Adult Rat Epididymis Research Articles

Effect of bisphenol A on the cauda epididymis of adult male albino rats and the possible protective role of quercetin

BackgroundBisphenol A is a compound released into the environment. It affects male reproductive organs. Quercetin is an antioxidant substance that attenuates various disorders induced by environmental contaminants.Aim of the studyTo study the effect of bisphenol A on histological structure and immun

Spermatic Granuloma and Inflammatory Reactions in Epididymis of Adult Rats following Testosterone Depletion

Depletion of testosterone (T), vasectomy or chemical insults are known to induce spermatic granuloma (SG) in epididymis, however, the exact mechanisms are unknown. We treated adult male rats with a Leydig cell specific toxicant ethylene dimethane sulfonate (EDS) to deplete T, causing SG formation in epididymis. Histological evaluation revealed the presence of testicular germ cells (TGC) in the caput of epididymis which were apoptotic. An increased proportion of tubular epithelial cells in caput were also apoptotic. Immunofluorescent staining showed extensive infiltration of monocytes/macrophages around the periphery of the shrunken tubules and SG. CD4+ and CD8+ lymphocytes were also detected inside the tubules and SG. In confirmation, quantitative real time PCR for mRNA of macrophage marker CD68, and lymphocyte markers CD4 and CD8 were increased in EDS treated epididymis compared to controls (19 fold, 3.5 fold and 7.5 fold respectively). Aquaporin 9 mRNA increased 11 fold in EDS treated epididymis which may be indicative of restricted testicular fluid flow into epididymis. These pathological conditions were reversed after T replacement in EDS treated rats. Thus, our data indicates that influx and accumulation of apoptotic TGCs in the epididymis due to the disintegration of the blood‐testis barrier and disruption of testicular fluid flow into epididymis may play a role in SG formation.

Characterization of pannexin1 and pannexin3 and their regulation by androgens in the male reproductive tract of the adult rat

Pannexins (Panxs) are channel-forming proteins that have homology to the invertebrate gap junction proteins, the innexins. These proteins form membrane channels implicated in ATP release. To evaluate the role of Panxs in the male reproductive tract, we investigated the distribution and regulation of Panx1 and 3 in the testis, efferent ducts (ED), and epididymis of adult rats. In the testis, Panx1 localized to the basal compartment of the seminiferous epithelium, while Panx3 was expressed in Leydig cells. In the ED, both Panxs were expressed in the apical region of ciliated cells. In the epididymis, Panx1 was detected at the base of the epithelium, at times encompassing basal cells, while Panx3 was restricted to the apical plasma membrane of principal cells. Panx3 immunoreactions were high throughout the entire epididymis while Panx1 was high in all regions except the initial segment. Multiple transcripts for Panx1 were identified, and sequence analysis indicated that alternative splicing might account for them. Orchidectomy resulted in the expression of multiple immunoreactive Panx1 bands, and these appeared to be androgen-repressed throughout the epididymis. Panx3 levels in all epididymal regions were also androgen-repressed. Deglycosylation experiments indicated that some Panx1 species were due to glycosylation, but this did not account for all Panx1 immunoreactive species. In summary, Panxs expressed in the epididymis and regulated by both alternative splicing events and androgens. These proteins may play a role in ATP secretion into the epididymal lumen and basal extracellular spaces for functions involving sperm transport and maturation.

Regulation and Characterization of the ATP-Binding Cassette Transporter-B1 in the Epididymis and Epididymal Spermatozoa of the Rat

It has been reported that following administration, alkylphenols, such as octylphenol, reach the testis and epididymis but fail to accumulate in these tissues, suggesting the rapid expulsion of these chemicals by transporters. Specialized transporters that function to restrict compounds that enter target cells have been identified. ABCB1 is a member of the ATP-binding cassette family of proteins capable of transporting a broad range of drugs and xenobiotics out of tissues. The objective of this study was to characterize the expression profile and functional role of ABCB1a and ABCB1b along the different regions (initial segment, caput, corpus [CS], and cauda [CA]) of the adult rat epididymis. ABCB1a and ABCB1b transcripts were detected in all four regions of the epididymis. Immunolocalization revealed minimal ABCB1 staining in epithelial cells or spermatozoa of proximal regions of the epididymis; however, this progressively increased in the CS and CA epididymis. This expression gradient was confirmed by Western blot, suggesting that spermatozoa acquire ABCB1 during epididymal maturation. Multidrug resistance (MDR) assays revealed that rat epididymal cells and epididymal spermatozoa display an MDR phenotype that can be inhibited under control conditions. To assess whether or not the system was inducible by alkylphenols, cells from an immortalized epididymal cell line (RCE) were exposed to different concentrations of nonylphenol. Results revealed a significant induction of both ABCB1a and ABCB1b messenger RNA and ABCB1 protein in RCE cells. Our findings demonstrate a role for ABCB1 in protecting both epididymal principal cells and spermatozoa from xenobiotics.

Di-n-butyl phthalate (DBP) exposure induces oxidative stress in epididymis of adult rats

Di-n-butyl phthalate (DBP) is a ubiquitous environmental pollutant, extensively used as a plasticizer in many products including plastics, cosmetics and medical devices. Previous studies have shown that DBP has potential testicular toxicity. Epididymis is known to play an important role in the maturation and storage of sperm. However, the effect and mechanism of action of DBP on epididymis is unclear. The present study was designed to investigate the effect of DBP on structure and function of epididymis in adult male rats by histological and biochemical study. Oxidative stress was also assessed in rat epididymis as an underlying mechanism. Forty SD adult rats were randomly allotted to four groups, and DBP was administered to each group by oral gavage at doses of 0 (control), 100, 250 and 500 mg/kg/day for 2 consecutive weeks. The results indicated that the epididymal toxicity of DBP is dose-dependent. Epididymal weight, activities of epididymal alpha-glucosidase and glutathione peroxidase (GSH-Px) was significantly decreased in rats of 500 mg/kg DBP exposure group compared to the control. The activity of superoxide dismutase (SOD) was significantly decreased while the level of malondialdehyde (MDA) was significantly increased in the epididymal tissue of the 250 and 500 mg/kg DBP exposure groups compared with the control group. Moreover, microscopy with hematoxylin and eosin (HE) staining showed that atrophy of epididymal tubules, the interstitial vascular was hyperemia and the lumina were oligozoospermic in rats of 500 mg/kg DBP exposure group. In conclusion, DBP exposure alters the epididymal structure and function by inducing oxidative stress in epididymis of adult rats.

Effect of formaldehyde exposure on structure and function of epididymis in adult rats: a histological and biochemical study

Formaldehyde (FA), a ubiquitous environmental pollutant, is extensively used in hospitals, laboratories, and industrial settings. Previous studies showed that FA exerts adverse effects on testicular function and as epididymis is known to play an important role in the maturation and storage of sperm, the effects of FA were examined on epididymis. In particular, this study was designed to investigate the influence of FA on structure and function of epididymis in adult male rats using histological and biochemical methods. Sprague-Dawley adult rats were randomly allotted to three groups and exposed to FA at a 0 (control), 0.5, or 10 mg m−3 by inhalation for 28 days. The results indicated that epididymal toxicity of FA was concentration dependent. Epdididymal structure and function in rats of 0.5 mg m−3 FA exposure group showed no apparent difference from control. However, epididymal weight, sperm count and motility, the activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were significantly decreased, whereas the levels of malondialdehyde (MDA) was significantly increased in epididymis of rats exposed to 10 mg m−3 FA. Moreover, microscopy with hematoxylin and eosin (H&E) staining showed atrophy of epididymal tubules, disintegration of epididymal epithelium, disorganization, and even vacuolar denaturalization of epididymal epithelial cells. There was hyperemia in interstitial vasculature and lumina were oligozoospermic in rats of 10 mg m−3 FA exposure group. In conclusion, FA exposure alters the epididymal structure and function by inducing oxidative stress in epididymis of adult rats.

Mechanism underlying transient gestational-onset hypothyroidism–induced impairment of posttesticular sperm maturation in adult rats

To understand the mechanism underlying gestational-onset hypothyroidism-induced male infertility. Controlled laboratory study. Research laboratory in a university department of endocrinology. Wistar rat. Pregnant rats were exposed to methimazole from embryonic days 9 to 14, 18, and 21, covering specific fetal periods of differentiation and development of male reproductive tract organs. Fertility of male rats was assessed by testing sperm count, forward motility, and in vivo fertilizing ability. Secretory activity of the epididymis was evaluated by quantifying sialic acid, carnitine, and glycerylphosphorylcholine. Bioavailability of androgens was assessed by quantifying testosterone in serum and testicular interstitial fluid and epididymal 5alpha-reductase activity/mRNA expression. Androgen receptor (AR) status in the epididymis was tested by detecting the expression levels of its mRNA and protein, as well as ligand binding activity. Data were analyzed statistically by one-way analysis of variance. Gestational exposure to methimazole decreased sperm forward motility, in vivo fertilizing ability, bioavailability of androgens, AR status, and secretory activity of the epididymis in adult rats. Transient gestational-onset hypothyroidism affects male fertility by impairing posttesticular sperm maturation process in the epididymis, owing to subnormal androgen(s) bioavailability, AR expression, and AR functional activity.

Mal-Development of the Penis and Loss of Fertility in Male Rats Treated Neonatally with Female Contraceptive 17α-Ethinyl Estradiol: A Dose-Response Study and a Comparative Study with a Known Estrogenic Teratogen Diethylstilbestrol

The objectives of this study were to find a minimal dose of 17alpha-ethinyl estradiol (EE) that is detrimental to the developing penis and fertility and to compare estrogenic effects between EE and diethylstilbestrol (DES). Neonatal rats received EE at 10 ng (1 microg/kg), 100 ng, 1 microg, or 10 microg per pup on alternate days from postnatal days 1 to 11 (dose-response study) or received EE or DES at 100 ng per pup daily from postnatal days 1 to 6 (comparative study). Effects of EE were dose dependent, with > or = 100-ng dose inducing significant (p < 0.05) reductions in penile length, weight, and diameter. Additionally, the penis was malformed, characterized by underdeveloped os penis and accumulation of fat cells. Fertility was 0% in the > or = 1-microg groups, in contrast to 60% in the 100-ng group and 100% in the 10-ng and control groups. Animals treated with > or = 10 ng had significant reductions in the weight of bulbospongious muscle, testis, seminal vesicle, epididymal fat pad, and in epididymal sperm numbers. A comparison of EE and DES effects showed similar reductions in penile weight and length and the weight of bulbospongiosus muscle, testis, seminal vesicle, epididymis, and epididymal fat pad in both adolescent and adult rats. While 5/6 control males sired, only 1/6 in the EE group and 0/6 in the DES group sired. Hence, neonatal exposure to EE at 10 ng (environmentally relevant dose) adversely affects male reproductive organs. A dose ten times higher than this leads to permanently mal-developed penis and infertility. Furthermore, EE and DES exposures show similar level of toxicity to male reproductive organs.

Effect of continuous local microdose norethisterone enanthate on the epididymis of adult rat.

Unilateral implantation of a small silastic capsule containing crystalline Norethisterone Enanthate (NE, average observed rate of release, 17-22 micrograms/24 h) into the epididymal fat-pad of adult rats induced drastic impairment of epididymal functional anatomy in the adjacent epididymis six weeks later without affecting the contralateral epididymis. Tubular elements in the ipsilateral epididymis were highly shrunken with their luminal epithelial height greatly reduced and the lumen devoid of spermatozoa as compared with the normal epididymis (full of spermatozoa) on the sham operated contralateral side.

Changes in the Epididymis of Adult Rats Following Experimentally induced Cryptorchidism

Zusammenfassung Veränderungen der Epididymis bei erwachsenen Ratten nach experimentell hervorgerufenem Kryptorchismus In der vorliegenden Studie werden biochemische und histologische Untersuchungen' am Nebenhoden der erwachsenen Ratte vorgenommen, nachdem experimentell ein Kryptorchismus angelegt war. Der Gehalt an Sialinsäure im Kopf- und Schwanz-Teìl des Nebenhodens fällt am 14. Tag nach dem operativen Eingriff ab und erreicht dann am 21. und 30. Tage ein etwa gleichhohes Niveau, das etwas unter den Werten des 14. Tages liegt. Demgegenüber liegt die histologisch faßbare Regression des Nebenhodens mit ihrem Maximum bereits am 7. postoperativen Tage. Der Gehalt an DNA fällt sowohl im Kopf- als auch im Schwanz-Teil des Nebenhodens bereits innerhalb von 7 Tagen ab und erreicht die niedrigsten Werte zwisehen dem 21. und 30. Tage postoperativ. Der Einbau von 3H-Phenylalanin in die Proteine des Kopf- und Schwanz-Teiles steigt zu einem Maximum am 7. postoperativen Tage an und fällt allmählich zwisehen dem 14. und 30. Tage ab. Demgegenüber zeigt die ventrale Prostate zu keiner Zeit dieser Intervallstudie einen ansteigenden Umschwung der Proteinprekursoren. Die Resultate sind statistisch signifikant. Es wird diskutiert, inwieweit diese Befunde in Beziehung stehen zu den Androgen-Schwellen-Erfordernissen des Nebenhodens und seiner Involution als Folge der Veränderungen bei den zirkulierenden Androgenen. Resumen Cambios en el epididimo de rata adulta con criptorquidia producida experimentalmente Estudios bioquimicos recientes indican que la elevada temperatura abdominal induce un defecto en la biosintesis esteroidea en el testículo criptorquídico. El epididimo, por otro lado, es un tejido andrögeno sensible. En este trabajo se estudian los efectos de la criptorquidia sobre el epidimo. Se utilizaron ratas macho de 3 meses, de raza Holtzman, a las que se les trasladaron los testes a la cavidad abdominal. Se autopsiaron 7, 14, 21 y 30 dias después de la inductión de la criptorquidia. La cabeza y cola del epididimo de un lado se utilizaron para determinatión del ac. siálico. El otro lado para estudio histopatológico. Se tomó frotis de la cola del epididimo para estudiar la presencia de espermatozoides y el patrón de motilidad. En la cabeza del epididimo se observaron durante la primera semana la presencia en la luz de grandes masas de material eosinófilo y unos pocos espermatozoides con PAS positividad disminuída. En la cola del epididimo los cambios histologicos más notables fueron disminución de la luz tubular, aumento en la altura de las célutas epiteliales y formatión de vacuolas. La luz no contenia espermatozoides el dia 21. La concentratión de acido siálico disminuyó significativamente en la cabeza y cola del epididimo desde el dia 14 de la interventión. El efecto nocivo sobre la actividad secretora del epididimo observada en este estudio puede ser debida a los siguientes factores: a) ausencia de espermatozoides en el epididimo; b) disminución de la testosterona circulante; c) cambio en el tipo de andrógeno sintetizado; y d) efecto directo de la temperatura abdominal. Por otro lado hay que destacar que no se observó disminución del acido cítrico en la próstata ventral de estos mismos animales, lo que apoya la hipótesis de que la próstata ventral de rata requiere mucho menos andrógenos que el epididimo para mentener su actividad funcional. El contenido de DNA en la cabeza y cola del epididimo disminuye a los 7 dias y alcanza su nivel más bajo a los 21–30 dias, mientras que la incorporatión — de fenilalonina H3 en las proteinas de la cabeza y cola del epididimo, aumenta alcanzando un máximo a los 7 dias y declina gradualmente desde el dia 14 al 30.

Distribution of lectin binding in rat testis and epididymis.

Seven lectins (PNA, RCA I, SBA, Con A, WGA, UEA I, DBA) conjugated with rhodamine were employed to analyse the staining pattern of glycoproteins with varying sugar residues in the testis and epididymis of adult Wistar rats. Some lectins (UEA I, SBA, DBA) gave rather specific staining of the mature acrosome, while others (PNA, RCA I) showed affinity for the early stages of acrosome formation or had a wide affinity for germinal and non-germinal cells and structures (Con A, WGA). In the epididymis the sperm mass had a homogeneous staining reaction with some lectins (PNA, RCA I, Con A, WGA, DBA) which also showed a rather strong reaction on the epithelial surface. It was concluded that this reaction is at least partially due to the secretory products synthetized by principal, apical, narrow and light cells of the epididymal epithelium. Some differences in the staining pattern of these cells were recorded indicating specialization of the cells for the production of distinct glycoproteins. The staining pattern of the interstitial and intertubular compartment of the testis and epididymis was also recorded.

Microvillar Size and Espin Expression in Principal Cells of the Adult Rat Epididymis Are Regulated by Androgens

Principal cells of the epididymis are the most prominent cell type and are noted for an apical cell surface studded with microvilli. The latter contain channel proteins that condition the microenvironment of epididymal lumen and promote sperm maturation; however, the regulation of the structure and integrity of microvilli is not well known. Espins are a family of proteins implicated in microvillar growth. The objectives of this study were to assess the regulation of espin in epididymal principal cells both in vitro and in vivo. Treatment of immortalized rat caput epididymal (RCE) cells with increasing doses of a homogenized testicular extract revealed a dose-dependent increase in the size of microvilli. Reverse transcriptase-polymerase chain reaction (RT-PCR) of adult rat epididymal RNA using espin-specific primers indicated the presence of a band at about 290 base pairs (bp) in all regions. Western blot analysis using affinity-purified espin antibody confirmed the presence of an approximately 110-kDa band in the epididymis, corresponding to espin isoform 1. In adult rats, immunocytochemistry revealed espin expression over principal cells. In orchidectomized rats, espin expression was significantly reduced, whereas ligation of the efferent ducts resulted in a decrease of espin expression but not to the extent of orchidectomy. The fact that espin expression was restored to control levels in orchidectomized rats supplemented with high levels of testosterone indicated that its expression was dependent on androgens and not on other lumicrine factors derived from the testis. Taken together, these data indicate that espin is expressed in the epididymis and is regulated by androgens.

Segment boundaries of the adult rat epididymis limit interstitial signaling by potential paracrine factors and segments lose differential gene expression after efferent duct ligation

The epididymis is divided into caput, corpus and cauda regions, organized into intraregional segments separated by connective tissue septa (CTS). In the adult rat and mouse these segments are highly differentiated. Regulation of these segments is by endocrine, lumicrine and paracrine factors, the relative importance of which remains under investigation. Here, the ability of the CTS to limit signaling in the interstitial compartment is reviewed as is the effect of 15 days of unilateral efferent duct ligation (EDL) on ipsilateral segmental transcriptional profiles. Inter-segmental microperifusions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGFA) and fibroblast growth factor 2 (FGF2) increased phosphorylation of mitogen activated protein kinase (MAPK) in segments 1 and 2 of the rat epididymis and the effects of all factors were limited by the CTS separating the segments. Microarray analysis of segmental gene expression determined the effect of 15 days of unilateral EDL on the transcriptome-wide gene expression of rat segments 1-4. Over 11,000 genes were expressed in each of the four segments and over 2000 transcripts in segment 1 responded to deprivation of testicular lumicrine factors. Segments 1 and 2 of control tissues were the most transcriptionally different and EDL had its greatest effects there. In the absence of lumicrine factors, all four segments regressed to a transcriptionally undifferentiated state, consistent with the less differentiated histology. Deprivation of lumicrine factors could stimulate an individual gene's expression in some segments yet suppress it in others. Such results reveal a higher complexity of the regulation of rat epididymal segments than that is generally appreciated.

HOXBES2: A Novel Epididymal HOXB2 Homeoprotein and Its Domain-Specific Association with Spermatozoa1

The sperm from the testis acquires complete fertilizing ability and forward progressive motility following its transit through the epididymis. Acquisition of these characteristics results from the modification of the sperm proteome following interactions with epididymal secretions. In our attempts to identify epididymis-specific sperm plasma membrane proteins, a partial 2.83-kb clone was identified by immunoscreening a monkey epididymal cDNA library with an agglutinating monoclonal antibody raised against washed human spermatozoa. The sequence of the 2.83-kb clone exhibited homology to the region between 1 and 1097 bp of the homeobox gene, Hoxb2. This sequence was found to be species conserved, as revealed by RT-PCR analysis. To obtain a full-length clone of the sequence, 5' RACE-PCR (rapid amplification of cDNA ends PCR) was carried out using rat epididymal RNA as the template. It resulted in a full-length 1.657-kb cDNA encoding a 32.9-kDa putative protein. The protein designated HOXBES2 exhibited homology to the conserved 61-amino acid homeodomain region of the HOXB2 homeoprotein. However, characteristic differences were noted in its amino and carboxyl termini compared with HOXB2. A putative 30-kDa protein was detected in the tissue extracts from adult rat epididymis and caudal spermatozoa, and a 37-kDa protein was detected in the rat embryo when probed with a polyclonal antibody against HOXB2 protein. Multiple tissue Western blot and immunohistochemical analysis further indicated its expression in the cytoplasm of the principal and basal epithelial cells, with maximal expression in the distal epididymal segments. Northern blot analysis detected a single approximately 2.5-kb transcript from the adult epididymis. Indirect immunofluorescence localized the protein to the acrosome, midpiece, and equatorial segments of rat caudal and ejaculated human and monkey spermatozoa, respectively. In conclusion, we have identified and characterized a novel epididymal homeoprotein different from HOXB2 protein and hereafter referred to as HOXBES2, (HOXB2 homeodomain containing epididymis-specific sperm protein) with a probable role in fertilization.

Histological changes of the testis and epididymis in adult rats as a result of Ley dig cell destruction after ethane dimethane sulfonate treatment: a morphometric study

To quantitatively study the histological changes of the testis and epididymis as a result of a drastic reduction of testosterone secretion. Fourteen adult Sprague-Dawley rats were injected intraperitoneally with ethane dimethane sulfonate (EDS, 75 mg/kg) and the same number of animals were injected with normal saline as a control. At days 7 and 12 (after treatment), respectively, half of the animals from each group were killed. The testes and epididymides were removed and tissue blocks embedded in methacrylate resin. The cell number per testis was estimated using the stereological optical disector and some other parameters were obtained using other morphometric methods. The EDS treatment resulted in an almost complete elimination of Leydig cells but had no effect on the numbers of Sertoli cells per testis. At day 7 after EDS treatment, many elongated spermatids were retained in the seminiferous epithelium and many round spermatids could be seen in the epididymal ducts. At day 12, a looser arrangement of spermatids and spermatocytes became evident, with apparent narrow empty spaces being formed between germ cells in an approximately radial direction towards the tubule lumen; the numbers (per testis) of non-type B spermatogonia and spermatocytes were similar to controls, whereas that of type B spermatogonia increased by 59%, and that of early round, elongating and late elongated spermatids decreased by 37%, 72% and 52%, respectively. The primary spermatogenic lesions following EDS administration were (i) spermiation failure and (ii) detachment of spermatids and spermatocytes associated with impairment in spermiogenesis and meiosis.

Expression, Localization, and Regulation of Inhibitor of DNA Binding (Id) Proteins in the Rat Epididymis

The epididymis is the site in which spermatozoa are matured and stored. Regional differences along the epididymis are essential for the establishment of the microenvironment required for germ cell maturation. Inhibitor of DNA binding (Id) proteins are transcription factors that modulate the functions of basic helix-loop-helix (bHLH) transcription factors and act by binding to and sequestering bHLH proteins; the latter act to regulate cellular proliferation and differentiation. The objectives of this study were to determine the mRNA expression and the immunocytolocalization of Id1, Id2, Id3, and Id4 in the epididymis of adult rats and to determine the Id3 protein expression profile in orchidectomized and in aged animals. We found that, at the mRNA level, Id proteins are expressed in a unique, region-specific manner along the epididymis. Id1 immunoreactivity is specific to myoid cells; the presence of Id2 is observed in clear cells, myoid cells, and in the apical region of principal cells. Id3 immunoreactivity is essentially confined to the nuclei of principal cells and myoid cells, whereas Id4 is observed mainly in myoid and narrow cells. Thus, Ids are localized to different cell types and are differentially expressed, at both the mRNA and protein levels, along the epididymis. Expression of Id3 is differentially regulated in response to orchidectomy along the epididymis. The fact that these regulators of gene expression are expressed in this manner may provide some insight into the differential expression of other genes that lead to region-specific differences along the epididymis, a hallmark of this tissue.

Induction of oxidative stress by lindane in epididymis of adult male rats

Lindane, an organochlorine pesticide, has been reported to induce reproductive abnormalities in male rats. The mechanism of action of lindane on male reproductive system remains unclear. In the present study we have sought to investigate the effect of lindane on antioxidant parameters and sialic acid levels of caput, corpus and cauda epididymis of adult male rats. Lindane (1, 5, and 50 mg/kg per day) was administered orally to adult male rats for 45 days. The animals were killed using anaesthic ether on the day following the last treatment. The body weight of the animals did not show significant change. However, the weights of caput, corpus and cauda epididymis decreased in lindane treated animals. Administration of lindane caused decrease in epididymal sperm count and motility. Sialic acid levels in the epididymis decreased significantly at 5 and 50 mg/kg dosage of lindane treatment. Significant decline in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase along with increase in hydrogen peroxide generation and lipid peroxidation were observed in lindane treated animals. In conclusion, lindane induces oxidative stress by decreasing the activities of antioxidant enzymes and sialic acid levels in the epididymis thereby causing impaired sperm function.

Identification of multiple claudins in the rat epididymis

The luminal environment of the epididymis is highly specialized with specific proteins, ions, pH, etc. required for sperm maturation. Tight junctions between epididymal principal cells are responsible for the formation of the blood-epididymal barrier, which regulates this luminal environment. Claudins (Cldns) are a recently discovered family of transmembrane proteins and are essential components of tight junctions. Previous work from our laboratory has demonstrated the presence and localization of Cldn-1 in all regions of the rat epididymis. The objective of this study was to determine the presence and localization of other Cldns in the epididymis. Using RT-PCR we have identified mRNA transcripts for Cldn-3 through -9 in each region of the adult rat epididymis. Immunolocalization of Cldn-3, Cldn-4, and Cldn-5 were done in adult as well as in 42- and 14-day-old rats. Cldn-5 in adult rats was localized exclusively in blood vessels of the interstitium. Cldn-3 was localized apically in the epididymal epithelium between adjacent principal cells throughout the epididymis, where tight junctions have been reported histologically. There were no differences in the localization of Cldn-3 in epididymides of rats at the different ages. In 14-day-old rats, Cldn-4 was localized all along the lateral plasma membrane between adjacent principal cells. The immunostaining was more pronounced in the proximal regions of the epididymis. In both 42-day-old rats and adults, Cldn-4 was localized primarily to apical tight junctions between principal cells and staining was more pronounced in the proximal region of the epididymis. Cldn-16 transcripts were also identified by RT-PCR. These transcripts were present in both proximal and distal regions of the epididymis of young (Day 14 and 21) animals, but only in the proximal (initial segment) region of the adult epididymis. These data indicate that epididymal tight junctions are composed of several Cldns, suggestive of a complex regulation of the blood-epididymal barrier.

Effect of piperine on the epididymis of adult male rats

To study the effect of piperine on the epididymal antioxidant system of adult male rats. Adult male rats were orally administered piperine at doses of 1 mg/kg, 10 mg/kg and 100 mg/kg body weight each day for 30 consecutive days. Twenty-four hours after the last treatment, the rats were weighed and killed with ether and the epididymis was dissected from the bodies. Sperm collected from the cauda region of the epididymis was used for the assessment of its count, motility and viability. Caput, corpus and cauda regions of the epididymis were separated and homogenized separately to obtain 10 % homogenates. The supernatants were used for the assays of sialic acid, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, lipid peroxidation and hydrogen peroxide generation. Body weight of the piperine-treated rats remained unchanged. The weights of the caput, corpus and cauda regions of the epididymis significantly decreased at dose of 100 mg/kg. Epididymal sperm count and motility decreased at 10 mg/kg and 100 mg/kg, and sperm viability decreased significantly at 100 mg/kg. Sialic acid levels in the epididymis decreased significantly at 100 mg/kg while significant decrease in the cauda region alone was observed at 10 mg/kg. A significant decline in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, along with an increase in hydrogen peroxide generation and lipid peroxidation were observed at 10 mg/kg and 100 mg/kg. Piperine caused a decrease in the activity of antioxidant enzymes and sialic acid levels in the epididymis and thereby increased reactive oxygen species levels that could damage the epididymal environment and sperm function.

Postnatal Expression of Aquaporins in Epithelial Cells of the Rat Epididymis1

The mammalian aquaporins (AQPs) are a family of 13 transmembrane channel proteins that are involved in the transport of water in numerous organs. In the male excurrent duct, the movement of fluid and solutes across the epithelium is essential for establishing the proper luminal environment in which sperm mature and are stored. AQP9 is abundantly expressed in the efferent ducts, the epididymis, and the vas deferens, where it could represent an important apical pathway for transmembrane water and solute movement. However, other organs in which water transport is critical, including the kidney, the lung, or the eye, express several different AQPs with a cell-specific pattern. To undertake a systematic analysis of the expression of known AQPs in the postnatal and adult rat epididymis, we examined the expression of their respective mRNAs in epithelial cells isolated by laser capture microdissection (LCM), and we determined their corresponding protein expression pattern by immunofluorescence and Western blotting. Our data show that, whereas AQP9 is the main AQP of the epididymis, the mRNA specific for Aqp2, 5, 7, and 11 are also expressed in epididymal epithelial cells. AQP5 protein colocalizes with AQP9 in the apical membrane of a subpopulation of principal cells in the corpus and cauda regions. Aqp2 mRNA was detected in epithelial cells after the second postnatal week and the amount significantly increased up to adulthood. However, AQP2 protein was detected only in the distal cauda of young rats (between the second and fourth postnatal week). No AQP2 protein was detected in the adult epididymis, indicating that posttranscriptional mechanisms are involved in the regulation of AQP2 expression. In addition, epididymal epithelial cells express significant amounts of the mRNAs coding for AQP7 and 11. No mRNA or protein for AQPs 0, 4, 6, and 8 were detectable in epithelial cells, and Aqp1 was detected in whole epididymal samples, but not in epithelial cells. Thanks to the recent development of microdissection technologies, our observations suggest that epididymal epithelial cells express several members of the AQP family with a region-specific pattern. AQPs may be involved not only in the transepithelial transport of water in the epididymis but also in the postnatal development of this organ, as suggested by the differential expression of AQP2.