结扎输出小管前后小鼠附睾表皮生长因子受体表达的变化

目的：观察结扎输出小管(EDL)前后小鼠附睾表皮生长因子受体(EGFR)的变化,探讨睾丸网液成分是否影响附睾EGFR的表达。方法：应用免疫组化和图像分析方法观察并比较EDL前、EDL后3d、7d、14d小鼠(n=7)附睾起始部和体部的结构和EGFR表达。结果：EDL后,小鼠附睾起始部和体部EGFR表达强度降低。起始部EGFR阳性面积自EDL后第3天明显减少,第7天较第3天有所增加,第14天恢复到正常水平。小鼠附睾体部EGFR阳性面积在结扎早期无明显变化,到EDL后第14天明显增加。EDL后第3天起,小鼠附睾起始部管壁和管腔面积显著减少。EDL后第14天附睾体部管壁和管腔面积减少。结论：睾丸网液的成分通过不同作用机制影响附睾起始部和体部的结构和EGFR的表达。     

Ultrastructural changes during acute acetaminophen-induced hepatotoxicity in the mouse: a time and dose study

This study was undertaken to evaluate the early ultrastructural changes during the development of acetaminophen hepatotoxicity. Doses at or near the threshold for hepatotoxicity were selected to permit comparison of early reversible effects to those which ultimately progressed to necrosis in the absence of early agonal effects or drug-induced mortality. Both 300- and 600-mg/kg doses resulted in similar declines in hepatic glutathione levels to 14 and 22% of control values, respectively, by 2 hours, with more rapid recovery after the low dose. Plasma sorbitol dehydrogenase activity was elevated after 600 mg/kg but not after 300 mg/kg. During the first 2 hours after acetaminophen there was cytomegaly with rapid progression to necrosis after 600 mg/kg but minimal progression after 300 mg/kg. Ultrastructurally, vesiculation, vacuolation and mitochondrial and plasma membrane degeneration culminated in scattered single cell death by 4 hours and widespread centrilobular necrosis by 8 hours after 600 mg/kg. The time course of lesion development was slower after 300 mg/kg with damage restricted to the first two to three rows of centrilobular cells and limited numbers of isolated necrotic cells by 8 hours. By 18 to 24 hours livers of mice given 300 mg/kg appeared normal. Results are consistent with the endoplasmic reticulum being the site of acetaminophen activation and initial attack. However, early ultrastructural changes in mitochondria and plasma membrane observed after the high dose were not prominent after the low dose. This suggests that early acetaminophen damage to these organelles may play a critical role in acetaminophen hepatotoxicity.     

Effect of DL-6-(N-alpha-pipecolinomethyl)-5-hydroxyindane maleate (PMHI) on the reproductive system of a wild rat, Bandicota bengalensis. II. Epididymis and accessory sex glands

The effect of PMHI on the epididymis and accessory sex glands (ventral prostate, seminal vesicle, and coagulating gland) was studied in a wild rodent, the bandicoot rat. Animals were given a single subcutaneous injection of PMHI (150 mg/kg body wt) and were killed 2, 10, or 30 days later. Treatment of PMHI resulted in severe alterations in the epididymis of the bandicoot rat with no apparent effect on accessory sex glands except for a transitory decrease in epithelial height of the seminal vesicle and in peripheral acini of the ventral prostate. Changes in the epididymis included a marked involution of the caput, Zone I in particular, formation of sperm granulomata, and the distension of the "clear" cells in the caudal portion of the duct. Sperms progressively disappeared from the lumen and by Day 30, the cauda epididymis became completely azoospermic. It appears that the epididymal lesions produced by this compound may play a contributory role to induce infertility in the bandicoot rat.     

Effect of cyproterone acetate on structure and function of rhesus monkey reproductive organs

A low dose of Cyproterone acetate (CPA; 1 mg/kg body weight/day for 70 days) was administered to adult male rhesus monkeys to assess its effects on testicular and epididymal structure and function in a nonhuman primate species. CPA caused extensive degenerative changes in morphology of seminiferous, efferent duct, and epididymal epithelia, including decrease in diameter of seminiferous and epididymal tubules and their lumen, height of epididymal epithelium, and an increase in intertubular connective tissue. The protein profile of spermatozoa showed alterations during their epididymal transit in control and CPA-treated monkeys. In CPA-treated animals, 19 polypeptides were acquired and nine were eliminated during epididymal transit in contrast to acquisition of 12 and loss of 14 polypeptides in control animals. Treatment with CPA also resulted in the appearance of 14 new polypeptides in epididymal cytosol and luminal fluid, probably of lysosomal origin. The protein pattern of caput and cauda epididymal tubule cytosol, maintained in organ culture and exposed to 100 μM CPA for 3 days, showed absence of eight polypeptides. These results indicate that even at the low dose used in this study, CPA has caused spermatogenic arrest, degenerative changes in the epididymal structure, and alterations in epididymal and sperm protein profile. Suppression of serum testosterone levels indicates the need for androgen supplementation if CPA is to be used for male contraception. © 1992 Wiley-Liss, Inc.     

Effect of cyproterone acetate on structure and function of rhesus monkey reproductive organs.

A low dose of Cyproterone acetate (CPA; 1 mg/kg body weight/day for 70 days) was administered to adult male rhesus monkeys to assess its effects on testicular and epididymal structure and function in a nonhuman primate species. CPA caused extensive degenerative changes in morphology of seminiferous, efferent duct, and epididymal epithelia, including decrease in diameter of seminiferous and epididymal tubules and their lumen, height of epididymal epithelium, and an increase in intertubular connective tissue. The protein profile of spermatozoa showed alterations during their epididymal transit in control and CPA-treated monkeys. In CPA-treated animals, 19 polypeptides were acquired and nine were eliminated during epididymal transit in contrast to acquisition of 12 and loss of 14 polypeptides in control animals. Treatment with CPA also resulted in the appearance of 14 new polypeptides in epididymal cytosol and luminal fluid, probably of lysosomal origin. The protein pattern of caput and cauda epididymal tubule cytosol, maintained in organ culture and exposed to 100 microM CPA for 3 days, showed absence of eight polypeptides. These results indicate that even at the low dose used in this study, CPA has caused spermatogenic arrest, degenerative changes in the epididymal structure, and alterations in epididymal and sperm protein profile. Suppression of serum testosterone levels indicates the need for androgen supplementation if CPA is to be used for male contraception.     

Microvasculature of the mouse epididymis, with special reference to fenestrated capillaries localized in the initial segment

The blood supply, microvasculature, and ultrastructure of the capillaries in the epididymis in adult mice were regionally examined. The epididymal duct of the initial segment is surrounded with a dense network of fenestrated capillaries running just under the epithelium. The other segments have loose networks of nonfenestrated capillaries running in the interductal connective tissue. The fenestration of capillaries in the initial segment was markedly reduced in frequency immediately after cutting the efferent duct. In adult mice which were subjected to cutting of the efferent duct neonatally, the dense capillary network did not develop, and fenestrated capillaries were absent in the initial segment. We interpret our results to indicate that the fenestrated capillaries in the initial segment provide for absorption of the testicular fluid and that their development is dependent upon the testicular fluid entering the epididymal duct.     

Epithelial cells of the epididymis show regional variations with respect to the secretion of endocytosis of immobilin as revealed by light and electron microscope immunocytochemistry.

The localization of immobilin, a glycoprotein known to be present and to immobilize spermatozoa in the lumen of the epididymis, was investigated using light and electron microscope immunocytochemistry. In the light microscope, a distinct immunoperoxidase reaction product was observed in the lumen over the brush border of the epithelial nonciliated cells of the efferent ducts, while only a faint reaction was seen over their supranuclear region. In the proximal area of the initial segment of the epididymis no immunoperoxidase staining was observed either over epithelial cells or in the lumen. In the middle area of the initial segment, several epithelial principal cells became intensely immunostained but the majority were unstained; a weak reaction appeared in the lumen. In the distal area of the initial segment, more principal cells became immunostained, and while some were intensely reactive, others were moderately or weakly stained or unreactive. In the intermediate zone and proximal caput epididymidis, the principal cells showed the maximal immunoreactivity with all principal cells being reactive; staining in the lumen also reached its maximal reactivity in these areas. Immunostaining of principal cells gradually decreased along the epididymal duct and disappeared in the cauda epididymidis, however, an intense reaction persisted in the lumen. In the distal area of the cauda epididymidis, clear cells were reactive. In the electron microscope, immunogold labeling of reactive principal cells of the middle and distal areas of the initial segment, intermediate zone, and caput epididymidis was detected over cisternae of endoplasmic reticulum, stacks of Golgi saccules, and spherical electron lucent (200-400 nm in diameter) vesicles. The latter were present on the trans face of the Golgi stack, in the vicinity of th Golgi apparatus, and close to the apical cell surface; they are considered as secretory vesicles involved in the secretion of immobilin. In the distal area of the cauda epididymidis, epithelial clear cells showed an intense immunogold labeling over their endocytic apparatus. Immunogold labeling in the lumen of the epididymis was found over a fine flocculent material dispersed between the sperm. This material was especially abundant in the cauda epididymidis and did not appear to be bound to the surface of the sperm. The present results suggest that principal cells of the epididymis are involved in the secretion of immobilin, but that a differential secretory pattern exists between epididymal segments with maximal secretory activity occurring in the intermediate zone and proximal caput epididymidis, while no secretion takes place in the cauda epididymidis. Excess immobilin appears to be endocytosed for degradation by clear cells of the cauda epididymidis.     

Epithelial cells of the epididymis show regional variations with respect to the secretion or endocytosis of immobilin as revealed by light and electron microscope immunocytochemistry

The localization of immobilin, a glycoprotein known to be present and to immobilize spermatozoa in the lumen of the epididymis, was investigated using light and electron microscope immunocytochemistry. In the light microscope, a distinct immunoperoxidase reaction product was observed in the lumen over the brush border of the epithelial nonciliated cells of the efferent ducts, while only a faint reaction was seen over their supranuclear region. In the proximal area of the initial segment of the epididymis no immunoperoxidase staining was observed either over epithelial cells or in the lumen. In the middle area of the initial segment, several epithelial principal cells became intensely immunostained but the majority were unstained; a weak reaction appeared in the lumen. In the distal area of the initial segment, more principal cells became immunostained, and while some were intensely reactive, others were moderately or weakly stained or unreactive. In the intermediate zone and proximal caput epididymidis, the principal cells showed the maximal immunoreactivity with all principal cells being reactive; staining in the lumen also reached its maximal reactivity in these areas. Immunostaining of principal cells gradually decreased along the epididymal duct and disappeared in the cauda epididymidis, however, an intense reaction persisted in the lumen. In the distal area of the cauda epididymidis, clear cells were reactive. In the electron microscope, immunogold labeling of reactive principal cells of the middle and distal areas of the initial segment, intermediate zone, and caput epididymidis was detected over cisternae of endoplasmic reticulum, stacks of Golgi saccules, and spherical electron lucent (200–400 nm in diameter) vesicles. The latter were present on the trans face of the Golgi stack, in the vicinity of the Golgi apparatus, and close to the apical cell surface; they are considered as secretory vesicles involved in the secretion of immobilin. In the distal area of the cauda epididymidis, epithelial clear cells showed an intense immunogold labeling over their endocytic apparatus. Immunogold labeling in the lumen of the epididymis was found over a fine flocculent material dispersed between the sperm. This material was especially abundant in the cauda epididymidis and did not appear to be bound to the surface of the sperm. The present results suggest that principal cells of the epididymis are involved in the secretion of immobilin, but that a differential secretory pattern exists between epididymal segments with maximal secretory activity occurring in the intermediate zone and proximal caput epididymidis, while no secretion takes place in the cauda epididymidis. Excess immobilin appears to be endocytosed for degradation by clear cells of the cauda epididymidis.     

Early degeneration of the epithelial cells in the initial segment of the epididymal duct in mice after efferent duct cutting

Mouse epididymides were examined by light and electron microscopy 6, 12, 24 h, 1.5, 2, 3, and 5 days after efferent duct cutting when the mice were 60 days of age. Six hours after operation, the principal cells in the initial segment of the epididymal duct began to degenerate following the disappearance of intraluminal spermatozoa. The degenerated cells increased rapidly and reached their greatest number 24 h, and then decreased to smaller numbers until 48 h. These degenerative changes were followed by the appearance of macrophages in the epithelium, which were first seen 12 h after operation, becoming very frequent at one and 1.5 days, and then decreasing to become rare at 3 and 5 days. The macrophages phagocytosed the degenerated principal cells. The degenerated principal cells were also ingested and digested by undegenerated principal cells and basal cells. The intraepithelial mitotic figures had almost disappeared at 24 h but were frequently observed at 2 days and more so at 3 days. They returned to normal numbers at 5 days. The volume of the initial segment was decreased to one third until the third day. The principal cells in this segment became similar in both light-microscopic appearance and ultrastructures to the cells in the next segment 5 days after efferent duct cutting. The changes were localized only in the initial segment.     

Response of epididymal duct to the temporary depletion of spermatozoa induced by testicular irradiation in mice

The mouse epididymal duct can be histologically divided into five segments (I-V), and the principal cells in segment II appear to secrete periodic acid-Schiff (PAS)-positive material into the lumen. In this study, male dd-mice received one, two, or four 800-R doses of radiation beginning at age 50 days. Mice receiving multiple doses were irradiated at 1-week intervals. After irradiation, marked depletion of spermatozoa, or aspermia, occurred in the epididymal duct for 2 to 16 weeks after a latency period of 3 to 4 weeks according to the times of irradiations. During oligospermia or aspermia, PAS-positive inclusions appeared in the principal cells in segment IV. The inclusions occupied a supranuclear position and appeared as round granules and globules measuring 2-15 micron in diameter, and increased in number, size, and staining intensity with time. They disappeared after reappearance of spermatozoa. The findings suggest that PAS-positive material may bind to spermatozoa and, if not bound, is reabsorbed by the principal cells in segment IV and deposited as intracellular inclusions, and the principal cells in segment IV are capable of digesting the accumulated PAS-positive material.     

Relationship of interstitial edema with L-cysteine-induced sperm granulomas in the pubertal rat epididymis.

Although the pathogenesis of sperm granulomas is complicated, the leakage of spermatozoa into extraluminal tissues is regarded as a crucial event. It has been previously shown that pubertal rats injected with L-cysteine develop interstitial edema followed by sperm granulomas in the epididymis. In this study we investigated the relationships between these two lesions in 6-week old rats given daily intraperitoneal injections of L-cysteine (1,000 mg/kg body weight) for 4 weeks. Rats were examined during weeks 0, 1, 2, 3 and 4 after the first injection. Interstitial edema (moderate or severe) and sperm granulomas were seen in the corpus and cauda epididymis of L-cysteine-treated rats in study weeks 2, 3, and 4. There was no marked alteration of basement membrane of the epididymal ducts in the edematous tissues as shown by immunohistochemistry with an antilaminin antibody. However, the extravasation of Evans blue dye given I hour before necropsy suggested that the severe interstitial edema was due to increased vascular permeability. In addition, a small number of neutrophils were seen in the edematous tissues, suggesting that they might play a role in the increased vascular permeability and leakage of epididymal fluid. Interestingly, slight interstitial edema was observed in the caput epididymis in both control and L-cysteine-treated rats in early study weeks 0, 1, and 2. It is speculated that this change was related to the leakage of epididymal fluid due to increased intraluminal pressure depending on rat epididymal maturation. Taken together, these findings suggest that the severe interstitial edema results from increased vascular permeability. This, along with increased intraluminal pressure, might be the trigger for duct rupture, the prerequisite for sperm granuloma formation associated with excessive doses of L-cysteine.     

Cytological response of the principal cells in the initial segment of the epididymal duct to efferent duct cutting in mice

The principal cells in the initial segment of the mouse epididymal duct were observed by light and electron microscopy over a period from 6 h to 4 weeks after efferent duct cutting. These were compared with the cells in Segment II (the segment next to the initial segment), in order to understand the functional differentiation of both segments. In the initial segment, a large number of the principal cells were degenerated and disappeared within 2 days after the operation. The remaining epithelial cells rapidly decreased in height as the degeneration proceeded and the principal cells were light- and electron-microscopically transformed into the cells similar to the principal cells in Segment II. The principal cells in Segment II showed no changes after efferent duct cutting. The findings suggest that the principal cells in the initial segment have a secretory potentiality of Segment II cells, which is normally latent but becomes manifest after the efferent duct interruption that removes the absorptive function of the testicular fluid.     

The influence of progestin and androgen on the fine structure of the male reproductive tract of the rat. II. Epididymis and sex accessory glands

Young adult male rats were administered medroxyprogesterone (Provera, Upjohn) alone and in combination with testosterone, as has been done to inhibit male fertility. The histology and fine structure of several segments of the epididymis, the ventral prostate, and the seminal vesicle were studied at intervals after treatment for up to 16 weeks. The epididymides of treated animals weighed less than those of control rats. Microscopic alterations in the epididymis were similar in rats treated with Provera alone and in those animals that received Provera and testosterone, but the changes varied with the segment of the epididymis. In the middle segment in the caput epididymidis, the normally abundant luminal sperm were absent but the epithelium retained its normal ultrastructural features. In the terminal segment in the cauda epididymidis, different changes were observed in the proximal and distal portions. In the proximal cauda epididymidis, the lumen was small, irregular in outline, and virtually devoid of sperm. The light cells of the epididymal epithelium in the proximal cauda contained extremely large numbers of dense bodies resembling lysosomes, which occupied most of the supranuclear and basal cytoplasm. In contrast, in the distal part of the cauda epididymidis, the epithelium had a normal appearance but the lumen was filled with debris, sperm, and spherical masses of cytoplasm that were apparently derived from germ cells. It is suggested that the clearing of the lumen of the proximal cauda epididymidis may reflect the greater activity of light cells of the epididymal epithelium in that region. Although alterations in spermatogenesis may be most important in the antifertility effect of progestin and androgen, these alterations in epididymal sperm and epithelium may also play a role. The weights of the prostate and seminal vesicles of rats treated with Provera (1 mg/100 g/day) were greatly reduced compared to those of control rats. Although there was considerable variation, in many specimens treated with Provera alone the epithelium of the prostate showed a change from a columnar to a cuboidal or squamous shape, and there was a reduction in the size and abundance of organelles involved in the formation of secretions. The microscopic structure of the seminal vesicle of rats treated with Provera was less severely affected than the prostate. Although the seminal vesicle epithelium of Provera-treated rats was generally not as tall as in control animals, the cells possessed parallel cisternae of rough endoplasmic reticulum, secretory vacuoles, and an active-appearing Golgi apparatus, suggesting that they continued to be able to form secretions in the presence of Provera. The weights of the sex accessory glands were maintained at control levels by the administration of testosterone, 100 μg/100 g/day, along with the Provera. A normal fine structure was present in the epithelium of both the prostate and seminal vesicle of rats administered this amount of testosterone in addition to Provera. Lower doses of testosterone (15 or 30 μg/100 g/day) were insufficient to maintain normal weight or ultrastructure of the sex accessory glands in the presence of Provera.     

Permeability of the diaphragmatic mesothelium: The ultrastructural basis for “stomata”

The ultrastructure of the hamster efferent ducts and epididymis was studied and the results were correlated with previously published data on the composition of luminal fluid obtained by micropuncture. Samples of the efferent ducts and parts of the epididymis designated initial segment, caput, corpus, proximal cauda, distal cauda, and “epididymal vas” were prepared. The efferent ducts contained principal cells characterized by a profusion of apical vesicles and numerous very large vacuoles that were distributed throughout the cytoplasm. Ciliated cells had few vesicles and vacuoles. Occasional cells contained many particles resembling glycogen. In the epididymis, the following trends were observed. The height of the epithelium and the size of the principal cells declined from initial segment to distal cauda. Apical vesicles and vacuoles with a light content were extremely numerous in principal cells of the initial segment and decreased progressively in the more distal regions. In the initial segment, basal and perinuclear rough endoplasmic reticulum was abundant and was distended with a material that resembled newly synthesized protein. Further distally in the epididymis cisternae of the rough endoplasmic reticulum were narrow and contained little intracisternal material. Light cells containing many vesicles, vacuoles, and lysosome-like structures were very prominent in the caudal segments. The epithelium of the epididymal vas had features intermediate between cauda epididymidis and ductus deferens. The cytoplasmic droplet in luminal sperm began to migrate caudally between the caput and corpus epididymidis and reached the posterior extremity of the middle piece in the distal cauda. Some degenerating sperm were observed in the lumen of the distal segments of the epididymis. The abundance of cytoplasmic vesicles and vacuoles in principal cells of the efferent ducts and initial segment of the epididymis correlated with the site of greatest fluid absorption as determined by micropuncture studies, suggesting that these structures are involved in absorption of fluid from the lumen. Between the caput and distal cauda epididymal segments, where absorption of sodium and potassium but not of fluid occurred, there were few vesicles and vacuoles in principal cells, but the “light” cells were large and numerous and contained many vacuoles. The principal cells of the initial segment were best equipped with rough endoplasmic reticulum to synthesize a protein.     

Sperm of Galeorhinus galeus (Elasmobranchii,Triakidae) Traverse an Excurrent Duct System Characterized by Pronounced Regionalization: A Scanning Electron and Light Microscopy Study

The transport and subsequent maturation of spermatozoa in the vertebrate excurrent duct require the creation of a series of biochemically defined luminal milieus along the length of the duct. Such specialization is accomplished, among others, by changes in the epididymal histoarchitecture. Here we show that the intratesticular and extratesticular genital ducts of mating Galeorhinus galeus exhibit pronounced regionalization both in terms of epithelial histology and lumen diameter size. Findings also reveal distinct differences in the manner in which the spermatozoa were found in each segment of the duct. Novel scanning electron microscopy evidence is presented showing that the wide lumen ductuli epididymides, which ultimately convey the spermatozoa to the proximal epididymis, show functional specialization as well. The wall of the former consisted of cuboidal ciliated and nonciliated cells whose spatial arrangement in the duct wall resulted in a luminal surface showing lengthy rows of cilia‐free areas, with each row bordered on both sides by a single row of cilia. The proximal epididymis comprised several subregions whose epithelial histology varied widely. The distal epididymis and ampulla of the epididymis possessed many fingerlike projections and transverse septa, respectively. As the main storage site for spermatozoa, the ampulla completed the bundling of spermatozoa into spermatozeugmata. These were circular sperm masses in which the heads of the spermatozoa were aligned side by side and embedded in a seminal matrix, while their tails extended outward. These findings of pronounced regionalization differ greatly from the rather uniform epididymal histology seen in some rays. Anat Rec, 298:1938–1949, 2015. © 2015 Wiley Periodicals, Inc.     

Changes in the distribution of filipin-sterol complexes in the boar sperm head plasma membrane during epididymal maturation and in the uterus.

The distribution of filipin-sterol complexes (FSCs) and intramembranous particles (IMPs) in the plasma membrane of the late spermatid of the boar and of the sperm obtained from the epididymides, ejaculates, and uterus 2 hours after mating was examined by a freeze-fracture replica technique. In the late spermatid, the FSC density was found to be very low. A majority of the FSCs in the acrosomal plasma membrane (APM) appeared as protuberances on the E face in the epididymal, ejaculate, and uterine sperm. The density of the FSCs in the principal segment (PS) of the APM was 291 +/- 44 FSC/microns2 (mean +/- standard deviation, S.D.), 322 +/- 41 FSC/microns2 and 355 +/- 31 FSC/microns2 in the caput, corpus, and cauda epididymidis, respectively. In comparison with the cauda epididymal sperm, the FSC density gradually decreased in the PS of the ejaculated (277 +/- 39 FSC/microns2) and uterine sperm (243 +/- 50 FSC/microns2). The reduction was especially remarkable in the equatorial segment (ES), where the density of FSCs in ejaculated and uterine sperm decreased to about half and less than half of that in the cauda epididymal sperm, respectively. Large (13 nm) and small (8 nm) IMPs were distributed evenly and densely in the P face of the APM in the late spermatid, epididymal, and ejaculated sperm. In the uterine sperm, IMP-free areas were observed in the P face of the plasma membrane, a feature thought to represent one of the capacitation changes of the boar sperm.     

The initial segment of the rat epididymis is able to uptake immature germ cells shed by testicular damage

The initial segment of the caput epididymidis, the most proximal part of the rat epididymis, has specific functional characteristics. In the present study, the behavior of the epididymal epithelium from this region was evaluated after the exposure to a massive number of immature germ cells in the luminal fluid. The experimental release of immature germ cells from the seminiferous tubules was performed by injecting anti-microtubule compounds into the rete testis and the lumen of seminiferous tubules. Twenty-four hours after nocodazole or colchicine administration, a massive phagocytosis of immature spermatogenic cells, recognized as acrosin-positive structures, was easily observed in the epithelium of the initial segment of the epididymis assessed by light and electron microscopy. Immature germ cells were engulfed by epithelial cells, where most of them were found as cell debris at different stages of degradation. No signs of inflammation were observed either in the lumen or in the interstitium. The phagocytosis of immature germ cells was restricted to the epithelium of the initial segment of the epididymis, suggesting a role for this segment as the first selective barrier for the exclusion of abnormal gametes along the male genital tract.     

Increased frequencies of diploid sperm detected by multicolour FISH after treatment of rats with carbendazim without micronucleus induction in peripheral blood erythrocytes

The purpose of the present study was to determine the effect of a single oral dose of carbendazim (CARB) on the frequencies of numerical chromosome aberrations in sperm and on micronuclei in peripheral blood erythrocytes of rats. Dual colour FISH on epididymal sperm of rats treated 31 days before sacrifice (0, 50, 150, 450 and 800 mg/kg body wt CARB in corn oil), corresponding to exposure during late pachytene, revealed a clear induction of diploid sperm. Induction of aneuploid sperm was not observed. Although the absolute frequencies of diploidy were low, ranging from 0.03% in the control group to 0.22% in the highest dose group, the observed dose-response relationship was highly significant. In sperm of rats killed 50 days after treatment with CARB (corresponding to exposure of spermatogonial stem cells) the effect was no longer apparent. In a second experiment, in addition to more dose groups in the low dose range, the peripheral blood micronucleus assay was incorporated. Results of triple colour FISH on epididymal sperm of rats treated with CARB (0-800 mg/kg body wt) again showed induction of diploid, but not of aneuploid sperm. Induction was less prominent than in the first experiment, but the dose-response relationship for diploidy was again significant. In blood samples drawn from the tail vein 48 h after treatment with CARB induction of micronuclei in peripheral blood erythrocytes was not observed, whereas the micronucleus frequency was significantly increased after a single i. p. dose of mitomycin C (3 mg/kg body wt). In conclusion, the present results show that CARB induces diploidy in sperm, without an accompanying induction of micronuclei in erythrocytes. This finding suggests that in rats the peripheral blood micronucleus assay is a less sensitive indicator for the genotoxic potential of CARB than the epididymal sperm aneuploidy/diploidy assay.     

Changes in distribution and staining reactivity of PAS-positive material in the mouse epididymal duct after efferent duct ligation

The distribution of spermatozoa and that as well as the staining reaction of PAS-positive material in the epididymal duct were histologically observed in 60 day-old mice and mice 12 h, 24 h, 2 days, and 7 days after efferent duct ligation at 60 days of age. We divided the mouse epididymal duct into five segments; Segments I, II, and III making up the head of the epididymis, Segment IV the body, and Segment V the tail. The cytoplasm of the principal cells in Segment II was PAS-positive. The lumen of the epididymal duct contained spermatozoa and PAS-positive material in the distal portion of Segment I and other segments distal to Segment I. The lumen in Segments IV and V was distended with abundant spermatozoa and PAS-positive material. After efferent duct ligation, spermatozoa disappeared from the lumen in Segments I, II, and III within 2 days, whereas they took 5 days to pass from Segment IV. As spermatozoa disappeared, the luminal material increased in intensity of the PAS-reaction in the distal portion of Segment I and initial portion of Segment II and Segment IV. Segment I became similar in appearance to Segment II 7 days after the ligation. The findings suggest that the PAS-positive material is produced in the distal portion of Segment I and Segment II and accumulates, in the absence of spermatozoa, at the production site and Segment IV, a storage site of spermatozoa; furthermore, Segment I has the capacity of exerting a Segment II-like function, which becomes distinct after blocking the entrance of the testicular fluid.