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PubMed1994

A testis-specific promoter in the rat vasopressin gene.

In the rat testis, the vasopressin gene is transcribed into precursor RNAs that are processed into a number of mature transcripts. One of these transcripts has a structure identical to that of the hypothalamic RNA that encodes the vasopressin prepropeptide, but is present at such low levels that it can only be detected by the polymerase chain reaction. Other vasopressin-like RNAs are derived from differential splicing events that join transcribed sequences between 3 and 9 kilobases upstream of the hypothalamic transcription start site to exons corresponding to II and III of the hypothalamic-type RNA. Here we describe the sequence of a testis-specific promoter and the exon structure of its transcription unit. We show that an in vitro synthesized RNA corresponding to the longer testicular vasopressin gene-derived transcript is not able to act as a template for protein synthesis in two different cell-free lysates. As attempts to localize the vasopressin-gene derived RNAs to particular cell types in the testis by in situ hybridization have consistently failed, we have used indirect methods. Three different procedures were used to effect germ cell depletion in adult male rats. Acute heat treatment of the testis, chronic ingestion of hydroxyurea, and chronic vitamin A deficiency all reduced the level of the aberrant testicular vasopressin-gene derived RNAs, indicating that their expression is closely associated with the integrity of germ cells and ongoing spermatogenesis.

Animals↗
PubMed1978

Intratesticular grafts: the testis as an exceptional immunologically privileged site.

The testis is an immunologically privileged site despite a normal lymphatic drainage, whereas the anterior chamber of the eye is a privileged site because it lacks normal lymphatics. Parathyroid grafts were transplanted between several strains of inbred rats (Buffalo leads to Lewis and Lewis X Brown Norway F1 leads to Lewis). Allografts were placed in the testis, thigh muscle, prostate, lymph nodes, anterior chamber of the eye and adrenal gland. The survival of intratesticular allografts also was tested in animals whose pituitary gonadotropins were suppressed by testosterone and estradiol implants. The effects of steroid implants were documented by measuring testosterone and progesterone concentrations in the serum and whole testis homogenates of these animals. Allograft survival was judged by fasting plasma calcium concentrations. The data show that 1) the adrenal is included among naturally occurring immunologically privileged sites, 2) the prolonged survival of intratesticular allografts may be related to the local production of steroid hormones, although allograft survival is not critically dependent on pituitary gonadotropins and 3) temperature differences and a high zinc concentration within the testis are not important to allograft survival.

Adrenal Glands↗
PubMed1979

A subset of trout testis nucleosomes enriched in transcribed DNA sequences contains high mobility group proteins as major structural components.

Mononucleosomes greatly enriched in non-histone proteins were prepared by limited digestion of testis nuclei with micrococcal nuclease. Five to fifteen per cent of the chromatin was solubilized and could be separated by adjustment to 0.1 M NaCl, into a soluble fraction MN1, consisting of mononucleosomes containing the four inner histones and the small basic non-histone, H6, associated with a 140-base-pair DNA fragment. H1 was notably absent in MN1. The fraction insoluble in 0.1 M NaCl (MN2) comprised a mixture of mono-, di-, tri-, and oligosomes. MN2 monosome fraction contained the four inner histones plus H1 and lacked H6 and the length of its DNA was 170 base-pairs. Previous work had shown that limited micrococcal nuclease digestion of trout testis nuclei released a great proportion of the non-histone protein, high mobility group protein T (HMG-T). It seems likely that HMG-T is the major non-histone protein located in the linker regions of a subset of nucleosomes containing the non-histone protein H6 as a major structural component. Moreover, the presence of HMG-T renders this subset of nucleosomes very sensitive to micrococcal nuclease. Hybridization experiments were performed to demonstrate that the DNA from MN1 monosomes corresponds to a subset of the trout testis genome. This DNA subset is greatly enriched in sequences that are present in cytoplasmic RNA. Chromatin subunits enriched in their content of H6 and HMG-T could also be obtained by limited digestion of trout testis chromatin with DNase II followed by precipitation with MgCl2.

Animals↗
PubMedDate not supplied

[Papillary adenocarcinoma of the rete testis. Report of a case].

OBJECTIVES: Another case of adenocarcinoma of the rete testis is described and the literature on this uncommon tumor type reviewed. METHODS/RESULTS: The clinical features, pathological findings and treatment of adenocarcinoma of the rete testis in a 72-year-old male are presented. CONCLUSIONS: Adenocarcinoma of the rete testis is a rare tumor type; few cases have been reported in the literature. Although treatment is primarily by surgery, recognition of new cases will provide further insight into this primary tumor of the rete testis.

Adenocarcinoma, Papillary↗
PubMed1994

Localization and purification of serum albumin in the testis of Xenopus laevis.

The distribution of serum albumin is of interest in the Xenopus (X.) laevis testis, since albumin is probably a major protein that binds testosterone (T) in the plasma and interstitial fluid. This study was undertaken to determine the localization and purification of serum albumin in the X. laevis testis. The interstitial tissue and spermatogenia immunoreacted strongly with a sheep antiserum raised against X. laevis albumin. A weak staining was also seen in spermatocytes and early spermatids, but there was no staining in Sertoli cells. In order to clarify whether serum albumin was really localized on the surface of testicular cells in the X. laevis testis, a membrane-rich fraction was prepared from testes and extracted with 0.6 M KCl. The KCl extract was then subjected to gel filtration, ammonium sulfate precipitation and high-performance liquid chromatography (HPLC). A protein with M(r) = 74 kD was obtained by this procedure and its NH2-terminal amino acid sequence was determined. The sequence of the first 19 amino acids was DTDADXXKXIADVYTALTE, suggesting that this protein was identical to serum albumin (M(r) = 74 kD). When the membrane fraction of blood cells in this animal was handled in the same manner, no appreciable amount of albumin was detected. These results suggest that the 74 kD serum albumin, possibly associated with bound T, may play an important role in the differentiation of germ cells during spermatogenesis of X. laevis testis.

Amino Acid Sequence↗
PubMedDate not supplied

Long-term alterations in the permeability of the blood-testis barrier following a single intratesticular injection of dilute aqueous glycerol.

The mechanism whereby glycerol exerts its antispermatogenic action is not known. The objective of this study was to determine, with the use of [3H]inulin and [125I]albumin by in vivo and in vitro methods, whether glycerol exerts its effect by altering the permeability of the blood-testis barrier (BTB). Adult male rats received a single intratesticular injection of either glycerol (10% or 20%; treated) or saline (control), and 2, 4, 8, 26, and 56 weeks after treatment, either [3H]inulin or [125I]albumin was administered either by infusion or directly to the testicular tissues. Radioactivity was measured in testicular tissue, rete testis fluid, and seminiferous tubular fluid. Following in vivo administration, the uptake of [3H]inulin by seminiferous tubules, rete testis fluid, and seminiferous tubule fluid was significantly greater in the treated than in the control testes at all times after treatment. Radiolabeled inulin, injected into isolated testes or added to medium in which isolated tubules were incubated, accumulated at significantly higher levels in the seminiferous tubule compartment of treated than control tissues. Rete testis fluid from treated testes, collected by micropuncture following efferent duct ligation, contained about 5- to 13-fold more radioactivity than fluid from controls. Following infusion of 50 microCi of [125I]albumin into the jugular vein, the accumulated radioactivity was significantly greater in testicular and epididymal tissues and in the seminiferous tubule fluid from treated than from control animals. In all experiments the significant differences between treated and control were maintained during the period of 2-56 weeks following glycerol treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1993

[Echographic evaluation of the undescended testis beyond the therapeutically useful period. Echopattern and testicular volume].

Echotomography and C.T. scan are the most common Imaging Techniques to study undescended testis: the echotomography for the inguinal, crural, perineal and penile localization; C.T. scan for the abdominal localization. The aim of this study was to evaluate morphological and volumetric alterations of testis in pre- and post-puberal patients with echotomography and C.T. scan. 65 patients were divided in two groups on the basis of age: group 1 (5-13 yrs; n = 46) and group 2 (> 13 yrs; n = 19). The volumetric and echo-structural alterations were more frequent in group 2 than in group 1. In group 1 a significant difference was observed between the incidence of echo-structural (35%) and volumetric (65%) alterations. A retained testis shows increased morphological alterations by aging. On the basis of these results we can conclude that in the group 1 the volumetric analysis is more reliable than the echo-structural analysis to evaluate testis "well-state".

Adolescent↗
PubMedDate not supplied

Neonatal goitrogen treatment increases adult testis size and sperm production in the mouse.

Male rats made hypothyroid during neonatal life show unprecedented increases in adult testis size and daily sperm production (DSP). To determine if this effect was unique to the rat or could also be demonstrated in other species, we examined the effects of neonatal treatment with the reversible goitrogen 6-propyl-2-thiouracil (PTU) on adult testis size and function in the mouse. Male Swiss-Webster mice were untreated (control) or given PTU by adding 0.1% (w/v) to their mother's water from birth to day 25 postpartum. All pups were then weaned and given no further treatment. Sertoli cell proliferation was examined using tritiated thymidine autoradiography in some control and treated mice at 0, 5, 10, 15, 20, and 25 days, while the remainder were killed at 90 days to determine a variety of reproductive parameters. Neonatal PTU treatment decreased growth; body weight of treated mice at 4 weeks of age was 57% less than controls. Treated mice grew rapidly following cessation of PTU treatment, although their weights never equalled controls, remaining 17% smaller at 90 days of age. At 90 days of age, testis weight and DSP were increased by approximately 30% and 50%, respectively, in PTU-treated mice compared to controls. Despite the increased testis weight and function, serum testosterone concentrations were not different in control and treated mice. Testicular and epididymal histology in treated mice was similar to controls, while epididymal sperm in treated mice were motile and morphologically normal. Sertoli cell proliferation was altered in treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Cloning and identification of testis-specific transcription elongation factor S-II.

A new S-II cDNA clone was isolated from a rat testis library. This cDNA contained an open reading frame encoding 299 amino acid residues. The deduced amino- and carboxyl-terminal regions were very similar with those of Ehrlich cell S-II, which we reported previously, but the sequence of the intervening 46 amino acid residues was unique. This new S-II was expressed in the testis but not in the other rat tissues examined, suggesting that it was a testis-specific S-II. Recombinant testis-specific S-II produced in Escherichia coli was shown to stimulate RNA polymerase II.

Amino Acid Sequence↗
PubMed1993

[Studies on a radioligand-receptor binding assay of human chorionic gonadotropin in rat testis].

A radioligand-receptor binding assay for human chorionic gonadotropin (HCG) has been established with cell membranes preparation of rat testis. Partially purified cell membranes preparation was prepared from rat testis by sucrose density gradient ultracentrifuge. The binding assay was performed by incubating 125I-HCG with rat testis cell membranes preparation at 30 degrees C for 1.5 h in a total incubation volume of 0.5 ml. Scatchard plot analysis for the binding assay revealed a linear binding plot and yielded a bound capacity of testis cell membranes receptors of 0.36 x 10(-12) mol/micrograms protein. KD of 0.45 x 10(-10) mol/L. Hill coefficient was 0.976. Studies on the kinetics of the reaction of radioligand-receptor binding showed that the mean values for the association rate (k1) and dissociation constants (k2) were individually 0.41 x 10(-3) pmol/min and 2.12 x 10(-3) pmol/min; the dissociation plot was two-phase, with 15 x 10(-3) pmol/min of fast-phase and 1.5 x 10(-3) pmol/min of slow-phase.

Animals↗
PubMed1993

Germ cell beta-chimaerin, a new GTPase-activating protein for p21rac, is specifically expressed during the acrosomal assembly stage in rat testis.

Diverse GTPase-activating proteins (GAPs) for the p21rho subfamily were detected by a novel overlay assay (Manser, E., Leung, T., Monfries, C., Teo, M., Hall, C., and Lim, L. (1992) J. Biol. Chem. 267, 16025-16028), with some GAPs being tissue-specific. Using a PCR strategy exploiting conserved regions common to rho/rac-GAPs, we have isolated a rat testis cDNA encoding a 34-kDa rac-GAP termed beta-chimaerin, as it was highly related to n-chimaerin, containing both a GAP domain (77% identity) and the phorbol ester-binding region (93% identity). beta-Chimaerin mRNA is expressed exclusively in the testis at the onset of sexual maturation. In situ hybridization and cell fractionation analyses show beta-chimaerin mRNA expression to be stage-specific, paralleling acrosomal assembly at the late stage of spermatogenesis. A corresponding testis-specific 30-kDa rac-GAP was detected. The testis-specific and stage-dependent expression of this new member of the chimaerin family offer an alternative model system for investigating the functional role of this class of p21 GAPs, particularly in relation to cytoskeletal reorganization.

Acrosome↗
PubMedDate not supplied

Immunocytochemical localization of the Yf subunit of glutathione S-transferase P shows regional variation in the staining of epithelial cells of the testis, efferent ducts, and epididymis of the male rat.

Glutathione S-transferases (GSTs) are a family of isozymes that catalyze the conjugation of glutathione (GSH), a tripeptide found in all mammalian cells; this function plays a protective role, as the addition of GSH to an electrophile generally forms a less toxic product. The pi class of GSTs contains homodimers of the Yf subunit, also known as Yp or rat subunit 7; this subunit is found in high concentrations in the testis and epididymis. The objective of the present study was to localize immunocytochemically the Yf subunit in the testis and in the various regions of the epididymis using light, electron, and confocal microscopy. In the testis, immunoperoxidase staining was localized exclusively to Sertoli and Leydig cells. The low cuboidal epithelial cells of the rete testis and the sparse ciliated cells of the ductuli efferents were also immunoreactive. A distinct pattern of immunostaining for the Yf subunit was observed in the different regions of the epididymis. The proximal area of the initial segment showed intense reactivity localized to epithelial basal cells. Basal cells in the middle area of the initial segment were also reactive, as were a second unidentified population of cells located in the apical region of the epithelium. The epithelium, including both principal and basal cells, in the distal initial segment, intermediate zone, and proximal caput epididymidis showed a weak, moderate, or strong degree of reactivity, respectively. In the distal caput epididymidis, however, principal cells showed a checkerboard-like pattern of immunoreactivity, with some cells being intensely stained or faintly stained, whereas others were unreactive. Strikingly, in the corpus and proximal cauda epididymidis, intense immunostaining was localized exclusively over the epithelial basal cells. As viewed in the light and confocal microscope, the intensely stained basal cells showed extensive processes that covered most of the base of the epididymal tubule. Upon quantitation of the immunogold labeling density (the number of gold particles/microns2) in principal and basal cells of the different regions of the epididymis, we observed a sharp decline in immunogold labeling of principal cells coupled with a dramatic increase in labeling of basal cells as we progressed along the tissue, particularly in the transition from the caput to the corpus epididymidis. This study constitutes the first demonstration of a protein that is selectively expressed in epithelial basal cells of the corpus and proximal cauda epididymidis.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Abundant expression of translation initiation factor EIF-4E in post-meiotic germ cells of the rat testis.

BACKGROUND: Eukaryotic translation initiation factor EIF-4E is a key component in the regulation of translational efficiency of MRNAs and its increased expression may accelerate cell growth and division. EIF-4E has the potential to transform rat embryo fibroblast cells by cooperation with v-Myc or adenovirus E1A. Our previous study showed that a variety of tumor cells examined exhibited elevated levels of eIF-4E gene expression. Thus it is thought that overexpression of EIF-4E can result in aberrant growth and cell transformation. EXPERIMENTAL DESIGN: To characterize rat EIF-4E, a clone containing rat eIF-4E cDNA was isolated from a rat testis cDNA library by screening with a synthetic probe prepared by the reverse transcription-polymerase chain reaction (RT-PCR) method. Based on the conserved nucleotide sequences between mouse and human eIF-4E cDNA, two oligonucleotide primers for RT-PCR were synthesized chemically. The cloned cDNA was sequenced and used as a probe for analysis of the expression level of eIF-4E mRNA in normal, differentiated rat tissues by Northern blot analysis. In situ hybridization analysis with digoxigenin-labeled antisense eIF-4E RNA as a probe was carried out to identify the eIF-4E-expressing sites in rat tissues. In addition, to analyse the phosphorylation level of EIF-4E, the proteins were fractionated from rat tissues by affinity column chromatography followed by isoelectric focusing (IEF)-gel electrophoresis. RESULTS: The nucleotide sequence of the eIF-4E cDNA is highly conserved in human, rat, and mouse. Extraordinarily elevated expression, more than 50-fold compared with that in the adult rat prostate, of eIF-4E was observed in testicular germ cells of rats of reproductive age, which was much greater than that in any tumor cell lines examined so far. The amount of EIF-4E fractionated from the adult rat testis was approximately 10 times higher than that from the adult rat liver. At least half of the purified testicular EIF-4E proteins were phosphorylated, a ratio similar to that in other rat tissues such as liver. In situ hybridization analysis demonstrated that elevated expression of eIF-4E mRNA was mainly observed in post-meiotic germ cells. CONCLUSIONS: Full activity of EIF-4E in translation requires the phosphorylation of the protein on a specific serine residue. Thus the elevated level of EIF-4E observed in the adult rat testis should be reflected in increase of the functional activity of EIF-4E. Based on the results of in situ hybridization analysis and characterization of EIF-4E, it was concluded that abundant EIF-4E in the testis may play an important role in spermatogenesis through translational regulation of stage-specific mRNAs during germ cell development.

Amino Acid Sequence↗
PubMed1996

Differential expression of glutathione S-transferase isoforms in compartments of the testis and segments of the epididymis of the rat.

Specific cell types of the mammalian testes demonstrate varying susceptibility to toxic insult by chemical agents. The mammalian testis is divided into two major compartments: seminiferous tubules, the site of spermatogenesis, and interstitium, which contains the Leydig cells. Glutathione S-transferase (GST) expression was examined in isolated compartments of the rat testis and in segments of the epididymis. Western blot analysis revealed the presence of GST class alpha, mu, and pi bands in each of the isolated compartments of the testis, and HPLC analysis of monomeric isoforms provided evidence for differential expression of multiple GST isoforms in testicular compartments. All major isoforms (e.g., forms 1, 2, 3, 4, 6, 7, 8, 9, and 11) were detected in the cytosol of whole testis. Isoform subunit 4 was the major form in the tubule, whereas isoform subunit 11 is the dominant form in the Leydig cells. Isoform subunits 3, 4, and 6 were enriched in the tubules as compared to interstitial or Leydig cells. The preferential action of reproductive toxicants at specific stages of aging may be due to an age-dependent expression of the activating or detoxifying enzymes in the reproductive tract. Therefore, the age-dependent expression of testicular GST isoforms was also examined. Expression of isoform subunits 2 and 4 displayed an age dependence, with the largest increase in these subunits occurring between ages 4 and 15 weeks. Isoform expression did not correlate with serum testosterone levels. HPLC analysis of the GST isoforms in the longitudinal segments of the epididymis and vas deferens revealed differential expression within these segments. Total GST protein and catalytic activity was highest in the caput epididymis and progressively decreased toward the vas deferens. Isoform subunit 2 was the major form expressed in the epididymis. The results of this study indicate that the GSTs are differentially expressed in testicular compartments and epididymal segments, and that this may contribute to susceptibility of different cell types to xenobiotic damage.

Animals↗
PubMed1997

Cyclophosphamide-induced structural and biochemical changes in testis and epididymidis of rats.

Effect of cyclophosphamide administration (100 mg/kg body weight, ip, for 5 consecutive days) was studied on albino rat testis and epididymidis after 3 and 6 weeks of treatment. Cyclophosphamide decreased testis and cauda epididymidal weights, sperm count, motile and viable spermatozoa and increased percentage of abnormal spermatozoa. The biochemical changes observed in the testis include increase in acid and alkaline phosphatase activities and decrease in proteins and activity of lactate dehydrogenase. The levels of lipids and total cholesterol were not affected. In the epididymidis cyclophosphamide caused decrease in the tubular diameter and increase in its epithelial height. It is concluded that cyclophosphamide brings about structural and biochemical changes in the testis and epididymidis.

Animals↗
PubMed1998

Viability of an inguinal testis after laparoscopic cauterization and transection of its blood supply.

A 25-month-old castrated horse was admitted for evaluation of stallion-like behavior. Twelve months earlier, bilateral cryptorchidism had been diagnosed, and the horse underwent a laparoscopic castration. At that time, the left testis was removed from the abdominal cavity, but the right testis, which was located in the inguinal ring, was left in place to undergo avascular necrosis after laparoscopic cauterization and transection of the testicular vasculature. On physical examination, an apparently clinically normal right testis was palpated within the scrotum. Administration of human chorionic gonadotropin resulted in an increase in testosterone concentration, which was consistent with the presence of viable testicular tissue. Surgery was performed to remove the testis.

Animals↗
PubMedDate not supplied

Mesotheliomas of tunica vaginalis testis of Fischer 344 (F344) rats treated with acrylamide: a light and electron microscopy study.

The incidence of spontaneous mesotheliomas of the tunica vaginalis testis, documented to be 1.3% in Fischer 344 rats can be increased by long term exposure to acrylamide. The light microscopic and electron microscopic features of tumors developing spontaneously in control animals were compared with those that developed in acrylamide treated animals to determine whether the tumors in the experimental group have any distinctive characteristics. The experimental group comprised three subgroups, i.e. animals exposed to acrylamide in three doses 0.1, 0.5 or 2.0 mg/kg/day over a period of 104 weeks. A total of 35 tumors were examined--7 in control group, 9 in low-dose group, 8 in mid-dose group and 11 in the high-dose group. Most tumors measured less than 1 cm in diameter in aggregate and approximately one-third of all tumors were of microscopic size, less than 5 mm in diameter. All tumors were classified as epithelial mesotheliomas. Three distinct microscopic patterns were recognized (papillary, tubular or solid). All tumors had papillary features, and focally showed some tubular or solid components. No ultrastructural differences were found between tumors of the four groups of animals. It was concluded that the tumors that developed in the tunica vaginalis testis of acrylamide treated animals do not differ morphologically from those that developed spontaneously in control animals. Cellular uniformity, small size of lesions and the absence of perotoneal seeding and metastasis suggests that the mesotheliomas of tunica vaginalis testis of Fischer 344 rats in this study were benign and equivalent to human benign mesothelioma of tunica vaginalis testis or adenomatoid tumors.

Acrylamide↗
PubMed1975

Permeability of selected drugs and chemicals across the blood-testis barrier of the rat.

Physiological studies by Setchell and others have described the existence of a blood-testis barrier (BTB) surrounding the seminiferous tubules of the mammalian testis. These studies were initiated to better define the role of the BTB with regard to the penetration of exogenous chemicals to male germ cells. The rete testis was cannulated in rats and fluid was collected. Test chemicals or drugs were usually administered by continuous i.v. infusion. Permeability of nonelectrolytes of various molecular sizes, acidic compounds with varying partition coefficients and pKalpha values, such as salicylic acid, barbiturates, and sulfonamides, across the BTB were studied. Permeability of nonelectrolytes was demonstrated to be dependent upon their molecular size, suggesting bulk flow through water-filled pores. On the other hand, permeability of acidic drugs with varying pKalpha values depended upon their partition coefficients. Transport of these chemicals from blood to seminferous tubules closely resembled their transport from blood to cerebrospinal fluid. It appears that the BTB is a complex multicellular system composed of membranes surrounding the semiferous tubules and the several layers of spermatogenic cells organized within the tubules, which restrict the permeability to the male germ cells of many foreign compounds. This must be borne in mind when extra-polating data from in vitro mutagenic test systems to man.

Animals↗