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PubMed1996

Molecular cloning and developmental expression of mouse p130, a member of the retinoblastoma gene family.

With sequence homology to the SV40 T antigen-binding domain of the retinoblastoma protein (Rb), p107 and p130 constitute two additional members of the Rb family. To explore the potential function of p130 in mouse development, we cloned the full-length mouse cDNA for p130 and characterized p130 mRNA expression in mice. The deduced mouse p130 protein sequence shares a higher degree of similarity with mouse p107 than with mouse Rb. In adult mice, p130 mRNA is found in all tissues examined. Levels of p130 mRNA vary among different adult tissues, with the highest level in testis. Within testis, p130 mRNA is found predominantly in Leydig cells. Additionally, p130 expression in testis correlates with sexual maturation, suggesting p130 is important for the development of testis and, in particular, Leydig cells. In situ hybridization shows that in post coitus day 12.5 and 14.5 mouse embryos, distribution of p130 mRNA is quite uniform with the exception of a few tissues. Little differences in mRNA levels of either p130 or p107 were found between normal and Rb-deficient embryos, suggesting that p130 and p107 are expressed independently of Rb. Our data are consistent with the hypothesis that p130 and p107 do not compensate for the loss of Rb and support the view that p130 is related to, yet distinct from, the RB gene.

Aging↗
PubMed2005

Quantification of stem cell factor mRNA levels in the rat testis: usefulness of clusterin mRNA as a marker of the amount of mRNA of Sertoli cell origin in post pubertal rats.

Spermatogenesis is a complex cellular process regulated by gonadotrophins and local cell-cell interactions. Stem cell factor (SCF) is one of the paracrine factors, produced by the Sertoli cells, involved in the local regulation of spermatogenesis. Measurement of its testicular level is important for addressing its role in testis physiopathology. However, the relative cell composition of experimental and pathological testis samples may lead to misinterpretation in relating SCF mRNA levels to the amount of RNA extracted from the whole tissue sample. Taking into account the relative RNA content of Sertoli cell origin should provide more significant data. In the present study, three sets of experiments were intended for modifying the proportion of RNA of Sertoli cell origin in RNA extracted from whole testis tissue samples: during postnatal development; following methoxy-acetic acid (MAA) administration; and after injecting a long-acting gonadotrophin-releasing hormone agonist (GnRHa). In a first step, we demonstrated clusterin mRNA level stability in purified Sertoli cell preparations between 20 days and adulthood, and following MAA or GnRHa treatment. In a second step, we used a competitive RT-PCR assay to measure SCF and clusterin mRNA levels and expressed the amount of SCF mRNA relative to the amount of clusterin mRNA under the above experimental conditions. The SCF/clusterin mRNA level ratio was found to remain roughly stable from 20 days post-partum to adulthood; i.e. during the development of spermatogenesis. MAA administration led to an overall increase in the SCF/clusterin mRNA level ratio between 7 and 14 days after administration, consistent with the replenishment of the testis with pachytene spermatocytes and round spermatids. Conversely, after long-acting GnRHa injection, the SCF/clusterin mRNA level ratio decreased only slightly from day 21 onward. Hence, the present studies indicate that, under physiopathological conditions, the amount of clusterin mRNA is a good marker of the amount of RNA of Sertoli cell origin in testis samples at day 20 or later; different experimental alterations of spermatogenesis are associated with different patterns of SCF mRNA levels; the relationship between FSH and SCF in vivo is not as simple as that described in vitro.

Animals↗
PubMed1982

Genetically mediated resistance to naturally occurring aortic sclerosis in spontaneously hypertensive as against Sprague-Dawley and Wistar-Kyoto breeder rats.

Male and female, normotensive, Sprague-Dawley (S-D), Wistar-Kyoto (WKy), and spontaneously hypertensive rats (SHR) were bred repeatedly until the females had given birth to and nursed 6 litters of pups. At the close of the 2nd, 4th and 6th breeding, breeder males and females, along with celibate males and females of equal age, were killed. S-D and WKy breeder rats manifested progressively increasing adiposity and high blood pressure with each successive breeding; breeder SHR showed mild exacerbation of their pre-existing high blood pressure. Adrenocortical hyperplasia and thymus-gland involution suggested increasing pituitary-adrenal activity in breeder rats. Circulating aldosterone levels decreased with repeated breeding in parallel with increased deoxycorticosterone and corticosterone secretion. The repeatedly bred normotensive rats manifested worsening aortic sclerosis as against little or no aortic sclerosis in the repeatedly bred SHR. Breeder SHR developed fibrinohyalin intimal lesions limited exclusively to the arterioles of the testis and ovary. Virgin rats did not develop any vascular disease. It is suggested that a diverse spectrum of adrenal steroids in breeder HSR combined with genetic direction control the morphogenesis of arterial disease in breeder SHR.

Animals↗
PubMed2000

Enzyme assay for 5alpha-reductase type 2 activity in the presence of 5alpha-reductase type 1 activity in rat testis.

The relative abundance and physiological role of 5alpha-reductase (5alphaR) isoforms in rat testis, in particular 5alpha-reductase Type 2 (5alphaR2) are poorly understood. Investigation of 5alphaR2 activity using enzyme kinetic studies was hampered by the high concentrations of 5alpha-reductase Type 1 (5alphaR1) in rat testis. Therefore, an assay was developed which exploited the differences in pH optima of the two isoforms. The 5alphaR assays measured the conversion of 3[H]-testosterone to 5alpha-reduced metabolites (dihydrotestosterone+3alpha-Androstanediol) at pH 5.0 and 7.0. To compensate for the overlap of 5alphaR1 activity at pH 5.0, the amount of 5alphaR1 activity at pH 5.0 was determined by measuring recombinant rat 5alphaR1 expressed in COS-7 cells at pH 5.0 and 7.0. The amount of activity at pH 5.0 that was attributed to 5alphaR1 was determined to be 12.4+/-1.4% (mean+/-S.D., n=14). The 5alphaR2 assay was validated by determining recombinant rat 5alphaR2 activity in the presence of recombinant rat 5alphaR1 activity in COS cells. A 99.3+/-14.7% recovery of 5alphaR2 activity was obtained when comparing 5alphaR2 activity recovered versus activity added. 5alphaR1 and 5alphaR2 activities were then assayed in rat testis extracts from 30, 75 and 147 days. Both isoforms markedly declined (50-100-fold) over this age range, with 5alphaR1 as the predominant isoform. In conclusion, an enzymatic assay that detects 5alphaR2 activity in the presence of high concentrations of 5alphaR1 was developed and is applicable in the measurement of 5alphaR2 activity in rat testis.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1986

Requirement of serum components for the preservation of primordial germ cells in testis cords during early stages of testicular differentiation in vitro in the mouse.

Mouse gonadal primordia were isolated from embryos on the 11th day of gestation and cultured in vitro. They developed into either testes or ovaries after 7 days of culture in Eagle's minimum essential medium (MEM) supplemented with horse serum, whereas they did not differentiate in MEM alone. We studied how serum components are required for testicular development in vitro. When gonadal primordia were cultured in MEM alone for the first 1-3 days and subsequently in MEM supplemented with serum, testis cords developed while germ cells disappeared or only a few remained in the testis cords. In contrast, when serum was present in the medium during the first day of culture and omitted thereafter, germ cells were retained within testis cords. These results suggested that some serum component(s) is specifically required by germ cells independent of testis cord organization. Of more than 10 serum components tested, low and very low density lipoprotein fractions increased the number of germ cells in testicular explants.

Animals↗
PubMed2002

Role of FSH, numbers of FSH receptors and testosterone in the regulation of inhibin secretion during the seasonal testicular cycle of adult rams.

The regulation of inhibin secretion has not been elucidated fully in male ruminants. The aim of this study was to determine the relative importance of FSH and testosterone concentrations, and FSH receptors, in the control of secretion of immunoactive inhibin in rams. In Expt 1, temporal changes in hormone concentrations and testicular FSH binding were determined for two groups of rams (n = 4) kept under opposite, alternating 4 month periods of long (16 h light:8 h dark) and short (8 h light:16 h dark) days. Testicular biopsies (1-2 g) were collected when the testes were regressed, redeveloping, redeveloped and regressing. In Expt 2, separate groups of rams (n = 4) kept under natural photoperiod (latitude 45 degrees 48 minutes N) were designated as controls or passively immunized (for 3 weeks) with sufficient oestradiol antiserum to increase testosterone secretion without altering LH and FSH; this was done when the testes were regressed (non-breeding season) and redeveloped (breeding season). In both groups of rams (Expt 1), 'seasonal' increases in FSH concentrations began a few weeks earlier than did increases in inhibin concentrations. FSH reached maximum concentrations during testicular recrudescence, whereas numbers of FSH receptors in the testis and circulatory inhibin concentrations did not reach peak values until the testes were fully developed. Numbers of FSH receptors per testis, but not FSH concentration, were positively correlated (r = 0.65) with inhibin concentrations across the four stages of the testicular cycle. Near the end of testicular recrudescence early in the breeding season (Expt 2), relatively high FSH concentration was associated with increased abundance of FSH receptor mRNA (90%) and number of receptors (45%) in the testis and increased inhibin concentrations (50%), compared with when the testes were regressed. Moderate, physiological increases in testosterone secretion in immunized rams did not affect inhibin in either season. These results indicate that: (i) FSH stimulation of immunoactive inhibin secretion by Sertoli cells as testes recrudesce is via increases in secretion (early) and cognate receptors (late); (ii) FSH upregulates the synthesis of its own receptor late in recrudescence; and (iii) the positive correlation (r = 0.70) observed between circulatory testosterone and immunoactive inhibin does not reflect a causal relationship.

Analysis of Variance↗
PubMed1994

Developmental regulation of the thyroid hormone receptor alpha 1 mRNA expression in the rat testis.

The multiplicity of thyroid hormone (TH) effects appears to be mediated by two TH receptors (THRs) encoded by two genes, alpha and beta, and, perhaps, by their various isoforms. The expression of THR beta is correlated with the presence of high affinity binding sites for TH, and all the mutations which cause the syndrome of generalized thyroid hormone resistance occur in THR beta. The function of THR alpha has not been clearly defined as yet. Another enigma in TH action is the effect on the testis. It has been shown that the testis of the adult rat does not respond to TH as measured by an increase in oxygen consumption. Furthermore, it has not been possible to demonstrate the presence of a nuclear high affinity binding site for TH in adult testis. To resolve these problems were measured the levels of THR alpha, its nonhormone binding variant, and THR beta mRNA in the testis at various stages of development. We discovered that the beta-message is absent at all times, whereas the alpha-message is expressed only from fetal through prepubertal stages and is absent in adult testis. THR alpha, but not the beta-mRNA, was detected in immature Sertoli cells in culture, and neither was found in adult Sertoli cell-enriched cultures. Furthermore, THR alpha and its variant mRNA was found, using in situ hybridization, in the seminiferous cords and seminiferous tubules of fetal and prepubertal testis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Metachronous seminoma of the pineal region and right testis. Case report.

The case history of a 23-year-old patient suffering from germinoma of the pineal region, who later developed a seminoma of the right testis, is reported. The possibility that the testicular tumor was a metastasis from the pineal neoplasia appears unlikely. The question of whether the pineal germinoma represented a metastasis from an occult testicular seminoma or an autochthonous tumor is discussed. The latter hypothesis is considered the most likely. The present report appears to support the multiple primary origin of, at least some, germ cell tumors.

Adult↗
PubMed1997

[Polyorchidism: 2 case reports].

Polyorchidism is a rare anomaly with approximately 70 cases reported in literature. The exact explanation for the production of polyorchidism is not known, although several theories have been proposed, including anomalous appropriation of cells, initial longitudinal duplication of the genital ridge and transverse division of the genital ridge, either through some local accident of development of peritoneal bands. A functional classification based upon the embryogenic development is provided. Type I: the supernumerary testis lacks an epididymis and vas. The split-off part of the primordial gonad does not communicate with the mesonephric tubules from which the epididymis develops. Type II: the supernumerary testis is linked to the regular testis by a common epididymis and shares a common vas with it. The division of the genital ridge occurs in the region where the primordial gonads are attached to the mesonephric ducts, although the latter are not divided (incomplete division). Type III: the supernumerary testis has its own epididymis but shares the vas with the regular testis. This variant results from a complete transverse division of the genital ridge. In the majority of the reported cases, the patients are asymptomatic and have painless groin or testicular masses. Approximately 50% occur as maldescent or cryptorchidism, and about 30% are associated with indirect hernia. The remaining 20% are discovered variously in relation to torsion, or are associated with hydrocele, epididymitis, varicocele or infertility. Moreover, since there is a 20 to 40 fold increase in testicular malignancy in patients with cryptorchidism compared with the normal testis, tumours of the supernumerary testicles are not unusual. We reported two cases of polyorchidism: the first patient is probably a longitudinal division of the genital ridge and the second is a completely duplication of the primordial gonads. The patients described vague, intermittent, testicular pain. Physical examination and the scrotal sonography and magnetic resonance revealed in the first patient a supernumerary testis in the right scrotal space and in the second a bilateral double testis. In conclusion we think that in the absence of any concomitant disorder and if testicular tumor can be ruled out by ultrasonography and magnetic resonance imaging, surgical exploration with biopsy is unnecessary.

Adult↗
PubMedDate not supplied

Effect of chloroquine on the formation of tight junctions in cultured immature rat Sertoli cells.

Adjoining immature Sertoli cells in the seminiferous epithelium form a tight junctional complex leading to the development of the blood-testis barrier. Protease and antiprotease activities have been implicated in the process of formation of tight junctions. Here, we report the effect of chloroquine, an antimalarial drug with antiprotease activity, on the development of intercellular tight junctions in cultured immature rat Sertoli cells. For positive control, the classical lysosomotropic agent ammonium chloride was used. Sertoli cells were seeded in serum-free defined medium at a density of 3 x 10(6) cells/0.64-cm2 well on Matrigel-covered Millicell-HA filters. Chloroquine at concentrations ranging from 25 to 100 microM was added to the outer chamber of the bicameral system on either day 1 or 7 of the culture. The formation of the tight junction was monitored by the measurement of the transepithelial resistance (TER) at 24-hour intervals using an impedance meter. TER in untreated controls was 50 ohms/cm2 on day 1; it increased progressively to 80 ohms/cm2 by day 7 and plateaued until day 12. The cells treated from day 1 with chloroquine also showed a dose-dependent progressive increase in TER until day 9, reaching 225 ohms/cm2 in cells treated with the 100 microM concentration. In comparison to controls, the increase in TER was significantly higher. In cells treated with chloroquine starting from day 7 of culture onwards, there was no observable difference in TER from the untreated control. These observations demonstrate that chloroquine and ammonium chloride increase the TER of immature Sertoli cells in the bicameral chamber.

Amines↗
PubMed2005

[Effects on development of the testicle in diet-induced obesity rats].

OBJECTIVE: We established diet-induced obesity animal model and observed the influence of obesity on testicle of the male rats. METHODS: Rats in model group were fed with fat-enriched diet for 6 weeks. We measured the body weight and the testis weight and observed the development of testicle by microscope, and compared with those of control group. Meanwhile, we measured the serum levels of testosterone (T) and estradiol (E2). RESULTS: The average body weight in model group rats was higher 29% than that in control group at 6 weeks old, 30% at 9 weeks old. We observed under microscope that most of the convoluted seminiferous tubule developed no good in model group, the 4 layer cells was sparse and the arrangement of them was not in order. The testosterone to estradiol ratios(T/E2) in model group was significant lower then that of control group (P < 0.05). CONCLUSION: The fat-enriched fat diet can induce obesity. It influenced the development of the testicle. This probably related to decrease of the testosterone to estradiol ratios.

Animals↗
PubMed1994

Effects of dietary zinc deficiency on the reproductive system of young male sheep: testicular growth and the secretion of inhibin and testosterone.

The effects of dietary zinc deficiency on testicular development in young Merino rams (initial live mass, 22 kg) were tested. Four groups of five rams were fed ad libitum with diets containing 4, 10, 17 or 27 micrograms Zn g-1. To control the effects of loss of appetite caused by zinc deficiency, a fifth group (pair-fed control) was fed the diet containing 27 micrograms Zn g-1, but the amount of feed offered was restricted to that eaten voluntarily by the zinc deficient (4 micrograms Zn g-1) rams they were paired with. After 96 days on the diets, epididymal and testicular masses did not differ significantly between the animals fed 10, 17 or 27 micrograms Zn g-1 ad libitum, but were significantly lower in pair-fed controls, and lowest in the zinc-deficient animals. Testicular responsiveness to LH, as measured by testosterone production, increased substantially in most rams as the experiment progressed, the only exception being the zinc-deficient group, in which the response to LH was lower than in any of the other groups. Testicular concentrations of zinc and testosterone were lower in the zinc-deficient animals than in all the other groups. Plasma inhibin concentrations fell as the experiment progressed in rams fed 17 and 27 micrograms Zn g-1 ad libitum, but not in the other groups. The pair-fed control rams had smaller seminiferous tubules and less lumen development than did the controls fed ad libitum (27 micrograms Zn g-1), which were similar to the animals fed 10 or 17 micrograms Zn g-1. In zinc-deficient rams, the tubule development was further retarded and the interstitial regions were more extensive than in the other groups. We conclude that the overall effect of zinc deficiency on testicular development is due to a combination of a non-specific effect (low gonadotrophin concentrations caused by the low feed intake) and a specific effect due to the lack of zinc. The zinc-specific effect is localized within the testis where it reduces the development of the capacity to produce testosterone, leading to low intratesticular concentrations of testosterone, a critical factor for the growth, development and function of the seminiferous tubules.

Animals↗
PubMed1975

Aspects of germinal cyst and sperm development in Poecilia latipinna (Teleostei: Poeciliidae).

The structure of the testis of Poecilia latipinna is described with particular reference to Sertoli cell-germ cell relationships during development and maturation of the germinal cyst. The cyst develops when primary spermatocytes become surrounded by a single layer of Sertoli cells at the testis periphery. As spermatogenesis and then spermiogenesis proceed, the cyst moves centrally in the testis toward the ducts comprising the vasa efferentia. In addition to being a structural part of the germinal cyst, the Sertoli cells phagocytize residual bodies cast off by developing spermatids and form an association with mature bodies cast off by developing spermatids and form an association with mature sperm, which resembles that observed in mammals, before the sperm are released into the vasa efferentia as a spermatozeugmata. The results of this investigation are discussed in view of what is known concerning testis structure in other teleosts and similarities between cell functions in teleosts and mammals. It is concluded that teleost Sertoli cells, teleost lobule boundary cells and mammalian Sertoli cells are homologous.

Animals↗
PubMed1997

Expression of the preoptic regulatory factor-1 and -2 genes in rat testis. Developmental and hormonal regulation.

Hormone-responsive peptides play a vital role in development and regulation of testicular function. The preoptic regulatory factors, porf-1 and porf-2, were originally discovered in the rat brain, but are also expressed in the rat and human testis. In the brain expression is age-related, hormone-responsive, region- specific, and gender-related, suggesting that porf-1 and porf-2 are involved in gender-specific brain development and function. Tissue-specific porf-1 and porf-2 mRNAs are also found in the testis and hypophysectomy may alter testicular porf-2 expression. It was thus of interest to further examine porf-1 and porf-2 expression in the testis to evaluate their potential as hormone-responsive peptides that regulate testicular development and function. Testicular expression of both porf-1 and -2 was analyzed as a function of maturational stage, aging and hypophysectomy by the solution hybridization/nuclease protection assay, and cellular location determined by in situ hybridization histochemistry. Expression was quantitatively compared in normal male rats at 15, 30 and 60 d (n = 4) and at 2, 6, 12, and 24 mo of age (n = 5). During development porf-1 is expressed at a constant level at 15, 30 and 60 d, then declines significantly with advancing age; levels at 24 mo are only 20% of those seen at 2 mo (p < 0.05). In contrast, porf-2 expression is highest at 15 d of age and steadily declines at 30 and 60 d, plateaus in the mature adult (6 and 12 mo), then exhibits an additional significant decline in the aged 24 mo animals (6 vs 24 mo, p < 0.05). Hypophysectomy of young adult rats at day 42 results in increased testicular expression 12 d later of both porf-1 (p < 0.05) and porf-2(p < 0.005) compared to intact 54-d-old rats (n = 5). In situ hybridization histochemistry confirms that both porf-1 and porf-2 are expressed in the mature testis at 60 d of age. Porf-2 mRNA is localized to immature germ cells including spermatogonia and primary spermatocytes. Porf-1 mRNA is associated with mature sperm and at low levels in the Sertoli cell cytoplasm surrounding spermatocytes. These data suggest that porf-2 is a pituitary hormone-responsive factor in the developing testis and that both porf-1 and porf-2 have cell-type specific functions in the germ cell compartment of the mature testis

Aging↗
PubMed1991

Male development of chromosomally female mice transgenic for Sry.

The initiation of male development in mammals requires one or more genes on the Y chromosome. A recently isolated gene, termed SRY in humans and Sry in mouse, has many of the genetic and biological properties expected of a Y-located testis-determining gene. It is now shown that Sry on a 14-kilobase genomic DNA fragment is sufficient to induce testis differentiation and subsequent male development when introduced into chromosomally female mouse embryos.

Animals↗
PubMed1982

Surgical treatment of undescended testes.

Surgical therapy of undescended testes is indicated when the testis is located in any site other than the scrotum, especially after unsuccessful hormonal treatment. If the testis can be palpated pre-operatively, a classical orchiolysis should always be carried out first, followed by orchiopexy. In the Sophia Children's Hospital orchiolysis and orchiopexy are always carried out following the techniques developed by Schoemaker. If the testis is not palpable, laparoscopy should be carried out to determine whether a testicle can be located intra-abdominally. If orchiolysis and orchiopexy would prove inadequate to achieve scrotal fixation due to shortness of the vasa spermatica, autotransplantation with microsurgical techniques can be carried out.

Child↗
PubMedDate not supplied

[Testicular graft on the chick embryo].

A testis from an 18-day-old chick embryo was transplanted into the extra-coelomic cavity of 3-4-day-old hosts. The embryos surviving at 17 days were sacrificed and their genital system was examined. Testis grafting produced inhibition of testicular development. Development of the female gonads was also inhibited. A more or less complete modification of sex was associated with this inhibition. The left ovary lost its cortex, but its medulla remained mostly ovarian in structure. The right gonad frequently acquired a typical testicular structure. These results confirm the possibility of obtaining sex reversal in the female chick embryo by testis grafting.

Animals↗