinc was found in tissues of young prepubertal rats. In adult mating and non-mating rats low zinc staining was found in the head and intermediate epididymis whereas the tail of the epididymis demonstrated high levels of zinc ions. Sections from the epididymal tail revealed a compartmentalization, based on pronounced differences in staining intensity along the epididymal ducts. At higher magnification zinc ions were found in the apical part of the principal cell and in the lumen. At the ultrastructural level autometallographic grains were located in vesicles and in lysosome-like structures of the apical parts of the principal cells. The luminal grains were found either associated with sperm cells, with the surface of the large microvilli (stereocilia), or free in the seminal fluid. The variation in content of zinc ions in the epididymal epithelium and lumen suggests that zinc ions are secreted into the lumen from the epididymal tail and may somehow be involved in maturation of the sperm cells.     

Ethylene dimethane sulfonate (EDS) ablation of Leydig cells in adult rat depletes testosterone resulting in epididymal sperm granuloma: Testosterone replacement prevents granuloma formation

Sperm granuloma may develop in the epididymis following vasectomy or chemical insults. Inflammation due to sperm granuloma causes abdominal and scrotal pain. Prolonged and persistent inflammation in the epididymis due to sperm granuloma may lead to infertility. Extravasation of germ cells into the interstitium of epididymis following damage of the epididymal epithelium is one of the primary reasons for sperm granuloma-associated pathology. Since testosterone is vital for the maintenance of epididymal epithelium, we investigated the pathology of sperm granuloma and its relationship with testosterone. Adult rats were treated with a Leydig cell-specific toxicant ethylene dimethane sulfonate (EDS) to eliminate testosterone. At 7 days post-EDS, disrupted epididymal epithelium and sperm granuloma were observed in the caput epididymis. Sperm granuloma and caput were collagen-filled indicating fibrosis. Numerous round apoptotic cells were localized inside the caput lumen and dispersed through the sperm granuloma. Tnp1 (round spermatid marker) was significantly higher in the epididymis of the EDS-treated group compared to controls suggesting the apoptotic cells were round spermatids. Increases in CD68⁺ macrophages and T cells (CD4 and CD8) support an inflammatory immune infiltration in post-EDS epididymis. However, testosterone replacement following EDS prevented the sperm granuloma-associated pathology. We suggest that the immune response in the sperm granuloma may be due to the increased numbers of apoptotic round spermatids or other testicular tissue components that may be released, in addition to the regression of epididymal epithelium due to testosterone loss. Thus, testosterone replacement prevents EDS-induced sperm granuloma and ameliorates sperm granuloma-associated pathology.     

Ultrastructure of crystalloid inclusions in the dog and rat epididymis

Fine structural studies of the epididymis of mature mongrel dogs and of Sprague-Dawley rats were undertaken in conjunction with research dealing with the effects of vasectomy upon this organ. This paper reports the observation of crystalloid and lamellar inclusions present in these species following fixation of the epididymis in 5 % glutaraldehyde, post-fixation in osmium, and routine processing for electron microscopy. In the dog, crystalloid inclusions were observed within the cauda epididymidis of unoperated and vasectomized animals. They were found within the apical cytoplasm of principal cells in association with the Golgi apparatus and endoplasmic reticulum, and in some instances, in close proximity to the nucleus. These crystalloids exhibited a 12 nm periodicity and often measured over 3 μm in length. In the rat, two types of inclusions were found, one within mitochondria of clear cells from unoperated animals and another within membrane-bound bodies of principal cells from the caput epididymidis of unoperated and vasectomized animals. The mitochondria which contained inclusions were basally located and were observed in stacks of up to eight elongate mitochondria each. The mitochondrial inclusions exhibited a complex lamellar structure with an approximate periodicity of 36 nm. In contrast, the crystalloid inclusions found within principal cells were sequestered within supranuclear cytoplasmic bodies which increased in number with age. Such crystalloids exhibited a linear periodicity of 11–13.5 nm, but the precise lattice structure remains to be determined. Although certain aspects of the morphology of these bodies suggests a relationship to microbodies, we have been unable to demonstrate catalase activity within them. At present, neither the origin of crystalloid structures described, nor their relationship to epididymal physiology is clear.     

Ultrastructural and biochemical seasonal changes in epididymal corpus and cauda of viscacha (Lagostomus maximus maximus)

The reproductive and adaptative behavior of wild rodents is synchronized primarily by the photoperiod. The viscacha, a South American rodent of nocturnal habits and seasonal reproduction is photoperiod‐dependent and its reproductive behavior is regulated by the retinohypothalamic‐pituitary pineal axis. Adult males exhibit an annual reproductive cycle with periods of maximum gonadal activity (summer‐early autumn) and gonadal regression (winter). The corpus and the cauda, the most sensitive segments of the epididymis to changes induced by the photoperiod, were analyzed using electron microscopy and enzymatic biochemistry. During gonadal regression, principal and clear cells showed signs of involution with respect to the activity period. These were characterized by more irregular nuclei, smaller cytoplasms, large vacuoles, altered mitochondria, and glycogen deposits. All cellular populations of the epididymal epithelium in regression presented abundant lysosome‐like dense bodies during the active period. In addition, we measured the activity of four acid glycosidases in the cauda epididymis along the reproductive cycle. N‐acetyl‐β‐D‐glucosaminidase (NAG), an enzyme that degrades endocytosed substances from the epididymal lumen, increased significantly during gonadal regression relative to the active period. These results demonstrate that the viscacha epididymis exhibits significant ultrastructural and biochemical changes during the reproductive cycle. We demonstrate that during regression, melatonin secretion in viscacha increases. This study shows that the epididymal epithelium is reduced. Thus, we postulate that the changes observed in the epididymis are modulated by pineal melatonin. Despite these changes, the epididymis might maintain a microenvironment suitable for the survival of stored spermatozoa. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.     

Regional differences in the morphology of the goat epididymis: a light microscopic and ultrastructural study

The goat epididymis, based on morphological differences, was divided into five regions; regions I and II, and the proximal part of region III constituted the head; the distal part of region III and region IV, the body; and region V, the tail. The epithelium of all regions contained principal and basal epithelial cells and intraepithelial lymphocytes and macrophages. In addition, regions II to IV also contained a few apical cells. Clear cells were absent. The epithelium varied in height from the tallest in region I (88 +/- 33 microns) to the shortest in region V (38 +/- 5 microns). Conversely, the luminal diameter, thickness of smooth muscle wall, and luminal sperm concentration were highest in region V. The irregular epithelial height of regions I and IV accounted for a stellate lumen in contrast to the oval lumen of the other regions. Whereas the lumen of region I contained only a few sperm, those of regions II, III, and IV were filled with sperm. Principal cells were the only cell type that showed striking cytological differences between regions. While they contained absorptive features (canaliculi, pinocytotic and coated vesicles, and subapical vacuoles) in all regions, the principal cells of region II were filled with large, heterogeneous vacuoles (up to 5 microns in diameter), suggesting that they may be preferentially involved in transporting and digesting particulate material. Besides absorptive features, principal cells of all regions contained morphological correlates of protein synthesis such as highly developed Golgi complexes in the supranuclear area and numerous cisternae of RER near the Golgi body and in the infranuclear cytoplasm. The cisternae of RER were more developed in region IV, and in some instances, they were distended with flocculent material resembling newly synthesized protein. Unlike the protein synthesizing organelles, principal cells of all regions lacked morphological correlates of steroid hormone synthesis. These results are compared with previously published data on the regional differences in the epididymis of other species, especially with those of the rat and the bull, in an effort to understand the significance of the epididymis in sperm maturation.     

Excurrent duct system of the male turtle Chrysemys picta

The epididymis and efferent duct system of the turtle Chrysemys picta were examined. Seminiferous tubules are drained by a series of ducts that form a rete exterior to the tunica albuginea. The rete is located lateral to the testis and consists of anastamosing tubules of varying diameters, lined by a simple epithelium consisting of squamous to cuboidal cells. The rete is highly vascularized. A series of tubules (efferent ductules) connect the rete to the epididymis proper. The efferent ductules are highly convoluted, running between the epididymal tubules and are of varying diameters. The simple columnar epithelium lining these tubules possesses tight junctions, with every third or fourth cell possessing long cilia that protrude into the lumen. The cytoplasm of these epithelial cells contains abundant mitochondria. In the central portion of the efferent ductule, epithelial cells possess granules that appear to be secreted into the lumen by an apocrine process. The epididymis proper is a single, long, highly convoluted tubule that receives efferent ductules along its entire length. It is lined by a pseudostratified epithelium containing several cell types. The most abundant cell (vesicular cell) lacks cilia, but has a darkly staining apical border due to numerous small vesicles immediately beneath the luminal membrane. The small vesicles appear to fuse with each other basally to form larger vesicles. These cells appear to have an absorptive function, and occasionally sperm are embedded in their cytoplasm. The second-most abundant cell is a basal cell found along the basement membrane. The number of these cells fluctuates throughout the year, being most abundant in late summer and early fall. A small narrow cell with an oval nucleus and darkly staining cytoplasm, extending from the basement membrane to the apical surface, is present in small numbers, particularly in the caudal regions of the epididymis. This cell is frequently found in association with another narrow cell having a rounded nucleus and abundant mitochondria in its cytoplasm.     

Ultrastructure of the perfused rat epididymis: Effect of luminal sodium ion concentration

Summary The appearance of the rat epididymal epithelium changed when it was perfused in vivo through the lumen with unphysiologically high sodium ion concentrations; dilatation of intercellular spaces (ICS) at threshold concentrations of 30mM-Na⁺ in the cauda and about 55mM-Na⁺ in the corpus was associated with absorption of water from the lumen. Despite the distended ICS, junctional complexes appeared intact, and their integrity was confirmed by the exclusion of luminal horseradish peroxidase (HRP) from the ICS, and by demonstrating that circulating [³H]inulin did not enter the lumen. Smooth ER and lipid droplets in the principal cells of the corpus epididymidis were well maintained, and the preservation of granular ER in principal cells of the cauda epididymidis lent morphological support to the continued secretion of protein in this segment. However, occasional distension or involution of inner Golgi cisternae was evident in principal cells after 3–6 h perfusion. In contrast to multivesicular bodies of principal cells, the apical and basal vacuoles characteristic of clear cells changed in size with different perfusing solutions. When low Na⁺ concentrations were perfused large translucent vacuoles were frequently found in the apical cytoplasm of clear cells in the corpus and cauda epididymidis, and filled vacuoles became larger and showed a decrease in content density in the cauda epididymidis. These large vacuoles were absent from tissue perfused with high Na⁺ concentrations. Normal pinocytotic activity of both cell types was demonstrated by perfusing HRP which was taken up by the normal route in principal cells, with some transfer to the Golgi cisternae. By far the most HRP was accumulated in clear cell vacuoles irrespective of the composition of the perfusing solution.     

Observations on the anterior testicular ducts in snakes with emphasis on sea snakes and ultrastructure in the yellow‐bellied sea snake,Pelamis platurus

The anterior testicular ducts of squamates transport sperm from the seminiferous tubules to the ductus deferens. These ducts consist of the rete testis, ductuli efferentes, and ductus epididymis. Many histological and a few ultrastructural studies of the squamate reproductive tract exist, but none concern the Hydrophiidae, the sea snakes and sea kraits. In this study, we describe the anterior testicular ducts of six species of hydrophiid snakes as well as representatives from the Elapidae, Homolapsidae, Leptotyphlopidae, and Uropeltidae. In addition, we examine the ultrastructure of these ducts in the yellow‐bellied Sea Snake, Pelamis platurus, only the third such study on snakes. The anterior testicular ducts are similar in histology in all species examined. The rete testis is simple squamous or cuboidal epithelium and transports sperm from the seminiferous tubules to the ductuli efferentes in the extratesticular epididymal sheath. The ductuli efferentes are branched, convoluted tubules composed of simple cuboidal, ciliated epithelium, and many species possess periodic acid‐Schiff+ granules in the cytoplasm. The ductus epididymis at the light microscopy level appears composed of pseudostratified columnar epithelium. At the ultrastructural level, the rete testis and ductuli efferentes of P. platurus possess numerous small coated vesicles and lack secretory vacuoles. Apocrine blebs in the ductuli efferentes, however, indicate secretory activity, possibly by a constitutive pathway. Ultrastructure reveals three types of cells in the ductus epididymis of P. platurus: columnar principal cells, squamous basal cells, and mitochondria‐rich apical cells. This is the first report of apical cells in a snake. In addition, occasional principal cells possess a single cilium, which has not been reported in reptiles previously but is known in some birds. Finally, the ductus epididymis of P. platurus differs from other snakes that have been studied in possession of apical, biphasic secretory vacuoles. All of the proximal ducts are characterized by widening of adjacent plasma membranes into wide intercellular spaces, especially between the principal cells of the ductus epididymis. Our results contribute to a larger, collaborative study of the evolution of the squamate reproductive tract and to the potential for utilizing cellular characters in future phylogenetic inferences. J. Morphol. 2012. © 2011 Wiley Periodicals, Inc.     

Protein transport to the epididymal lumen

Summary Experiments were performed to clarify the debate over the entry of circulating proteins into the epididymal lumen by use of the marker horseradish peroxidase (HRP). Epididymal tubules from the caput epididymidis of the rat were immersed in medium TC 199 containing HRP (3.5 mg/ ml) for 5 min to 3 h at 33° C. Sections were examined for the presence of tracer within the epithelial cells by electron microscopy. From 5 min to 3 h, vesicles containing peroxidase reaction products were found throughout the cytoplasm of the principal cells. Vesicles occurred close to both the basal and apical membranes, and many were found opening into the interstitial space and lumen, depending on the length of incubation. By 5 min labelled vesicles were infrequently found in the apical part of the cells. Reaction product was observed in the epididymal lumen adhering to the microvilli from 30 min of incubation onwards. At all periods of incubation peroxidase was present at the base of the epithelium and between the cells, but it was never found within the tight junctional complexes, and no reaction deposits were found within epithelial cells of tubules incubated in the absence of peroxidase. It is concluded that large molecules leaving the capillaries may enter the epididymal lumen in the caput by means of fluid-phase endocytosis.     

Morphology of the epithelium of the extratesticular rete testis, ductuli efferentes and ductus epididymidis of the adult male rabbit

The fine structure of the epithelium lining the extratesticular rete testis, ductuli efferentes and ductus epididymidis of the rabbit has been investigated. In the ductuli efferentes the epithelium is composed of two cell types, principal cells and ciliated cells. The latter type is distinguished from principal cells by the presence of cilia projecting into the lumen and the position of the nucleus in the apical half of the cell. Principal cells in this segment are characterized by micropinocytotic vesicles on the surface plasma membrane and a variety of small dense bodies scattered throughout the cytoplasm. In the ductus epididymidis basal cells replace ciliated cells as the second cell type, but differences between various segments of the epididymis are related to the fine structure of the principal cells. In the proximal caput epididymidis (Nicander's region 1) the principal cells are tall with long microvilli. They typically contain a small Golgi apparatus and a cluster of dense bodies adjacent to the nucleus. In the distal caput epididymidis (Nicander's regions 2-5) the apical cytoplasm of principal cells is filled with numerous micropinocytotic vesicles and large multivesicular bodies; these features are interpreted as signs of absorptive activity. The multivesicular bodies are absent from the cytoplasm of principal cells in the corpus epididymidis (Nicander's region 6) and, instead, numerous elements of smooth endoplasmic reticulum, a large Golgi apparatus, lipid droplets and dense bodies characterize principal cells in this segment. Towards the proximal cauda epididymidis (Nicander's region 7), the number of dense bodies (lysosomes) in the cytoplasm increases considerably. In the globose cauda (Nicander's region 8), the principal cells are reduced in height, and in addition to the features described in region 7, are characterized by a concentric array of rough endoplasmic reticulum in the basal cytoplasm. These observations are discussed in relation to the role of the epididymis in promoting the maturation and survival of spermatozoa.     

Immunolocalization of a 25-kilodalton protein in mouse testis and epididymis.

We have recently observed that a polyclonal antibody raised against a mouse epididymal luminal fluid protein (MEP 9) recognizes a 25-kDa antigen in mouse testis and epididymis [Rankin et al., Biol Reprod 1992; 46:747-766]. This antigen was localized by light and electron microscopic immunohistochemistry. The immunoreactivity in the testis was found in the residual cytoplasm of the elongated spermatids, in the residual bodies, and in the cytoplasmic droplets of spermatozoa. In the epididymis, the epithelial principal cells were stained from the distal caput to the distal cauda. Immunogold labeling in the principal cells showed diffuse distribution without preferential accumulation in either the endocytic or the secretory apparatus of the cells. In the epididymal lumen, the immunoreactivity was restricted to the sperm cytoplasmic droplets. No membrane-specific labeling was observed in luminal spermatozoa, cytoplasmic droplets, or isolated sperm plasma membranes. Three weeks after hemicastration or severance of the efferent ducts, a normal distribution of the immunoreactive sites was found in the epididymis. Immunoreactivity, was also detected in the epididymal epithelium of immature mice as well as in that of XXSxr male mice having no spermatozoa in the epididymis. These results suggest that the immunoreactivity seen in the principal cells originates from synthesis rather than endocytosis of the testicular protein from disrupted cytoplasmic droplets. Furthermore, these results suggest that the 25-kDa protein is synthesized independently by both testis and epididymis.     

Ultrastractural features of the principal cell in the epididymis of the rhesus monkey

The ultrastructural features of the principal cell in the epididymal epithelium of the monkey epididymis are suggestive of the cell carrying out a dual function of absorption and secretion. Both these functions occur on the luminal surface of the cell as well as on the lateral and basal aspects of the cell which face the intercellular spaces. Transmision Electron Microscopic studies of epididymal tissues following their impregnation with lanthanum nitrate indicated that the intercellular spaces are effectively sealed-off from the luminal space by the apically situated tight junctions between adjoining principal cells. The intercellular spaces are contiguous with the perivascular spaces of the subepithelial blood capillaries. It is suggested that the absorptive and secretory functions occuring on the apical surface of cells may be related to the creation of an appropriate intraluminal milieu for the maturation of spermatozoa while the occurrence of these functions in the intercellular spaces may represent an exchange of substances between the principal cells and the subepithelial capillaries.     

Morphological and morphometric changes and epithelial apoptosis are induced in rat epididymis by long-term letrozole administration

The epididymis is an organ that plays a key role in sperm maturation. The aim of this study was to examine the association between the chronic treatment of mature male rats with letrozole and morphological evaluation and morphometric values of epididymis as well as changes in the number of apoptotic cells in epididymal epithelium. Adult rats were treated with letrozole for 6 months and the epididymis weight, morphology, morphometric values and the number of apoptotic cells in the epithelium were examined. Long-term aromatase inhibition resulted in presence of intraepithelial clear vacuoles, hyperplasia of clear cells and a hyperplastic alteration in the epithelium known as a cribriform change. Moreover, changes in diameters of the epididymal duct and the epididymal lumen and changes in the epididymal epithelium height were observed. The number of apoptotic epithelial cells was increased in letrozole-treated group. It can be indicated that chronic treatment with letrozole can affect morphology, morphometric values and apoptosis in the epididymis of adult male rats. Observed changes are similar to that observed in the aging processes and may also be important for patients treated with aromatase inhibitors.Key words: Estrogen, aromatase, letrozole, epididymis, morphology, apoptosis     

A morphologic study of the ductus of the epididymis of Sus domesticus

The head, body, and tail regions of the epididymal duct (or caput, corpus, and cauda epididymis) in two healthy and sexually mature Sus domesticus males were examined by light microscopy and by scanning or transmission electron microscopy. The epididymal duct is lined with a pseudostratified epithelium with stereocilia and covered by a muscular-connective tissue sheath that is thickest in the tail region. Diameter of the epididymal duct and height of epididymal epithelium are maximal in the head region. Length of the sterocilia and spermatic density are higher in the head and body regions. Somatic cells are abundant in the tail region. The epididymal epithelium is made up of five cell types: basal cells, principal cells, clear cells, narrow cells, and basophilic cells. Abundant secretory units are observed in the supranuclear cytoplasm of columnar principal cells. Each mature secretory unit is constituted by electron-dense secretion granules covered by more than eight layers of cisternae of reticulum between which the mitochondria are intercalated. In the apical cytoplasm the isolated secretion granules become larger and less electron dense. The apical surface is covered by numerous sterocilia. Basal cells are pyramidal and less high than principal cells. The clear cells, arranged between the principal cells, are characterized by the presence of abundant vesicular elements and electron-lucid secretion granules, and by an apocrine secretory process. The narrow cells are characterized by their highly vacuolized cytoplasm. Intermediate cell typologies can be found among basal, principal, clear, and narrow cells, which could be four developmental stages of the same cell type. The basophilic cells are spheroidal and are found at different levels between the epithelial cells and in the connective tissue underlying the epithelium. © 1993 Wiley-Liss, Inc.     

Light and electron microscopic observations on ciliated vacuoles and cysts in the oviductal and endocervical epithelia of the rabbit

Ciliated vacuoles and intraepithelial cysts have been observed in oviductal and endocervical epithelia of rabbits. In this study, rabbits under various hormonal conditions were studied by light and transmission electron microscopy and tissue culture in an attempt to determine their distribution and origin. Ciliated vacuoles most frequently lay in the basal cytoplasm, below or beside the nucleus, and very close to the basal lamina. A few were apically located. Their average diameter was 8.8 by 5.1 microns. Cilia and microvilli projected into the vacuolar lumen. These vacuoles were located intracellularly as evidenced first by the degeneration of both their cilia and microvilli and the moderately dense matrix that often filled the vacuolar lumen, as observed by electron microscopy. Secondly, phase microscopy of the living endocervical epithelium allowed us to observe the beating of the cilia within the vacuoles, not on the surface of such cells. Thirdly, ruthenium red stained the surface glycocalyx of ciliated and secretory cells, but not that of the cilia and microvilli within the vacuoles. The intraepithelial cysts were not observed in all tissue blocks. The largest numbers were found in ovariectomized animals treated for 3 and 5 days with estradiol. More were seen in the isthmus and cervix than in the fimbria and ampulla. The cysts were located most often within the epithelium along the sides of, and at the bases of, the mucosal folds. They were lined by flattened epithelium of various combinations of secretory and ciliated cells. An unusual cell type was associated with some of the cysts and ciliated vacuoles. Its cytoplasm contained aggregates of mitochondria and vesicles whose contents varied in density. Although the genesis of the ciliated vacuoles is not certain, our results indicate that they may arise from aberrant positioning of proliferating procentrioles or from a defect in targeting or transporting the centrioles to the apical plasma membrane to serve as basal bodies. Fusion of adjacent ciliated vacuoles with lumina lined by secretory cells having deep apical invaginations appeared to contribute to the formation of cysts.