Biomedical subjects

R A Hess

Publications and source records attributed to R A Hess.

At least 19 recordsLinked to original sources

PubMed2002

Stage-specific effects of the fungicide carbendazim on Sertoli cell microtubules in rat testis.

The aim of the present study is to provide a morphological explanation of carbendazim (CBZ)-induced sloughing of germ cells that occurs in a stage-specific manner. Therefore, very early alterations in the seminiferous tubule epithelium were examined histologically in the rat testis after oral administration of CBZ (400mg/kg). Gaps between the elongated and round spermatids, the first indication of germ cell sloughing (pre-sloughing), were observed in stage late VI-early VII seminiferous tubules at 90-min post-treatment. Tubulin immunoreaction in the Sertoli cells was reduced in intensity in tubules with pre-sloughing. However, electron microscopy demonstrated that there were some intact microtubules in these cells. At 120 min, sloughing was seen in stage late VI-early VII and XIII-XIV. Tubulin immunoreaction in the Sertoli cells was greatly decreased in intensity in tubules where cell sloughing was observed. Electron microscopy showed that there were few microtubules in the body region of these cells. Stages II-V and mid-VII-VIII were exempt from the sloughing effect at 180 min. These changes in microtubules were not observed in Sertoli cells that did not exhibit sloughing characteristics, regardless of the post-treatment intervals. The present results suggest that stage specificity of sloughing is due to the stage-specific susceptibility of Sertoli cell microtubules to CBZ.

Administration, Oral↗

PubMed2002

Epididymal lithiasis in roosters and efferent ductule and testicular damage.

Epididymal stones have been reported in roosters in the USA and Japan. The cause of this dysfunction, which is associated with low fertility, is not known. The hypothesis of the present study is that a potential cause is the aggressive selection of birds over many centuries based upon female egg laying traits, without concern for potential effects on the male. If this hypothesis is correct, one potential consequence would be the presence of epididymal stones only in domesticated fowl and this observation would be worldwide in distribution. The present study investigated epididymal lithiasis in Brazilian crossbreed roosters and two other fowl strains, in addition to several domestic and wild bird species. The efferent ductules contained stones in 94.3% of the roosters, but stones were absent in all other domestic and wild birds. The stones were irregular in shape, size and colour and consisted mainly of calcium. In affected roosters, the efferent ductules showed epithelial cell vacuolization and sloughing and peritubular mononuclear cell infiltration, culminating with atrophy. Signs of epithelial re-canalization were seen in ductules occluded by abnormal content, such as stones. In the testis, decrease in mass, sloughing of epithelium, mononuclear cell infiltration and tubular atrophy occurred. No correlation was found between the occurrence of stones and a positive test for ELISA IBV (infectious bronchitis virus), or between the number of stones and calcium concentration in water and food, indicating that IBV infection and calcium in the diet were not related to stones formation. This study confirms and extends information about the epididymal lithiasis, which appears to be unique for roosters but to occur around the world. The severity of the lesion points to potentially severe economical impact in the poultry industry.

Animals↗

PubMed2001

Estrogen action and male fertility: roles of the sodium/hydrogen exchanger-3 and fluid reabsorption in reproductive tract function.

Estrogen receptor alpha (ER alpha) is essential for male fertility. Its activity is responsible for maintaining epithelial cytoarchitecture in efferent ductules and the reabsorption of fluid for concentrating sperm in the head of the epididymis. These discoveries and others have helped to establish estrogen's bisexual role in reproductive importance. Reported here is the molecular mechanism to explain estrogen's role in fluid reabsorption in the male reproductive tract. It is shown that estrogen regulates expression of the Na(+)/H(+) exchanger-3 (NHE3) and the rate of (22)Na(+) transport, sensitive to an NHE3 inhibitor. Immunohistochemical staining for NHE3, carbonic anhydrase II (CAII), and aquaporin-I (AQP1) was decreased in ER alpha knockout (alpha ERKO) efferent ductules. Targeted gene-deficient mice were compared with alpha ERKO, and the NHE3 knockout and CAII-deficient mice showed alpha ERKO-like fluid accumulation, but only the NHE3 knockout and alpha ERKO mice were infertile. Northern blot analysis showed decreases in mRNA for NHE3 in alpha ERKO and antiestrogen-treated mice. The changes in AQP1 and CAII in alpha ERKO seemed to be secondary because of the disruption of apical cytoarchitecture. Ductal epithelial ultrastructure was abnormal only in alpha ERKO mice. Thus, in the male, estrogen regulates one of the most important epithelial ion transporters and maintains epithelial morphological differentiation in efferent ductules of the male, independent of its regulation of Na(+) transport. Finally, these data raise the possibility of targeting ER alpha in developing a contraceptive for the male.

Absorption↗

PubMed2001

Human estrogen receptor beta-specific monoclonal antibodies: characterization and use in studies of estrogen receptor beta protein expression in reproductive tissues.

Investigation of the role of the second, more recently described estrogen receptor, denoted ERbeta, will be critical in understanding the molecular mechanisms underlying tissue-specific gene regulation by estrogens. Expression of ERbeta in a variety of tissues has been examined predominantly at the mRNA level, and there is little information regarding the cellular localization and size of the endogenous ERbeta protein, due, in part, to the limited availability of human ERbeta-specific antibodies. Thus, our aim was to generate specific antibodies to human ERbeta and use them to determine the tissue-specific distribution and size(s) of the ERbeta protein. To this end, we have cloned three different hybridoma cell lines that produce monoclonal antibodies specific for the hormone-binding domain of human ERbeta. The antibodies, made in mice against human ERbeta amino acids 256-505 (hormone binding domain lacking the F domain), are designated CFK-E12 (E12), CMK-A9 (A9) and CWK-F12 (F12) and were determined to be the IgG gamma1 isotype for E12, and IgG gamma2b for A9 and F12. All three monoclonal antibodies could be used to detect in vitro translated, baculovirus expressed, and cell transfected and expressed ERbeta protein by Western blot analyses, and all failed to detect ERalpha. A9 and F12 were able to immunoprecipitate efficiently the native form of ERbeta protein in the presence and absence of estradiol. Epitope mapping studies indicate that the E12 and F12 antibodies recognize overlapping peptide sequences in the N-terminal region of the hormone-binding domain, a region that is highly conserved among species. Immunocytochemical studies with these antibodies reveal nuclear-specific localization of the ERbeta protein in granulosa cells of the rat ovary. Nuclear ERbeta is also specifically localized in epithelial and some stromal cells of mouse and rat epididymis. Western blot analysis with protein extracts from ovarian granulosa cells of human, rat, mouse, and pig showed a ca. 52 kDa and an additional ca. 62-64 kDa band in these species. These results indicate the presence of two predominant molecular size forms of the ERbeta protein in ovarian granulosa cells and demonstrate the utility of these antibodies for detection of ERbeta in the human and in several other mammalian species.

Animals↗

PubMed2001

Oestrogen, its receptors and function in the male reproductive tract - a review.

Oestrogen is synthesized in the male reproductive system by at least three different cell types; Sertoli, Leydig and germ cells. Although testosterone is recognized as the primary sex steroid in man, oestrogen is produced in sizable quantities in the testis, as well as the brain and is found in extremely high concentrations in the semen of several species. The high concentration of oestrogen in rete testis fluid of the rodent is now thought to be derived from the conversion of testosterone to estradiol by P450 aromatase in germ cells of the testis and spermatozoa traversing the reproductive tract. This new major source of oestrogen would target oestrogen receptors in the male reproductive tract, in particular the efferent ductules, which contain the highest concentration of oestrogen receptor-alpha. This recent data raises new hypotheses regarding the role of oestrogen in the function of the male reproductive system. The oestrogen receptor-alpha knockout mouse was used to help define the function of oestrogen in the male. It was found that oestrogen receptor-alpha is essential for fluid reabsorption in the efferent ductules and in the absence of expression the male is infertile.

Animals↗

PubMed2001

Morphological analysis of endocytosis in efferent ductules of estrogen receptor-alpha knockout male mouse.

Lack of estrogen receptor (ER) results in fluid accumulation and dilation of the efferent ductules, suggesting that the role of estrogen and ER in the male reproductive tract is related to fluid reabsorption in the ductules. In the present study, endocytosis of the nonciliated cells of the efferent ductules was compared morphologically between wild type (WT) and estrogen receptor-alpha knockout (alpha ERKO) male mice. The epithelial cells lining the WT efferent ductules were tall columnar in shape, whereas those of the alpha ERKO were low columnar. Immunocytochemically, the nonciliated cells of both genotypes showed positive reactions of sulfated glycoprotein-2, but the reaction products were reduced in amount in the alpha ERKO. Electron microscopy revealed that the nonciliated cells of the WT had numerous organelles for endocytosis such as coated pits and vesicles, tubules, endosomes, multivesicular bodies and lysosomes in the apical cytoplasm. These organelles were less developed in the nonciliated cells of the alpha ERKO. Morphometric analysis indicated that there was a significant reduction in area of endocytotic apparatus in the nonciliated cells of the alpha ERKO compared with that of the WT. A tracer study using gold particles demonstrated that the nonciliated cells of both WT and alpha ERKO efferent ductules were capable of taking up luminal contents. These results suggest that reabsorption of the luminal contents via endocytosis takes place in the efferent ductules but is greatly reduced in amount in the absence of ER alpha.

Animals↗

PubMed2001

Estrogens and epididymal function.

Estrogen is synthesized in the male reproductive system and is found in high concentrations in rete testis and seminal fluids. This luminal estrogen targets estrogen receptors (ER) along the male reproductive tract, and in particular the efferent ductules, where ERalpha is abundant. However, both ERalpha and ERbeta are found in various regions of the male reproductive tract. The transgenic ER knockout mice (alphaERKO and betaERKO) have been used to help define the role of ER in the male. In the alphaERKO animal model, the efferent ductules are dramatically altered, forming an epithelium in which fluid reabsorption is inhibited and epithelial cells have greatly reduced numbers of lysosomes and organelles associated with endocytosis. The betaERKO male reproductive tract appears normal. Because these animals are transgenic and lack ER throughout development, we developed animal models using pure antiestrogen ICI 182,780 treatments in adult males. The data show that ERalpha participates in the regulation of the apical cytoplasm of non-ciliated cells of the efferent ductules, narrow cells of initial segment epididymis and clear cells in the remaining segments of the epididymis. There appears to be no effect on vas deferens. The inhibition of ERalpha function in the male leads to decreases in sperm concentrations and eventually to infertility. The current literature leaves the mechanisms of estrogen action in the male reproductive tract unsettled and raises the question of androgen's contribution to the regulation of fluid transport, especially in the efferent ductules.

Animals↗

PubMed2001

Infertility and testicular atrophy in the antiestrogen-treated adult male rat.

The estrogen receptor-alpha (ERalpha) knockout mouse (alphaERKO) lacks ERalpha throughout development; therefore, an adult model for the study of estrogen effects in male mice was recently developed using the antiestrogen ICI 182,780. However, differences between species have been noted during immunostaining for ERalpha in the male tract as well as in response to treatments with antiestrogens. Therefore, we developed the antiestrogen model in the adult male rat to test, in another species, the hypothesis that estrogen regulates fluid reabsorption in efferent ductules. Estrogen receptor in the rat was blocked using ICI 182,780 for 100-150 days. Male Sprague-Dawley rats were treated weekly with s.c. injections of ICI 182,780 (10 mg) or castor oil (as control). The effects of ICI included testicular atrophy and infertility, similar to terminal effects in the alphaERKO male. Additionally, ICI induced dilations of the rete testis and efferent ductules and a reduction in the height of the ductule epithelium, which are changes similar to those in both alphaERKO and ICI-treated mice. One difference between species was a large variation in effects on the rat efferent ductule epithelium, including a transient increase in the number of periodic acid-Schiff-positive, lysosomal-like granules. These data confirm that estrogen is required for normal function of the efferent ductules and is essential for long-term fertility in the male rodent.

Animals↗

PubMed2000

Pressure cycling technology: a novel approach to virus inactivation in plasma.

BACKGROUND: Hydrostatic-pressure virus inactivation is a novel approach to the inactivation of pathogens in plasma and blood-derived components, that retains the therapeutic properties of these products. STUDY DESIGN AND METHODS: A custom-built apparatus was used to pressurize human plasma samples spiked with lambda phage. Phage titer and plasma protein activities were monitored after pressure treatment. RESULTS: Pressure-mediated inactivation of lambda phage was found to be an effective means for virus inactivation, particularly when performed at near-zero (0 degrees C) temperatures, rather than at temperatures above 20 degrees C and below -40 degrees C. The efficiency of inactivation was improved by an increase in applied pressure and repeated cycling from atmospheric to high pressure. In contrast, activities of plasma proteins alkaline phosphatase and total amylase did not vary with temperature and remained within 29 percent and 6 percent, respectively, of starting values after the same pressure treatments. By combining cycling, near-zero temperatures, and high pressure, phage titers in serum were reduced approximately 6 log after 10 to 20 minutes of treatment. Activities of plasma proteins IgG, IgM, and factor X were at 104 percent, 89 percent, and 80 percent, respectively, of starting values after 20 minutes of the same temperature and pressure treatment. CONCLUSION: High-pressure procedures may be useful for the inactivation of viruses in blood and other protein-containing components.

Antibodies, Viral↗

PubMed2000

Identification of epididymal stones in diverse rooster populations.

The epididymal region of the male reproductive tract is essential for sperm maturation, and dysfunction of this region results in infertility. Adult roosters have been observed to develop epididymal stones and consequently have reduced fertility. Efferent ductule cysts were first observed in White Leghorn roosters ages 18 to 26 wk. By 26 wk of age, the cysts had become solid, irregularly shaped, yellow-green stones primarily containing calcium (48%). The number and size of stones (9 to 160 microm, largest diameter) increased with age in affected males. Incidence ranged from 0 to 94% within rooster flocks surveyed. Stones have also been observed in broiler breeder roosters. Histological analysis of Leghorn and broiler breeder reproductive tracts revealed chronic inflammation with abundant interstitial mononuclear cell infiltrates. The normal, highly folded structure of efferent ductules was replaced by a thin, eroded epithelial layer with few luminal sperm. Abnormal areas were found interspersed with normal areas of epithelium. Broiler breeder male fertility trials demonstrated that birds with stones compared with normal males had reduced fertility following both natural mating (24.8+/-10.5% vs. 66.1+/-7.2%) and artificial insemination (47.8+/-16% vs. 82.0+/-6%). At 62 wk of age, testis weight (14.2+/-1.4 g vs. 20.5+/-1.2 g), daily sperm production (8.1+/-1.3 x 10(8) vs. 12.3+/-0.8 x 10(8) sperm per testis per day), and circulating testosterone concentrations (0.9+/-0.3 vs. 2.6+/-0.4 ng/mL) were all significantly reduced in males with stones. In conclusion, we are reporting a new dysfunction of the rooster reproductive tract that affects diverse bird populations and decreases fertility.

Animals↗

PubMed2000

Postulated human sperm count decline may involve historic elimination of juvenile iodine deficiency: a new hypothesis with experimental evidence in the rat.

Human sperm count studies, historic dietary iodination, and an animal model where neonatal goitrogen administration causes unprecedented testis enlargement, together suggest an hypothesis relevant to the postulated fall in human sperm counts. We present the hypothesis with a supporting study extending the model to include iodine deficiency. In a one-generation rat reproduction study, dams were fed an iodine sufficient (control, 200 ppb I) or deficient (low iodine diet [LID], <20 ppb I) diet from prebreeding through weaning, when male offspring were divided into three groups: 1) controls from iodine sufficient dams, 2) neonatal LID (NLID) from the LID dams, fed control diet postweaning, and 3) chronic LID (CLID) from LID dams, fed a moderate LID (40 ppb I) postweaning. F1 males were euthanized on postnatal day (PND) 133+/-1. Each of the three diet groups comprised two subgroups in which testicular parameters were evaluated: 1) daily sperm production (DSP), sperm motility, morphology, and histopathology, and 2) Sertoli cell and round spermatid morphometry. In the first subgroup, NLID and CLID testes weights were 8.5% and 14.0% heavier than their unusually heavy controls (3.921 g; historical control mean approximately 3.5 g), with proportional DSP increases. Sperm motility, morphology, and testis histopathology were unaffected. In the morphometry subgroup, respective increases in NLID and CLID rats included testes weights (+28.6% and +20.3%), Sertoli cells (+24.8% and +23.9%), and round spermatids (+20.4% and +15.8%). The results indicate that neonatal iodine deficiency can significantly increase spermatogenic function in rats, and support our hypothesis concerning human sperm counts.

Animals↗

PubMed2000

Estrogen receptor alpha has a functional role in the mouse rete testis and efferent ductules.

Previous studies of the estrogen receptor-alpha knockout (alpha ERKO) in the male mouse demonstrate that the rete testis and efferent ductules are targets of estrogen. Because the alpha ERKO mouse lacks a functional estrogen receptor alpha (ER alpha) throughout development, it was not known whether the morphological and physiological abnormalities observed in the alpha ERKO male were due to developmental defects or to dysfunctions concurrent with the lack of ER alpha in the tissue. This study was designed to determine if treatment of normal wild-type (WT) mice with the pure antiestrogen, ICI 182,780, (ICI) could reproduce the morphological characteristics seen in alpha ERKO mice. Thirty-day-old male mice were treated for 35 days with either castor oil or ICI. Age-equivalent alpha ERKO mice were used for comparison. Light microscopic examinations of the reproductive tracts revealed dramatic changes in the efferent ductules of treated mice: a 1.7-fold increase in luminal diameter, a 56% reduction in epithelial cell height, a 60% reduction in brush boarder height of nonciliated cells, and an apparent reduction of the number of observable lysosomes and endocytotic vesicles. Testes of ICI-treated mice showed swollen rete testes area (6.5 times larger than control) and a 65% reduction in rete testis epithelium height. However, there were no significant changes in body and testis weights. These results indicate that ER blockage with ICI in WT mice results in morphological changes of the efferent ductules resembling those seen in alpha ERKO siblings of the same age. Based on this study, we conclude that ER alpha has a functional role in the mouse reproductive tract and the aberrant morphology observed in the efferent ductules of the alpha ERKO mouse is likely the result of a concurrent response to the lack of functional ER alpha, and not solely due to the lack of ER alpha during early developmental times.

Animals↗

PubMed2000

The differential fate of mesonephric tubular-derived efferent ductules in estrogen receptor-alpha knockout versus wild-type female mice.

We investigated mesonephric tubular-derived efferent ductules in female wild-type (WT) and estrogen receptor-alpha knockout (ERalphaKO) mice from late fetal to adult life. On gestational day 17, efferent ductules in both fetal WT and ERalphaKO females were well developed and morphologically similar, although one third the size of the male counterpart. Unexpectedly, efferent ductules with a ciliated epithelium were still present on postnatal day 10 in WT and ERalphaKO females. By day 23, however, marked phenotypic differences occurred in efferent ductules of WT and ERbetaKO vs. ERalphaKO female mice. In the latter, efferent ductules became hypertrophied and dilated, whereas only small tubules remained in WT and ERbetaKO adult mice. The serum testosterone concentrations were similar in 21- to 25-day-old ERalphaKO, heterozygous, and WT female mice, suggesting that increased testosterone was not inducing enlargement of efferent ductules in ERalphaKO females. In conclusion, remnants of efferent ductules persisted in normal adult female mice, although these structures were greatly reduced in size compared with efferent ductules in ERalphaKO female mice. The underlying mechanism inducing hypertrophy and dilation of efferent ductules in ERalphaKO females is not clear, but secretory and/or reabsorptive function of female efferent ductules may involve ERalpha.

Animals↗

PubMed2000

Histopathology of the male reproductive system induced by the fungicide benomyl.

Benomyl is an effective fungicide that has been in use for many years. This chemical and its primary metabolite, carbendazim, are microtubule poisons that are relatively nontoxic to all mammalian organs, except for the male reproductive system. Its primary effects, at moderate to low dosages, are on the testis, where it causes sloughing of germ cells in a stage-dependent manner. Sloughing is caused by the effects of the chemical on microtubules and intermediate filaments of the Sertoli cell. These effects spread to dividing germ cells and also lead to abnormal development of the head of elongating spermatids. At higher dosages, it causes occlusion of the efferent ducts, blocking passage of sperm from the rete testis to epididymis. The mechanism of occlusion appears to be related to fluid reabsorption, sperm stasis, followed by leukocyte chemotaxis, sperm granulomas, fibrosis and often the formation of abnormal microcanals. The occlusion results in a rapid swelling of the testis and ultimately seminiferous tubular atrophy and infertility. In conclusion, studies that reveal long term testicular atrophy following chronic or subchronic exposure to a toxicant should be re-examined for histopathological lesions in the efferent ductules and head of the epididymis. Lesions in the male track that cause blockage may induce permanent testicular damage and a decrease in sperm production.

Animals↗

PubMed2000

Oestrogen in fluid transport in efferent ducts of the male reproductive tract.

This review focuses on the importance of oestrogen and oestrogen receptors in the male reproductive system, with a special interest in the newly discovered role of oestrogen in the regulation of fluid reabsorption in the efferent ductules of the testis. Early work on oestrogen synthesis indicated that Leydig and Sertoli cells were the only important cells in the production of this steroid in the adult testis. However, more recent work has shown that germ cells and spermatozoa also contain aromatase and produce oestrogen. The observation that germ cells synthesize oestrogen contributed to a new hypothesis that oestrogen in the lumen of the male reproductive tract targets the epithelial lining of efferent ductules and the epididymis. The location of nuclear oestrogen receptors in the male reproductive tract has also been investigated and it has been found that oestrogen receptor alpha is more abundant in the efferent ductules of the testis than in any other tissue of the male or female. In all species examined to date, oestrogen receptor alpha has been found to be abundant in the efferent ductules. The structure and function of the efferent ductules are taken into account as these tubules are responsible for the reabsorption of almost 90% of the luminal rete testis fluid. Thus, it was logical to hypothesize that oestrogen receptors play a role in the regulation of fluid reabsorption in efferent ductules. The oestrogen receptor alpha knockout mouse was used to help define this role of the receptor in males. In this animal model, the efferent ductules are altered markedly from a reabsorptive epithelium to a squamous epithelium devoid of lysosomes and endocytotic organelles. Although the separate roles for oestrogens and androgens in the regulation of fluid reabsorption are controversial and remain to be resolved, it is now established that loss of oestrogen receptor function in males interferes with the resorptive function of efferent ductules, a function that is essential for fertility. Future studies will focus on the biochemical and physiological mechanisms involved in the regulation of water and ion movement by oestrogen in the male reproductive tract.

Animals↗

PubMed1999

A bioseparation apparatus with high-pressure fluid injection and fluid sampling.

A novel apparatus in which fluids may be injected and sampled at high pressure is described. Bioseparation applications of the apparatus were demonstrated in three model systems: (1) lambdaDNA was eluted under pressure from an anion exchange column into a low-salt (0.25 M) buffer, thereby eliminating conventional time-consuming desalting procedures required for downstream analysis of the DNA; (2) RNA was separated under pressure from a RNA/DNA mixture, thereby enabling rapid differential preparation of nucleic acids; and (3) an antibody was purified from a protein mixture by affinity capture at one pressure and dissociation from the antigen binding partner at a second pressure, thereby enabling the immunoreactivities of both antibody and antigen to be preserved during the separation process.

Animals↗

PubMed1998

Testicular toxicity of molinate in the rat: metabolic activation via sulfoxidation.

Molinate is a thiocarbamate herbicide widely used in rice culture. Studies conducted for regulatory purposes have indicated that molinate exposure causes male reproductive damage in rats. The present study describes the testicular lesion after administration of single doses of molinate. The hypothesis that a metabolite of molinate is responsible for testicular toxicity was also investigated. Testicular damage was evaluated histopathologically in Sprague-Dawley rats 48 h and 1, 2, and 3 weeks after administration of molinate (100-400 mg/kg i.p.). No testicular damage was seen at any time point at the 100 mg/kg dose level. Damage was first seen 1 week after 200 mg/kg and 48 h after 400 mg/kg. The lesion was characterized by Sertoli cell vacuolation, failed spermiation, and phagocytosis of spermatids particularly evident at Stages X and XI. With increasing time, damage progressed until disorganization of the seminiferous epithelium was extensive, multinucleated giant cells were numerous, and neither spermatozoa nor late step spermatids were present. At 3 weeks after administration of the two higher-dose levels, germ cells in the seminiferous tubules were almost completely absent. Administration of the sulfoxide metabolite of molinate (200 mg/kg i.p.) caused testicular damage similar in severity to that seen at the 400 mg/kg dose level for the parent compound, indicating that it was more potent as a testicular toxicant. In vitro metabolism studies using liver and testis microsomes found that the major metabolite in both preparations was molinate sulfoxide. Testis microsomes produced only slightly less sulfoxide when compared with liver microsomes. Molinate was also metabolized via ring hydroxylation to form small amounts of hydroxymolinate. The amount of hydroxymolinate was substantially less in testis microsomes. Overall, these data indicate that sulfoxidation of molinate plays a role in molinat-induced testicular toxicity. Moreover, molinate is metabolized readily by both liver and testis microsomal enzymes, suggesting that the molinate toxic metabolite could be formed in the testis in close proximity to its site of action.

Animals↗

PubMed1998

Carbendazim-induced abnormal development of the acrosome during early phases of spermiogenesis in the rat testis.

Effects of a single, high dose of orally administered carbendazim (100 mg/kg) on acrosome formation in the early phases of spermiogenesis were examined by electron microscopy and immunocytochemistry up to day 7.5 post-treatment. No obvious abnormality of acrosome development was noted in the Golgi phase spermatids on day 1.5 post-treatment. On day 3, step 1 spermatids were seen in stage III seminiferous tubules. In stage V tubules at this post-treatment interval, direct connections between the trans-side saccules of the Golgi stacks and the outer acrosomic membranes were observed in step 5 spermatids. Similar direct connections between these two organelles were also observed in the advanced round spermatids in later stages at days 4.5 and 7.5. On day 4.5, step 1 and 3 spermatids were seen in stage V tubules. On day 7.5, round spermatids with various abnormalities of acrosome development were observed in stage VII tubules, in addition to the discontinuous and granular acrosomes reported previously. These features were not observed in testes of control animals. In the immunocytochemical analysis using an antibody mMN7 that recognizes a protein delivered from the Golgi apparatus to the acrosome, spermatids exposed to carbendazim showed various abnormal immunostaining patterns in the acrosomes. On the other hand, strong immunoreactivity was observed in the Golgi saccules connecting to the acrosomes. These results suggest that in testis treated with carbendazim acrosome development is impaired during the early phases of spermiogenesis, and material supply from the Golgi apparatus to the acrosome is perturbed, which is a possible cause of the abnormal development.

Acrosome↗