Influence of hormonal imbalance on the integrity of seminiferous epithelium in the testes of adult rats chronically exposed to letrozole and rats exposed to soya isoflavones during the prenatal period, lactation, and up to sexual maturity

The structural integrity of the germ cells in the seminiferous epithelium and the correct process of spermatogenesis are made possible by proteins that participate in the formation of different types of junctions. This study was performed on samples of the testes of 4 groups (2 experimental and 2 corresponding control) of male Wistar rats. In the first experimental group, the adult rats received letrozole - a nonsteroidal inhibitor of cytochrome P450 aromatase (P450arom). The second experimental group was exposed to soya isoflavones during the prenatal period, lactation, and up to sexual maturity. The aim of this study was to examine the immunoexpression of β-catenin, N-cadherin, occludin, connexin43, annexin V, and advanced glycation end products (AGE) in the seminiferous epithelium of rat testes with chronic estrogen deficiency and of rats exposed to soya isoflavones. Series of sections of the testes were stained using PAS and silver impregnation. Moreover, immunohistochemistry tests were performed. A semi-quantitative determination of protein immunoexpression was performed using Image J. The number of annexin V positive Sertoli cells per tubule were counted manually. Comparisons between the experimental and corresponding control groups were performed using a non-parametric Mann-Whitney U test. The most common alterations were prematurely sloughed germ cells in the lumen of the seminiferous tubules and invaginations of the seminiferous tubules. We observed a lower number of annexin V positive Sertoli cells and a lower expression of N-cadherin and occludin in the seminiferous epithelium of both groups of rats with hormonal imbalances. Moreover, a higher expression of AGE, a lower expression of connexin 43 and a lower amount of reticular fibers in the basal lamina of seminiferous tubules was present in rats treated with letrozole and a higher expression of β-catenin was found in rats exposed to soya isoflavones. The hormonal imbalance between androgens and estrogens resulted in a decreased number of annexin V positive Sertoli cells. This may be associated with a failed clearance of apoptotic germ cells that leads to disturbances in the blood-testis-barrier (BTB) by affecting the expression of junctional proteins in the seminiferous epithelium. Moreover, a decreased level of estrogens was also associated with an increased expression of AGEs and with a changed composition of basal lamina in the seminiferous tubules of rats. These changes could lead to germ cell sloughing and invaginations of the seminiferous tubules.

Venlafaxine-induced damage to seminiferous epithelium, spermiation, and sperm parameters in rats: A correlation with high estrogen levels

BACKGROUND

Venlafaxine (selective serotonin and norepinephrine reuptake inhibitor) use has increased worldwide. However, the impact of venlafaxine on testes and sperm parameters has not been investigated.

OBJECTIVES

We evaluated venlafaxine impact on testicular and sperm parameters and verified whether the changes are reversible.

METHODS

Animals from venlafaxine-35 days and venlafaxine-65 days groups received 30 mg/kg of venlafaxine for 35 days. Control-35 days and control-65 days received distilled water. In control-65 days and venlafaxine-65 days, the treatment was interrupted for 30 days. Sperm concentration, morphology, motility, and mitochondrial activity were analyzed. Number of step 19 spermatids (NLS), frequency of tubules with spermiation failure, Sertoli cells number, and TUNEL-positive germ cells were quantified. Testicular aromatase, connexin 43 (Cx43) immunoexpression, Cx43 protein levels, and Cx43 expression were evaluated. Either intratesticular testosterone or estrogen levels were measured.

RESULTS

Venlafaxine impaired sperm morphology, reduced sperm concentration, mitochondrial activity, and sperm motility. The frequency of tubules with spermiation failure and NLS increased in parallel to increased Cx43 immunoexpression; mRNA and protein levels; and aromatase, testosterone, and estrogen levels. An increase in germ cell death and decreased Sertoli cells number were observed. In venlafaxine-65 days, except for sperm motility, mitochondrial activity, Sertoli cells number, and germ cell death, all other parameters were partially or totally recovered.

CONCLUSION

Venlafaxine increases testosterone aromatization and Cx43. This drug, via high estrogen levels, disturbs Sertoli cells, induces germ cell death, and impairs spermiation and sperm parameters. The restoration of spermiation associated with the decreased Cx43 and hormonal levels in venlafaxine-65 days reinforces that high estrogen levels are related to venlafaxine-induced changes. The presence of damaged Sertoli cells, germ cell death, and low sperm motility in venlafaxine-65 days indicates that interruption of treatment for 30 days was insufficient for testicular recovery and points to a long-term estrogen impact on the seminiferous epithelium.

Disruption of androgen signaling during puberty affects Notch pathway in rat seminiferous epithelium

BACKGROUND

Onset of spermatogenesis at puberty is critically dependent on the activity of hypothalamic-pituitary-gonadal axis and testosterone production by Leydig cells. The aim of this study was to examine whether activation of Notch receptors and expression of Notch ligands and effector genes in rat seminiferous epithelium are controlled by androgen signaling during puberty.

METHODS

Peripubertal (5-week-old) Wistar rats received injections of flutamide (50 mg/kg bw) daily for 7 days to reduce androgen receptor (AR) signaling or a single injection of ethanedimethane sulphonate (EDS; 75 mg/kg bw) to reduce testosterone production. Gene and protein expressions were analyzed by real-time RT-PCR and western blotting, respectively, protein distribution by immunohistochemistry, and steroid hormone concentrations by enzyme-linked immunosorbent assay. Statistical analyses were performed using one-way ANOVA followed by Tukey's post hoc test or by Kruskal-Wallis test, followed by Dunn's test.

RESULTS

In both experimental models changes of a similar nature in the expression of Notch pathway components were found. Androgen deprivation caused the reduction of mRNA and protein expression of DLL4 ligand, activated forms of Notch1 and Notch2 receptors and HES1 and HEY1 effector genes (p < 0.05, p < 0.01, p < 0.001). In contrast, DLL1, JAG1 and HES5 expressions increased in seminiferous epithelium of both flutamide and EDS-treated rats (p < 0.05, p < 0.01, p < 0.001).

CONCLUSIONS

Androgens and androgen receptor signaling may be considered as factors regulating Notch pathway activity and the expression of Hes and Hey genes in rat seminiferous epithelium during pubertal development. Further studies should focus on functional significance of androgen-Notch signaling cross-talk in the initiation and maintenance of spermatogenesis.

Glyphosate-based herbicide exposure during pregnancy and lactation malprograms the male reproductive morphofunction in F1 offspring

One of the most consumed pesticides in the world is glyphosate, the active ingredient in the herbicide ROUNDUP®. Studies demonstrate that glyphosate can act as an endocrine disruptor and that exposure to this substance at critical periods in the developmental period may program the fetus to induce reproductive damage in adulthood. Our hypothesis is that maternal exposure to glyphosate during pregnancy and lactation in mice will affect the development of male reproductive organs, impairing male fertility during adult life. Female mice consumed 0.5% glyphosate-ROUNDUP® in their drinking water [glyphosate-based herbicide (GBH) group] or filtered water [control (CTRL) group] from the fourth day of pregnancy until the end of the lactation period. Male F1 offspring were designated, according to their mother's treatment, as CTRL-F1 and GBH-F1. Female mice that drank glyphosate displayed reduced body weight (BW) gain during gestation, but no alterations in litter size. Although GBH male F1 offspring did not exhibit modifications in BW, they demonstrated delayed testicular descent. Furthermore, at PND150, GBH-F1 mice presented a lower number of spermatozoa in the cauda epididymis and reduced epithelial height of the seminiferous epithelium. Notably, intratesticular testosterone concentrations were enhanced in GBH-F1 mice; we show that it is an effect associated with increased plasma and pituitary concentrations of luteinizing hormone. Therefore, data indicate that maternal exposure to glyphosate-ROUNDUP® during pregnancy and lactation may lead to decreased spermatogenesis and disruptions in hypothalamus-pituitary-testicular axis regulation in F1 offspring.

Sperm Release at Spermiation Is Regulated by Changes in the Organization of Actin- and Microtubule-Based Cytoskeletons at the Apical Ectoplasmic Specialization-A Study Using the Adjudin Model

The mechanism that regulates sperm release at spermiation is unknown. Herein, we used an animal model wherein rats were treated with adjudin, 1-(2,4-dichlorobenzyl)-1H-indazole-3-carbohydrazide, via oral gavage to induce premature release of elongating/elongated spermatids, followed by round spermatids and spermatocytes. Spermatid release mimicking spermiation occurred within 6 to 12 hours following adjudin treatment and, by 96 hours, virtually all tubules were devoid of elongating/elongated spermatids. Using this model, we tracked the organization of F-actin and microtubules (MTs) by immunofluorescence microscopy, and the association of actin or MT regulatory proteins that either promote or demolish cytoskeletal integrity through changes in the organization of actin microfilaments or MTs by coimmunoprecipitation. Adjudin treatment induced an increase in the association of (1) epidermal growth factor receptor pathway substrate 8 (an actin barbed-end capping and bundling protein) or formin 1 (an actin nucleator) with actin and (2) end-binding protein 1 (an MT stabilizing protein) with MT shortly after adjudin exposure (at 6 hours), in an attempt to maintain spermatid adhesion to the Sertoli cell at the apical ectoplasmic specialization (ES). However, this was followed by a considerable decline of their steady-state protein levels, replacing with an increase in association of (1) actin-related protein 3 (a branched actin nucleator that converts actin filaments into a branched/unbundled network) with actin and (2) MT affinity-regulating kinase 4 (an MT destabilizing protein kinase) with MTs by 12 hours after adjudin treatment. These latter changes thus promoted actin and MT disorganization, leading to apical ES disruption and the release of elongating/elongated spermatids, mimicking spermiation. In summary, spermiation is a cytoskeletal-dependent event, involving regulatory proteins that modify cytoskeletal organization.

Arsenic trioxide exposure impairs testicular morphology in adult male mice and consequent fetus viability

The acute promyelocytic leukemia (APL) is a rare disease, affecting 0.1/100,000 individuals globally. Despite significant advances in APL therapy, some patients still experience relapsed disease. Currently, arsenic trioxide (As₂O₃) was found to be effective in relapsed APL treatment and considered as standard treatment for these cases. However, it has been shown that exposure to As₂O₃ may exert adverse effects on the male reproductive system since this substance might also induce apoptosis of other important cell types including stem cells. Studies demonstrated that treatment with this metallic substance decreased plasma levels of testosterone and interfered with sperm parameters such as concentration, motility, and viability. In addition, As₂O₃ was found to produce significant damage to spermatocytes, which may be associated with testicular toxicity and consequent inhibition of spermatogenesis. The aim of this study was to determine sub-chronic treatment effects of As₂O₃ on sperm and testicular morphology, androgen receptor (AR) immunoreactivity in testes and epididymis, in addition to evaluation of fertility parameters in adult male mice. Thirty adult Swiss mice were divided into three experimental groups: control; received distilled water (vehicle) while treated received 0.3 or 3 mg/kg/day As₂O₃ subcutaneously, for 5 days per week, followed by 2 days of interruption, for 5 weeks. Results showed that As₂O₃ (1) decreased spermatozoa number, (2) produced seminiferous epithelium degeneration and exfoliation of germ cells tubule lumen (3) altered nucleus/cytoplasm proportion of Leydig cells and (4) reduced AR immunoreactivity in both Leydig and epithelial epididymal cells. Further, fetal viability tests demonstrated an increase in post-implantation loss in females that were mated with As₂O₃-treated males. Data indicate that As₂O₃ exposure altered the spermatogenic process and subsequently fetal viability.

Coordination of Actin- and Microtubule-Based Cytoskeletons Supports Transport of Spermatids and Residual Bodies/Phagosomes During Spermatogenesis in the Rat Testis

Germ cell transport across the seminiferous epithelium during spermatogenesis requires the intricate coordination of cell junctions, signaling proteins, and both actin- and microtubule (MT)-based cytoskeletons. Although the involvement of cytoskeletons in germ cell transport has been suggested, the precise mechanism(s) remains elusive. Based on growing evidence that actin and MT interactions underlie fundamental cellular processes, such as cell motility, it is unlikely that actin- and MT-based cytoskeletons work independently to regulate germ cell transport in the testis. Using rats treated with adjudin, a potential male contraceptive that disrupts spermatid adhesion and transport in the testis, as a study model, we show herein that actin- and MT-based cytoskeletons are both necessary for transport of spermatids and residual bodies/phagosomes across the seminiferous epithelium in adult rat testes. Analysis of intratubular expression of F-actin and tubulin revealed disruption of both actin and MT networks, concomitant with misdirected spermatids and phagosomes in rats treated with adjudin. Actin regulatory proteins, epidermal growth factor receptor pathway substrate 8 and actin-related protein 3, were mislocalized and down-regulated at the actin-rich anchoring junction between germ and Sertoli cells (apical ectoplasmic specialization) after adjudin treatment. Nonreceptor tyrosine kinase p-FAK-Tyr(407), known to regulate F-actin nucleation via actin-related protein 3, was also mislocalized and down-regulated at the apical ectoplasmic specialization, corroborating the observation of actin cytoskeleton disruption. Additionally, spatiotemporal expression of MT regulatory protein end-binding protein 1, shown to be involved in MT-actin cross talk herein, was also disrupted after adjudin treatment. In summary, spermatid/phagosome transport across the epithelium during spermatogenesis requires the coordination between actin- and MT-based cytoskeletons.

[Comparative analysis of ionizing radiation and xenobiotics influence on spermatogenic epithelium and dominant lethal mutations output in laboratory animals]

The study covered state of spermatogenic epithelium and dominant lethal mutations output in mice of BALB/c and CBA lines, subjected to total gamma-irradiation and in Wistar rats after intraperitoneal injection of potassium bichromate (K2Cr2,O7) in small and sublethal doses. The BALB/c line mice under low irradiation dose (0.25 Gy) demonstrated stimulation effect on spermatogenic epithelium, but in the CBA line mice no such effect was seen. Both mice lines under irradiation of 0.25 Gy and 1.0 Gy demonstrated increase in pathologic sperm counts and in percentage ofpreimplantation embryonal death. In rats, injection of potassium bichromate in doses of 0.028 mg/kg and 2.8 mg/kg increased number of micronuclear spermatids, larger pathologic sperm counts and percentage of postimplantation deaths. Thus, lower general embryonal deaths under radiation exposure is due to preimplantation embryonal deaths, under exposure to 6-valent chromium--is due to postimplantation losses.

Effects of prepubertal exposure to silver nanoparticles on reproductive parameters in adult male Wistar rats

The incidence of male reproductive pathologies, such as hypospadias, cryptorchidism, testicular cancer, and low sperm production in adulthood, is increasing and may be related to exposure to environmental contaminants. The silver nanoparticles (AgNP) are a new class of chemical compounds commonly used in both medical and nonmedical settings, and they affect development of spermatogonial stem cells in vitro. The aim of this study was to examine the adverse productive toxic effects of AgNPs in male Wistar rats exposed during the prepubertal period and sacrificed at postnatal day (PND) 53 and PND90. Growth was assessed by daily weighing. The progress of puberty in the rats was measured by preputial separation, while spermatogenesis was assayed by (1) measuring the sperm count in testes and epididymis and (2) examining the morphology and morphometry of seminiferous epithelium using stereological analysis. In addition, testosterone and estradiol levels were assayed by radioimmunoassay. The weight of the animals at PND90 did not change markedly, but growth was less in the group treated with AgNP at 50 μg/kg from PND34 to PND53. AgNP exposure produced a delay in puberty in both treated groups. Decreased sperm reserves in the epididymis and diminished sperm transit time were observed at PND53, while a reduction in sperm production occurred at PND90. The morphology of the seminiferous epithelium was markedly altered. Data demonstrated that prepubertal exposure to AgNP altered reproductive development in prepubertal male Wistar rats, as evidenced by impairment in spermatogenesis and a lower sperm count in adulthood.

Glyphosate impairs male offspring reproductive development by disrupting gonadotropin expression

Sexual differentiation in the brain takes place from late gestation to the early postnatal days. This is dependent on the conversion of circulating testosterone into estradiol by the enzyme aromatase. The glyphosate was shown to alter aromatase activity and decrease serum testosterone concentrations. Thus, the aim of this study was to investigate the effect of gestational maternal glyphosate exposure (50 mg/kg, NOAEL for reproductive toxicity) on the reproductive development of male offspring. Sixty-day-old male rat offspring were evaluated for sexual behavior and partner preference; serum testosterone concentrations, estradiol, FSH and LH; the mRNA and protein content of LH and FSH; sperm production and the morphology of the seminiferous epithelium; and the weight of the testes, epididymis and seminal vesicles. The growth, the weight and age at puberty of the animals were also recorded to evaluate the effect of the treatment. The most important findings were increases in sexual partner preference scores and the latency time to the first mount; testosterone and estradiol serum concentrations; the mRNA expression and protein content in the pituitary gland and the serum concentration of LH; sperm production and reserves; and the height of the germinal epithelium of seminiferous tubules. We also observed an early onset of puberty but no effect on the body growth in these animals. These results suggest that maternal exposure to glyphosate disturbed the masculinization process and promoted behavioral changes and histological and endocrine problems in reproductive parameters. These changes associated with the hypersecretion of androgens increased gonadal activity and sperm production.

Testicular toxicity of methyl thiophanate in the Italian wall lizard (Podarcis sicula): morphological and molecular evaluation

The effects of the fungicide methyl thiophanate (MT) on testis were determined in the Italian wall lizard (Podarcis sicula) using morphological and molecular analyzes. Three experimental trials were performed: an acute test using six doses, a two-week chronic test, and "ecotoxicological" exposure (3 weeks). The minimal lethal dose (LD(50)) of pure MT, reached by the acute test, was 100 mg/kg body weight. Testicular histopathology of surviving animals showed a reduced lumen and several multinucleated giant cells 24 h after injection followed by large decreases in spermatogonia (72%) and secondary spermatocytes (58%) and a loss of spermatids and sperms 7 days after. In the chronic test, a dose equivalent to 1/100 of LD(50) was injected on alternate days. Complete shutting of the lumen and a great decrease in spermatogonia (82%) were observed. In "ecotoxicological" exposure, achieved with a commercial MT compound, testis showed a decrease in primary spermatocytes (20%) and several vacuoles. An increase in germ cell apoptosis was observed in all experimental groups using TUNEL assay. A decrease in expression of androgen and estrogen receptor (AR and ER) mRNAs was seen in all experimental groups. The reduction in AR and ER mRNAs was correlated to exposure time. Indeed, in the "ecotoxicological" treatment (30 days), the decrease reached 82 and 90% for AR and ER mRNAs, respectively. These data strongly indicate that treatment with MT, damaging the seminiferous epithelium and decreasing steroid receptor expression, might render exposed lizards infertile.

The apical ectoplasmic specialization-blood-testis barrier functional axis is a novel target for male contraception

The blood-testis barrier (BTB), similar to other blood-tissue barriers, such as the blood-brain barrier and the blood-retinal barrier, is used to protect the corresponding organ from harmful substances (e.g., xenobiotics) including drugs and foreign compounds. More importantly, the BTB allows postmeiotic spermatid development to take place in an immune privileged site at the adluminal (or apical) compartment to avoid the production of antibodies against spermatid-specific antigens, many of which express transiently during spermiogenesis and spermiation. The BTB, however, also poses an obstacle in developing nonhormonal-based male contraceptives by sequestering drugs (e.g., adjudin) that exert their effects on germ cells in the adluminal compartment. The effects of these drugs include disruption of germ cell cycle progression and development, apoptosis, cell adhesion, metabolism and others. Recent studies have demonstrated that there is a functional axis that operates locally in the seminiferous epithelium to co-ordinate different cellular events across the Sertoli cell epithelium, such as spermiation and BTB restructuring during the seminiferous epithelial cycle of spermatogenesis. Components of this functional axis, such as the apical ectoplasmic specialization (apical ES, a testis-specific atypical anchoring junction type) and the BTB, in particular their constituent protein complexes, such as alpha6beta1-integrin and occludin at the apical ES and the BTB, respectively, can be the target of male contraception. In this chapter, we highlight recent advances regarding the likely mechanism of action of adjudin in this functional axis with emphasis on the use of molecular modeling technique to facilitate the design of better compounds in male contraceptive development.

Cryopreservation of adult bovine testicular tissue for spermatogonia enrichment

To develop a procedure for cryopreservation of adult bovine testis tissue, the effects of dimethyl sulphoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), and their concentrations (v/v), as well as different thawing temperatures, on the cell viability of bovine testis tissue after freezing/thawing were examined. The highest testicular cell viabilities came from the media containing DMSO (85.3 ± 1.2 percent), PG (82 ± 1.0 percent) and EG (83.4 ± 1.0 percent) at 10 percent concentration respectively. Using 10 percent DMSO gave significantly higher spermatogonia percentage (61.1 ± 1.2 percent, P < 0.001) than processing with 10 percent PG (54.3 ± 0.6 percent) or 10 percent EG (55 ± 1.8 percent) after differential plating. Thawing in water bath of 37 or 97-100 degree C also provided significantly higher viabilities (85.1 ± 1.0, 85 ± 1.0 percent, P < 0.01, respectively) and spermatogonia percentages (56.6 ± 2.0, 56.6 ± 2.6 percent, P < 0.01, respectively) than that thawing at 4C (23.4 ± 0.8 percent for total viability, 8.97 ± 1.0 percent for spermatogonia percentage). Collectively, 10 percent DMSO and thawing in 37-100 degree C water baths were appropriate for the cryopreservation of bovine testicular tissue and subsequent spermatogonia enrichment.

Drug transporters, the blood-testis barrier, and spermatogenesis

The blood-testis barrier (BTB), which is created by adjacent Sertoli cells near the basement membrane, serves as a 'gatekeeper' to prohibit harmful substances from reaching developing germ cells, most notably postmeiotic spermatids. The BTB also divides the seminiferous epithelium into the basal and adluminal (apical) compartment so that postmeiotic spermatid development, namely spermiogenesis, can take place in a specialized microenvironment in the apical compartment behind the BTB. The BTB also contributes, at least in part, to the immune privilege status of the testis, so that anti-sperm antibodies are not developed against antigens that are expressed transiently during spermatogenesis. Recent studies have shown that numerous drug transporters are expressed by Sertoli cells. However, many of these same drug transporters are also expressed by spermatogonia, spermatocytes, round spermatids, elongating spermatids, and elongated spermatids, suggesting that the developing germ cells are also able to selectively pump drugs 'in' and/or 'out' via influx or efflux pumps. We review herein the latest developments regarding the role of drug transporters in spermatogenesis. We also propose a model utilized by the testis to protect germ cell development from 'harmful' environmental toxicants and xenobiotics and/or from 'therapeutic' substances (e.g. anticancer drugs). We also discuss how drug transporters that are supposed to protect spermatogenesis can work against the testis in some instances. For example, when drugs (e.g. male contraceptives) that can perturb germ cell adhesion and/or maturation are actively pumped out of the testis or are prevented from entering the apical compartment, such as by efflux pumps.

Changes in male reproductive system and mineral metabolism induced by soy isoflavones administered to rats from prenatal life until sexual maturity

OBJECTIVE

This study aimed to determine the influence of high-dose soy isoflavones (daidzein and genistein) administered from prenatal life to sexual maturity on testosterone and estradiol levels, testicular and epididymal morphology, the number of epididymal spermatozoa, and mineral metabolism in rats.

METHODS

Pregnant Wistar rats received orally soy isoflavones, daidzein, and genistein at a dose of 200 mg/kg of body weight per day. After separating sucklings from their mothers, male rats received the same dose of isoflavones until reaching the age of sexual maturity, i.e., for 3 mo.

RESULTS

In the isoflavone-treated group, statistically significant decreased concentrations of zinc (determined using atomic absorption spectrophotometry) in blood serum and increased concentrations in bone were observed. The isoflavones induced changes in the morphology of the seminiferous epithelium of rat testes. However, there were no significant changes in the number of spermatozoa in the epididymis. The levels of estradiol in serum and cauda epididymis homogenates of rats receiving phytoestrogens were significantly higher than in the control group. No differences were observed in testosterone concentrations in the serum of treated and control rats. The testosterone levels in the homogenates of the treated rat testes were significantly lower than in the control group.

CONCLUSION

The relatively mild effects of phytoestrogen administration on the morphology of testes and epididymides and the number of epididymal spermatozoa were observed despite the high dose used. The exposure of rats to genistein and daidzein during intrauterine life until sexual maturity influenced the mineral metabolism of the organism by significant decreases of Zn concentration in serum and increased Zn concentration in bones.

Amifostine reduces the seminiferous epithelium damage in doxorubicin-treated prepubertal rats without improving the fertility status

BACKGROUND

Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out.

METHODS

Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). "Standard One Way Anova" parametric and "Anova on Ranks" non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05.

RESULTS

The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration.

CONCLUSIONS

These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models.

Melatonin prevents damage elicited by the organophosphorous pesticide diazinon on the mouse testis

Organophosphates like O,O-diethyl O-2-isopropyl-6-methyl pyrimidinyl-4-g-1-phosphorothioate (diazinon) are pesticides used worldwide, which can affect both animals and man even after a single exposure. Whereas their toxicity is due to acetylcholinesterase inhibition, their secondary toxic effects have been related to free oxygen radicals. This study evaluates the effects of a single dose of diazinon and melatonin-a powerful antioxidant-on plasmatic acetylcholinesterase activity and testis histopathology in adult mice 1 and 32 days post-treatment. Diazinon diminished the plasma acetylcholinesterase activity on day 1 post-treatment, although testosterone levels remained unaffected. Morphometrical analysis showed a decrease in seminiferous epithelium height (days 1 and 32), whereas an increase in testicular superoxide dismutase (SOD) activity was detected (day 32). Melatonin pretreatment prevented every alteration induced by diazinon, except the diminution of acetylcholinesterase plasmatic activity. Testicular damage might be due to elevated concentrations of free oxygen radicals released upon diazinon exposure, inducing alterations in the DNA and promoting local apoptosis; however, antioxidant pretreatment with melatonin prevents or diminishes this damage.

Spermatogenesis following discontinuation of calcium channel blocker amlodipine in rats

BACKGROUND

The calcium channel blockers are commonly associated with male infertility. Long-term administration of such drugs has been shown to suppress spermatogenesis. The present study was designed to determine the effects of cessation of calcium channel blocker (amlodipine) medication on spermatogenesis.

METHODS

The study was carried out in the Department of Physiology, in collaboration with Department of Pathology, Army Medical College, and National Institute of Health, Islamabad from April 2007 to March 2008. Thirty male rats were divided into two groups A and B each containing 15 rats. Group A rats were given distilled water (vehicle) whereas group B rats were given amlodipine by oral gavage for 50 days. After 50 days, amlodipine/distilled water was withdrawn. The rats were left for recovery to take place for another 50 days of drug withdrawal period. Testes were removed in all the rats and sectioned. The sections were stained with haematoxylin and eosin and examined microscopically. Results were analyzed using SPSS version 13.

RESULTS

Fifty days after drug withdrawal, there were statistically insignificant differences in mean tubular diameter and height of germinal epithelium between amlodipine treated and vehicle treated groups.

CONCLUSION

Spermatogenesis in amlodipine treated rats does not differ significantly from spermatogenesis in vehicle treated rats after 50 days of drug withdrawal period.

Histological changes in seminiferous epithelium in testis of male mice induced by injection of lipopolysaccharide (LPS)

LPS induces an inflammatory state which kmitates septic shock and which involves also an organ which is immunologically advantageous, namely testicle. Within an area of a gonad, this manifests itself by histological changes in the structure of germinal epithelium. The blockages of cell divisions lead also to disorders in the proportions of cells in particular stages of spermatogenesis, degeneration of germinal epithelium and the decrease of the number of spermatozoa in the lumen of seminiferous tubules. Maximal changes are observed on the 15th day of inflammatory state and they are reversible with the process of the animals' restoration to health. The number of macrophages rises quickly in Leydig's glands and it remains constant till the 28th day after the administration of LPS.

Amifostine protective effect on cisplatin-treated rat testis

Cisplatin is a potent drug used in clinical oncology but causes spermatogenesis damage. Amifostine is a drug used against toxicity caused by ionizing irradiation and chemotherapeutic drugs. Since cisplatin provokes fertility and induces germ cell apoptosis and necrosis, we proposed to evaluate the amifostine cytoprotective action on testes of cisplatin-treated rats. Thirty-day-old prepubertal Wistar rats received a single cisplatin dose of 5 mg/kg and were killed after 3, 6, and 12 hr. The hematoxylin-eosin stained testicular sections were submitted to histological, morphometric, and stereological analysis. The terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling (TUNEL) method was used to label apoptotic cells. TUNEL-positive and TUNEL-negative germ cells with abnormal nuclear morphology (ANM) were scored. Significant alterations of greater part of the parameters occurred in the cisplatin-treated group (CE) compared to the group that received amifostine before the cisplatin-treatment (ACE); however, testicular weight and volume did not vary between these groups. Tubular diameter was reduced in CE in comparison to ACE rats, while interstitial tissue and lymphatic space volume and volume density were significantly higher in CE rats; interstitial testicular edema probably occurred in cisplatin-treated rats. CE rats showed important histological alterations, which were more accentuated than in ACE rats. The numerical densities of apoptotic germ cells and TUNEL-negative cells with ANM were lower in ACE than in CE rats. In conclusion, the amifostine previously administered to prepubertal rats reduced the testicular damage caused by cisplatin. We conclude that amifostine partially protected the rat seminiferous epithelium against cisplatin toxicity.

Mechanism of action of l-CDB-4022, a potential nonhormonal male contraceptive, in the seminiferous epithelium of the rat testis

The present study was conducted to elucidate the possible molecular mechanisms involved in the antispermatogenic activity of l-CDB-4022, an indenopyridine. In this study 45-d-old male Sprague-Dawley rats were treated with a single oral dose of l-CDB-4022 (2.5 mg/kg) or vehicle, and blood and testes were collected at various time points. The rate of body weight gain was not affected, but a significant loss of testes weight was induced by l-CDB-4022. Serum hormones were assayed using specific RIAs or ELISAs, and testicular protein and RNA were analyzed by Western blotting and RT-PCR, respectively. There was a significant decrease in inhibin B and concomitant increase in FSH in serum from l-CDB-4022-treated rats, but serum levels of activin A, testosterone, and LH were unchanged. Western analysis of testicular lysates from l-CDB-4022-treated rats exhibited phosphorylation of ERK1/2 at 4 h and later time points. Loss of nectin/afadin complex occurred at 48 h, but there was an increase in levels of integrin-beta1, N-cadherin, alpha-catenin, and beta-catenin protein at 24 h and later time points. Increase in expression of Fas ligand and Fas receptor was detected 8 and 24 h after l-CDB-4022 treatment. The ratio of the membrane to soluble form of stem cell factor mRNA was decreased. Immunohistochemical analysis of testicular sections indicated a dramatic disruption of the Sertoli cell microtubule network in l-CDB-4022-treated rats. Collectively, these results suggest that l-CDB-4022 activates the MAPK pathway, reduces expression of prosurvival factors such as the membrane form of stem cell factor, alters expression of Sertoli-germ cell adherens junction proteins, disrupts Sertoli cell microtubule structure, and induces the proapoptotic factor, Fas, culminating in germ cell loss from the seminiferous epithelium.

Testicular development of Zebu bulls after chronic treatment with a gonadotropin-releasing hormone agonist

The objective was to compare testis characteristics of Zebu bulls treated with the GnRH agonist, deslorelin, at different times and for different durations during their development. An additional objective was to determine the usefulness of a stain for the transcription factor GATA-binding protein 4 (GATA-4) as a specific marker for Sertoli cell nuclei in cattle. Bulls (54) were allocated to nine groups (n = 6) and received s.c. deslorelin implants as follows: G1 = from birth to 3 mo of age; G2 = from 3 to 6 mo; G3 = from 6 to 9 mo; G4 = from 9 to 12 mo; G5 = from birth to 15 mo; G6 = from 3 to 15 mo; G7 = from 6 to 15 mo; G8 = from 12 to 15 mo; and G9 (control) = no implant. Bulls were castrated at 19 mo of age. Paraffin sections (10 microm) were subjected to quantitative morphometry and GATA-4 immunohistochemistry. At castration, all bulls in the control group (6/6) had attained puberty (scrotal circumference > or = 28 cm), whereas a smaller proportion (P < 0.05) had reached puberty in G2 (2/5) and G6 (1/6). Bulls in G2 and G6 also had a lesser (P < 0.05) testis weight compared with the control group. Total volume of seminiferous epithelium and total daily sperm production in G2 and G6 were only half that observed in the control group. Spermatids were observed in less than 50% of seminiferous tubules in G2, G6, and G7 compared with 82% in the control group (P < 0.05). Staining for GATA-4 was specific for and abundant in the Sertoli cell nucleus in both pre- and postpubertal bulls, and no other cell nucleus inside the seminiferous tubule was positive for GATA-4. Total number of Sertoli cells was not affected by treatment (P = 0.45), but nuclear volume was smaller in G2 and G6 (P < 0.05) compared with the control group. In conclusion, treatment of Zebu bulls with deslorelin had no apparent beneficial effect on testis development and delayed puberty when treatment was initiated at 3 mo of age. Staining for GATA-4 was a useful method for identifying and quantifying Sertoli cell nuclei in both pre- and postpubertal bulls.

Aflatoxin treatment brings about generation of multinucleate giant spermatids (symplasts) through opening of cytoplasmic bridges: Light and transmission electron microscopic study in Swiss mouse

Aflatoxins are dietary mycotoxins, which are a health hazard. Sub-symptomatic exposure to aflatoxins is known to produce male reproductive toxic effects with several manifestations. With a view to find if aflatoxins would produce multinucleate giant cells or symplasts in the seminiferous epithelium, we treated male Swiss mice with aflatoxin B(1) for 35 days and subjected the testis to light and transmission electron microscopic analysis. We found abundant symplastic spermatids in the seminiferous epithelium of treated mice. The origin of these cells was traced to opening of cytoplamic bridges. Due to widening of cytoplasmic bridge, the cytoplasm of spermatid(s) in a clone entered a cytoplasm-rich spermatid, followed by the nucleus/nuclei. Subsequently, the bridge(s) collapsed resulting in spherical symplasts. The study, in addition to revealing yet another manifestation of aflatoxin-induced disruption of spermatogenesis, also provides first direct evidence for opening of cytoplasmic bridges as the mechanism underlying origin of spermatid symplasts.

Ultrastructure of the seminiferous epithelium of ethyl methanesulphonate-treated mouse

Ethyl methanesulphonate (EMS) is a mutagenic alkylating agent that induces marked elevations of sperm abnormalities in mice. In this paper, we report the ultrastructural findings on the morphology of the seminiferous epithelium of mice resulting from EMS administration. Eight- to twelve-weeks-old male mice were injected intraperitoneally with EMS at 200 mg kg(-1) body weight daily for five consecutive days. Analysis of smears of epididymis and semi-thin sections of testes revealed that the more suitable specimens for the ultrastructural analysis were tissues of mice killed at the third week, following EMS administration. At this time, the spermatid was the damaged cell type. Abnormalities were mainly observed in the morphology of the nucleus, the acrosome, chromatin distribution and in the arrangement of the cytoplasmic microtubules, and binucleated spermatids were also observed. EMS has the capacity to penetrate the blood-testis barrier, and thus it can damage post-meiotic spermatogenic cells. However, morphological abnormalities could be the consequence of damage exerted on the differentiated spermatogonia stage, the most sensitive spermatogenic cell to the action of chemical agents or drugs. Our findings contribute to elucidate the action mechanism of the damage exerted by EMS administration on the germinal male cells.

Formaldehyde exposure induces histopathological and morphometric changes in the rat testis

Formaldehyde is a chemical which is traditionally used for fixing cadavers and routine histopathology techniques. It is vaporised during the dissection and practical study of a cadaver. Previous studies have shown that this vapour may cause clinical symptoms such as throat, eye, skin and nasal irritation. This study was designed to determine the histopathology and morphometrics of the rat testis when all the experimental animals were exposed to formaldehyde for 18 weeks. The study was performed in 2004 on 28 albino Wistar rats of 6-7 postnatal weeks. The rats were divided into three case groups (E1: 4 h/d, 4 d/w; E2: 2 h/d, 4 d/w; E3: 2 h/d, 2 d/w) and one control group. The testes specimens were sectioned at 5 microm and stained with the haematoxylin and eosin staining technique for histological and morphometrical studies. We found a severe decrease in germ cells associated with spermatogenesis arrest in the E1 group. A decrease in germ cells and a thickening of the basal membrane of the seminiferous tubules were seen in E2. Displacement of Sertoli and germinal cells were also found in the E3 group. The mean seminiferous tubular diameter and seminiferous epithelial height in the experimental groups were decreased in comparison with the control group and the differences were statistically significant (p < 0.05). The findings of this study revealed that chronic formaldehyde exposure can cause histopathological and morphometric changes to the seminiferous epithelium in rats and that these changes depend on the duration of the formaldehyde exposure.

Cycle Length of Spermatogenesis in Shrews (Mammalia: Soricidae) with High and Low Metabolic Rates and Different Mating Systems1

The aim of the present study was to establish and compare the durations of the seminiferous epithelium cycles of the common shrew Sorex araneus, which is characterized by a high metabolic rate and multiple paternity, and the greater white-toothed shrew Crocidura russula, which is characterized by a low metabolic rate and a monogamous mating system. Twelve S. araneus males and fifteen C. russula males were injected intraperitoneally with 5-bromodeoxyuridine, and the testes were collected. For cycle length determinations, we applied the classical method of estimation and linear regression as a new method. With regard to variance, and even with a relatively small sample size, the new method seems to be more precise. In addition, the regression method allows the inference of information for every animal tested, enabling comparisons of different factors with cycle lengths. Our results show that not only increased testis size leads to increased sperm production, but it also reduces the duration of spermatogenesis. The calculated cycle lengths were 8.35 days for S. araneus and 12.12 days for C. russula. The data obtained in the present study provide the basis for future investigations into the effects of metabolic rate and mating systems on the speed of spermatogenesis.

Cobalt-induced alterations in hamster testes in vivo

The purpose of this study was to assess the effects of cobalt on the testicular structure of adult golden hamsters. Hamsters in group A received cobalt (CoCl2) in single intraperitoneal dose 20 mg/kg, in group B 10 mg/kg and in group C 5 mg CoCl2/kg body weight and were killed fourty eight hours after cobalt administration. Afer a preparation of histological samples the results were compared with control. After a cobalt administration dilatation of blood capillaries in interstitium, undulation of basal membrane and occurrence of empty spaces in seminiferous epithelium was detected. Morphometric analysis showed that in all cobalt-treated groups the relative volume of seminiferous epithelium was significantly decreased. In the relative volume of interstitium a significant increase was found between control group and experimental groups. After cobalt administration we have found linear non-significant decrease. Evaluation of diameter seminiferous tubules found increase of this parameter in the all experimental group in comparison with control. Height of seminiferous epithelium was relatively constant and in all groups but the difference between control and group A was significant (P < 0.05). Analysis of the lumen diameter of seminiferous tubules detected significantly increase mainly group B. Evaluation of the number of cell nuclei per a constant area detected an increase of this parameter in experimental group. Results of this study report a negative effect of cobalt on structure and function of testes.

Diesel Exhaust Particle Toxicity on Spermatogenesis in the Mouse is Aryl Hydrocarbon Receptor Dependent

Diesel exhaust particles (DEPs) are particulate matter from diesel exhaust containing many toxic compounds, such as polyaromatic hydrocarbons (PAHs). Some toxicities of PAH are considered to express via aryl hydrocarbon receptor (AhR). We hypothesized that the male reproductive toxicity of DEPs may depend on PAHs. BALB/c male mice received 24.7, 74.0 or 220 microg/mouse DEP suspension or vehicle injected into the dorsal subcutaneous layer 10 times during 5 weeks. The mice were euthanized, and blood and organs were collected 2 weeks after the last treatment. The epididymis weights, relative epididymis weights per body weight and daily sperm productions and viabilities of the 74.0 and 220 microg/mouse DEP-treated groups decreased significantly compared with those of the vehicle group. The total incidence of sperm abnormalities in the 74.0 and 220 microg/mouse DEP-treated groups increased significantly compared with the vehicle group. The seminiferous epithelium area ratios of the 74.0 and 220 microg/mouse DEP-treated groups were significantly higher compared with the vehicle and 24.6 microg/mouse DEP-treated groups. The ratios of seminiferous tubules with elongated-type spermatids in the 74.0 and 220 microg/mouse DEP-treated groups were significantly decreased compared with the vehicle group. The testosterone level and hepatic ethoxyresorufin-O-deethylase (EROD) activity as an indirect index of AhR activity in the 74.0 microg/mouse DEP-treated group were significantly increased compared with those of the vehicle group. These results clearly demonstrated that DEPs suppress testicular function, especially spermatogenesis and sperm motility. These effects may be AhR dependent.

Effects of lithium carbonate on rat seminiferous tubules: an ultrastructural study

Lithium salts are commonly used for treatment of bipolar disorder but prolonged treatment with therapeutic doses induces substantial toxic effects. In the present study we examined the effects of lithium carbonate on the ultrastructure of rat seminiferous tubules. Rats were exposed to lithium carbonate at doses of 35 mg/kg/day for 21 days. After lithium treatment, the tunica propria widened and folded together with convolutions of the basement membrane, myoid cells and lymphatic endothelium. In the seminiferous epithelium loss of germ cell attachment and appearance of expanded intercellular spaces between spermatogenic cells were observed. Early stages of spermatogenic cells showed nuclear protrusions or swellings because of an extensive enlargement of the outer nuclear membrane. Round spermatids exhibited abnormally shaped acrosomes and dilation of the subacrosomal space. Many abnormal, degenerated late spermatids with random orientation were seen towards the basal and adluminal compartments of the seminiferous epithelium. In addition, spermatids exhibited alteration in F-actin bundle ectoplasmic specialization and contained many mitochondria-associated granular bodies.

Adjudin-mediated junction restructuring in the seminiferous epithelium leads to displacement of soluble guanylate cyclase from adherens junctions

A plethora of evidence supports the role of cyclic nucleotides in junction restructuring. For instance, studies have shown cGMP to be a key regulator of junction assembly and disassembly in different in vitro and in vivo systems. In this study, we examine the role of soluble guanylate cyclase (sGC) in junction restructuring in the seminiferous epithelium of the rat testis. First, the interaction of soluble guanylate cyclase beta1 (sGCbeta1; sGC is a heterodimer comprised of an alpha and a beta subunit) with proteins that constitute adherens and tight junctions in the testis was demonstrated. By immunoprecipitation, sGCbeta1 was found to associate with occludin, JAM-A, and ZO-1, as well as with cadherin, catenin, nectin, afadin, ponsin, and espin, suggestive of its role in cell junction dynamics. These results were corroborated in part by immunohistochemistry experiments, which revealed that the localization of sGCbeta1 was largely restricted to the site of the apical and basal ectoplasmic specialization. Next, the role of sGC in junction dynamics was addressed by using an in vivo model of junction restructuring. Administration of Adjudin--a chemical entity known to specifically perturb adhesion between Sertoli and germ cells (i.e., round and elongate(ing) spermatids and most spermatocytes)--resulted in a approximately 1.5-fold increase in sGCbeta1, coinciding with the loss of germ cells from the epithelium. More importantly, the ability of sGCbeta1 to associate with cadherin increased approximately three-fold during Adjudin-mediated restructuring of Sertoli-germ cell junctions, whereas its interaction with tight junction proteins (i.e., occludin and ZO-1) decreased. Taken collectively, these results suggest that sGC participates in the remodeling of cell junctions during spermatogenesis.

Blockage of testicular connexins induced apoptosis in rat seminiferous epithelium

Spermatogenesis, a tightly regulated developmental process of male germ cells in testis, is associated with temporal and spatial expression of gap junction proteins, such as the connexin family members. Perturbation of their expressions may lead to spermatogenic arrest as manifested by disruption of cell-cell interaction. To explore the role(s) of connexins during spermatogenesis, we utilized the small peptide antagonistic approach to specifically deplete connexin 31, connexin 33, and pan-connexin. Three connexin peptides corresponding to the extracellular binding domain of connexin 31 and connexin 33 and to the extracellular conserved domain of connexins were designed and synthesized commercially. Peptides (at single dosage of 0.5, 1, or 2 mg per animal) were injected into rat testes and testes were collected on day 0, 1, 3, 5, 10, 15, and 30 after microinjection. In situ TUNEL assay demonstrated the induction of apoptosis in the testes after pan-connexin peptide treatment in a dose-dependent manner from day 3 and onward. Unlike the pan-connexin peptide, connexin 31 and connexin 33 peptides appeared to have little effect on inducing apoptosis and germ cell loss. CD45 staining also detected the occasional presence of infiltrating lymphocytes in the seminiferous tubules. Accompanied with the apoptotic events, two apoptotic markers, NF-kappaB and caspase 3, demonstrated a general up-regulation in their expressions. In adjacent testis sections, eliminations of connexin 31, 32, and 43 were observed. However, an induction of connexin 33 expression was detected. This suggests the versatility and functional diversity of connexins in the testis. The expression of ZO-1, the only known adaptor of connexins in the testis, was reduced and remained in a low level in the seminiferous epithelium. As such, the alterations of connexins in seminiferous epithelium may induce apoptotic signaling in the testis via the caspase 3 and the NF-kappaB pathway. This demonstrates the significant role of testicular connexins to maintain the survival of germ cells by regulating inter-cellular communications among germ cells and adjacent supporting cells during spermatogenesis. In addition, the inter-relationship between connexins and other junction proteins and associated signaling protein were investigated. After pan-connexin peptide treatment, a dys-localization of N-cadherin, an adherens junction protein, and diminution of occludin, a tight junction protein, level were detected. In addition, inductions of junction regulatory protein, cathepsin L, was observed during the course of peptide-mediated germ cell loss in the testes. In summary, pan-connexin peptide treatment triggered apoptosis and germ cell loss in the testes. This event influenced the localization and expression of different junction proteins and junction-associated protein in the testes.

Sertoli cell function in albino rats treated with etoposide during prepubertal phase

Sertoli cell plays a key role in spermatogenesis. Many studies refer that this cell is not harmed by the majority of anticancer treatments known to cause damage to the testis. However, in the previous study we observed that etoposide, an efficient chemotherapeutic drug, provokes an increase in numerical density of the Sertoli cells. This phenomenon suggests that this cell was harmed by etoposide. Thus, we decided to investigate a possible direct action of etoposide on Sertoli cells analyzing the function of this cell and relating it with the integrity and damage of the seminiferous epithelium. Prepubertal albino rats received 5 mg/kg of etoposide for eight consecutive days and were sacrificed in different ages. The control groups received 0.9% saline solution. The testes were fixed in Bouin's liquid for transferrin immunolabeling and testicular labeled tissue volume density measurement. Except for the younger rats, all the etoposide-treated rats showed diminution of transferrin immunolabeling in the seminiferous epithelium, and consequently, of total labeled testicular tissue volume density. We concluded that the diminution of transferrin labeling in the seminiferous epithelium was not associated with germ cell absence such as commonly reported. The results suggest etoposide impairs Sertoli cell function.

Estrogenic induction of spermatogenesis in the hypogonadal (hpg) mouse: role of androgens

Testicular development is arrested in the hypogonadal (hpg) mouse due to a congenital deficiency of hypothalamic gonadotropin-releasing hormone synthesis. Previous studies have demonstrated that chronic treatment of these mice with estradiol induces testicular maturation and qualitatively normal spermatogenesis, but it is not known whether these are direct effects via estrogen receptors expressed in the testis, or indirect actions via the pituitary gland. The aim of the current studies was to determine whether the actions of estradiol require the presence of androgens. Sensitive assays revealed that chronic estradiol treatment produced time-dependent increases in pituitary FSH production but no increases in pituitary LH or testicular testosterone content could be detected. As a functional test of androgen dependence, hpg mice were treated for 70 days with estradiol plus Casodex (bicalutamide), an androgen receptor antagonist. Casodex treatment markedly attenuated both the estradiol-induced increase in testicular weight and the proliferation of the seminiferous epithelium, as revealed by morphometric analysis. However, it did not affect the estradiol-induced increase in pituitary FSH content, nor did it affect estradiol-induced increases in the weight of the seminal vesicles and epididymides. We conclude that increased FSH production is not sufficient to explain the increase in testicular development induced by estradiol in hpg mice; there is a requirement for functional androgen receptors for induction of testicular growth.

Seminiferous epithelium of rats with food restriction and carbon tetrachloride-induced cirrhosis

OBJECTIVE

Analyze the changes in the seminiferous epithelium in rats with carbon tetrachloride-induced cirrhosis (CCl4).

MATERIALS AND METHODS

Forty-eight male Wistar rats aged 45-50 days, weighing 150-180 grams were used. Twenty-two rats underwent CCl4-induced cirrhosis with CCl4 0.25 mL/Kg weekly intragastrically once a week, during 10 weeks. Additionally, they had a 44% food restriction diet (Group 1). The control group was divided in two subgroups: 13 rats had a 44% food restriction diet and no CCl4 (Group 2) and 10 rats were not submitted to CCl4 or food restriction (Group 3). After 10 weeks, the rats were sacrificed and liver sections were collected for histological analysis. The testicular analysis was carried out to evaluate the frequency of tubules in stages VIII and XIV.

RESULTS

The mean rates of stage VIII in animals with food restriction plus CCl4-induced cirrhosis and food restriction without CCl4 were significantly different from animals without either food restriction or CCl4 (18.1 +/- 5.5%, 20.5 +/- 2.5% and 13.4 +/- 3.5%, respectively, p = 0.002). The mean rate of stage VIII in rats with cirrhosis was not significantly different from rats without cirrhosis (18.1 +/- 5.5% and 17.4 +/- 4.6% respectively). The mean frequency of stage XIV in rats with cirrhosis was significantly greater than rats without cirrhosis (4.7 +/- 2.3% and 6.8 +/- 1.9% respectively, p = 0.027).

CONCLUSION

Animals with CCl4-induced cirrhosis and food restriction have shown alterations in spermatogenic cycle that were not seen in rats without CCl4-induced cirrhosis and food restriction.

Immunohistochemical study of serum albumin in normal and cadmium-treated mouse testis organs by "in vivo cryotechnique"

The in vivo injection of cadmium (Cd) was reported to induce blood-testis barrier disruption, and assumed to be an experimental model to examine junctional structures in seminiferous tubules. The purpose of this study is to investigate time-dependent changes of albumin permeability in the normal or Cd-treated mouse testis by our "in vivo cryotechnique" with immunohistochemistry, reflecting tight junctional (TJ) barriers of Sertoli cells. The albumin in the seminiferous tubules was firstly immobilized by the cryotechnique, in which normal blood circulation was always kept. The cryofixed testicular tissues were then processed for freeze-substitution, and embedded in the paraffin wax. Serial sections were immunostained by anti-mouse albumin antibody with peroxidase immunostaining, and also stained with hematoxylin-eosine (HE) for morphological observation. In normal seminiferous tubules, the immunoreaction products were localized around peritubular myoid cells and between Leydig cells, as well as in blood vessels. They were also localized as arch-like patterns around some spermatogonia in basal compartments of seminiferous tubules. Twenty-four and 48 hrs after Cd-treatment, some enlarged spaces and vesicular formations in the seminiferous epithelium were observed on the HE-stained sections. The albumin immunolocalization was detected not only in the basal compartments, but also in the adluminal compartments between Sertoli cells and germ cells. Thus, the structural disruptions of inter-Sertoli TJ barriers could be clearly demonstrated by the "in vivo cryotechnique".

Morphometric and stereological assessment of the effects of long-term administration of quinine on the morphology of rat testis

BACKGROUND AND OBJECTIVES

Quinine (QU) has been used worldwide in the suppression and treatment of malaria for more than 350 years. The aim of this study was to determine the long-term morphological response of the testis to long-term administration of QU using stereological parameters.

MATERIALS AND METHODS

64 adult male Sprague-Dawley rats weighing 180-200g were used. The animals were randomly divided into 8 groups of 8 rats each. Every experimental animal had intramuscular QU at a dose of 10mg/kg body weight per day (5 times in a week, with the exception of group 1 animals). Group 1 rats had QU for 1 week (7 days consecutively) and were sacrificed on the last day of injection. Groups 2 and 3 rats had QU for 4 and 6 weeks and were sacrificed at the end of the 4th and 6th week respectively. Group 4, 5, 6 and 7 rats had QU for 8 weeks and were sacrificed at the end of week 8, 12, 16 and 20 respectively. Group 8 animals constituted the controls and had equal volume of distilled water intramuscularly for 8 weeks. All sacrifices were by decapitation. The testes were carefully dissected out, their volumes measured, weighed and histological sections prepared. Morphometric assessment was carried out using the diameter, cross-sectional area, number of profiles per unit area, numerical density and volume density of the seminiferous tubules and the relative and absolute volume of the seminiferous epithelium, stroma and lumen of tubules.

RESULTS

The results showed that there was a general destruction of cells of the seminiferous tubules and the testicular interstitium that persisted even after the discontinuation of QU and to the end of our experiment that lasted 20 weeks.

CONCLUSION

We conclude that QU has deleterious effect on the seminiferous tubules of Sprague-Dawley rats, though the mechanism of damage is unclear.

Impairment of spermatogenesis and enhancement of testicular germ cell apoptosis induced by exogenous all-Trans-retinoic acid in adult lizardPodarcis sicula

In mammals, retinoic acid is involved in the regulation of testicular function by interaction with two families of nuclear receptors, retinoic acid receptor (RAR) and retinoid X receptor (RXR). Among RAR isoforms, the testicular cells of the lizard were found to express only RARalpha (3.7 kb) and RARbeta (3.4 kb) mRNAs, as reported here. In this study, the effects of exogenous all-trans-retinoic acid (atRA) on spermatogenesis of a non-mammalian seasonal reproducer were investigated. Daily intraperitoneal injections of atRA or atRA plus testosterone (atRA+T) were given for 2 weeks to adult males of the lizard Podarcis sicula. In animals treated with atRA, the seminiferous tubules were markedly reduced in cross-area. The seminiferous epithelium collapse was responsible for a sensible reduction in the number of germ cells and disruption in normal epithelial organization. In comparison, in atRA+T-treated lizards the loss of germinal cells was significantly less. The loss of germ cells observed in both experimental groups results from an induction of apoptotic process, as revealed by TUNEL analysis. Although low in number, apoptotic germ cells were also observed in the control groups (saline- and T-treated lizard), where the main germ cells undergoing apoptosis are primary spermatocytes (most frequently) and some spermatogonia. In conclusion, it is shown here that retinoic acid has deleterious effects on lizard spermatogenesis, causing a severe depletion of seminiferous epithelium, probably via induction of apoptotic processes. These effects are not completely inhibited by simultaneous administration of testosterone, although this hormone, once injected, is able to stimulate spermatogenesis and protect germinal cells from apoptotic cell death.

Long-term effects of lonidamine on mouse testes

Lonidamine (LND) [1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid] is a well-known antispermatogenic drug. The aim of this study was to identify its possible long-term sequelae on the reproductive system of mice as compared with rats, where most data have been obtained until now. Sexually mature CD1 male mice were administered a single dose of LND (200 mg/kg bw by gavage) and killed 24 and 48 h, 6 days and 2, 4 and 8 weeks after the treatment. Testes were collected, weighed and (1) fixed in Bouin's solution for histological analysis or (2) reduced to monocellular suspensions and ethanol fixed to undergo flow cytometry (FCM) DNA content analysis. No effect on body weight and/or food consumption was observed in the treated group in comparison with the control group. Testicular weight was significantly reduced 24 h after the treatment. Reduced seminiferous epithelium with a progressive lack of intercellular cohesion and marked depletion of spermatids, infiltration of granulocytes, desquamation into the tubular lumen and increased intertubular spaces were present by 24 h after the treatment and persisted to a marked degree at 48 h, 6 days and 2 and 4 weeks up to a marked degeneration of tubular structures with absence of spermatogenesis. The same effects, albeit with a moderate severity, were still present 8 weeks after the treatment. As also detected by FCM, primary spermatocytes appeared to be the main cellular target. Sertoli and Leydig cells were remarkably spared. The histological findings are consistent with those previously observed in rats and point out that testicular damage may persist for several weeks after a single-dose administration. Findings are discussed in comparison with testicular toxicity elicited by other xenobiotics.

Serotoninergic system blockage in the prepubertal rat inhibits spermatogenesis development

The stimulatory and inhibitory role of serotonin in gonadotropin secretion and in the onset of puberty in the male rat has been previously described, but its role in the establishment of spermatogenesis is not known. The aim of this study was to investigate the effects of serotoninergic inhibition by p-chloroamphetamine (pCA) on the prepubertal-to-adult stage of the rat reproductive system. Hypothalamic serotonin, gonadotropins and sex steroid hormone concentrations were measured, and a histopathological analysis of seminiferous epithelium was carried out on animals treated with pCA from day 30 and killed at 45 or 65 days of age. The pCA treatment significantly reduced the hypothalamic levels of serotonin and its metabolite (5-hydroxyindole-3-acetic acid). This inhibition did not affect the sex steroid hormone or LH concentrations, but rather it induced an increase in FSH concentration in animals of both ages. Spermatogenesis was impaired by pCA treatment. Disruption of seminiferous epithelium and the death of numerous germ cells were observed. Sperm produced by pCA-treated animals was of poor quality and appeared in small quantities. Apparently, serotonin depletion did not affect communication between the hypothalamus and the pituitary, but the FSH increase could have been related to alterations in the seminiferous epithelium effects. The seminiferous epithelium cycle was altered in rats killed at both 45 and 65 days of age, because at each age of killing the distribution of spermatogenesis stages was different. Germ cell apoptosis did not appear to be related to changes in the FSH concentrations, but other factors produced during spermatogenesis could have been involved in this induction. This study showed that serotonin was necessary for the development of normal spermatogenesis in prepubertal rats.

Effects of a low dose of bentazon on spermatogenesis of mice exposed during foetal, postnatal and adult life

Bentazon is a herbicide used to control many broadleaf weeds and sedges. Its use has improved rice production in paddy fields in Northern Italy, but as a negative consequence it is found in groundwater, the major source of drinking water. To determine whether low doses of bentazon affect spermatogenesis, it was dissolved in water at the concentration of 30 microg/L. Bentazon was administered through drinking water to: (1) adult mice for 100 days and (2) mice exposed in utero, during lactation and for 100 days after birth. The histopathological analysis of testes of treated animals showed that the frequency of defective tubules was comparable to that found in control groups. The cell associations of the 12 stages of the seminiferous epithelium were correct as well as the architecture of the epithelium. The spermatocytes/spermatids ratio was the same as in controls. However, the frequency of stages VII, IX and XII of the cycle of the seminiferous epithelium of adult mice and of stages I, III and VII of mice exposed in utero and for 100 days after birth was different when compared to that of control mice. Sperm number and morphology were not affected by the treatment. The potential genotoxic effects were evaluated on spermatozoa (Comet assay), in pachytene spermatocytes (analysis of the synaptonemal complex) and in bone marrow cells (frequency of micronuclei). None of these analyses evidenced genotoxic effects of bentazon. Although our results show that the administration of a low dose of bentazon does not impair spermatogenesis, we found alterations of the frequency of some stages of the cycle of the seminiferous epithelium in both experimental groups.

Attenuation of quinine-induced testicular toxicity by ascorbic acid in rat: a stereological approach

Quinine (QU), an alkaloid derived from the cinchona bark is presently the mainstay of treatment for severe malaria and nocturnal leg cramps. We have recently demonstrated that QU is toxic to testicular gonocytes and interstitial endocrinocytes. This present study sought to determine whether co-administration of ascorbic acid (AA) with QU will modify the deleterious effects of QU on the testes of Sprague-Dawley rats. 50 male Sprague-Dawley rats weighing 160-180g were used for the experiments. The animals were randomly divided into 5 groups of 10 rats each and were variously administered QU for 7 days, QU for 8 weeks, QU plus AA for 7 days, QU plus AA for 8 weeks and distilled water. They were all sacrificed on the 56th day. Histological slides of the testes were prepared and morphometric parameters that included diameter and cross-sectional area of the seminiferous tubules, number of profiles of seminiferous tubules per unit area of testis and numerical density of the seminiferous tubules, volume density and absolute volume of testicular components were determined using a systematic random scheme. Our results showed that the cytoarchitecture of seminiferous tubules of rats treated with QU only was grossly distorted, while that of rats that had both QU and AA was not significantly different from that of the controls. The testicular volume; diameter and cross-sectional area of seminiferous tubules; and the relative and absolute volume of seminiferous epithelium of QU-treated rats were significantly (P < 0.05) reduced, while those of QU plus AA-treated Ones were not significantly different from those of the controls. In contrast, the numerical density of the tubules were significantly (P < 0.05) increased in rats administered QU only, while it was not significantly different in the QU plus AA-treated and control rats. We conclude that co-administration of AA with QU could play an important role in the modulation of QU-induced testicular damage.

Short-term effects of carbendazim on the gross and microscopic features of the testes of Japanese quails (Coturnix coturnix japonica)

Carbendazim, a metabolite of benomyl which is widely used as a fungicide, has been found to cause testicular and epididymal damage in laboratory rats, mice and hamsters. No studies of the effects of this chemical on the reproductive organs of birds have been reported previously. This report is that of an investigation on the response of the testis of the Japanese quail to experimental administration of this chemical in sexually mature and active birds. A single dose (400 mg/kg body weight) of carbendazim was administered orally to 20 quails that were sacrificed thereafter at 5 h, 3, 8 and 13 days post-exposure, at five birds spatio-temporally. Five birds acted as control. Testis weights and seminiferous tubular diameter as well as epithelial height decreased significantly from 8 day post-exposure. Epithelial histology was remarkably disrupted, and cessation of spermatogenesis occurred at 13 day post-administration of the chemical. Degenerative changes were uniform in each testis, and not patchy or multi-focal, as previously reported in the rat. The observed histological changes in the testis, due to carbendazim, were capable of causing prolonged infertility in exposed birds.

Vanadium induced ultrastructural changes and apoptosis in male germ cells

Vanadium is a transition metal that is emitted to the atmosphere during combustion of fossil fuels. In the environment, vanadium occurs in the (V) oxidized form, but in the body it is found exclusively in the (IV) oxidized form. Vanadium tetraoxide is an inorganic chemical species in the (IV) oxidized form that has been shown to induce toxic effects in vitro and in vivo. The reproductive toxicity of vanadium in males was studied through monitoring germ cell apoptosis during spermatogenesis. We analyzed ultrastructural damage, and testosterone and progesterone concentrations following vanadium tetraoxide administered to male mice for 60 days. Spermatogenesis stages I-III and X-XII frequently showed apoptotic germ cells in control and treated animals; vanadium tetraoxide treatment induced an increase in the number of germ cell apoptosis in stages I-III and XII at 9.4 and 18.8 mg/kg, respectively. Although spermatogenesis is regulated by testosterone, in our study this hormone level was not modified by vanadium administration; thus, germ cell death was not related with testosterone concentration. At the ultrastructural level, we observed inclusion structures that varied as to location and content in the Sertoli and germ cells.

Blood-testis barrier dynamics are regulated by {alpha}2-macroglobulin via the c-Jun N-terminal protein kinase pathway

The blood-testis barrier (BTB), in contrast to the blood-brain and blood-retina barriers, is composed of coexisting tight junctions, gap junctions, and basal ectoplasmic specializations, a testis-specific type of adherens junction. Recent studies showed that BTB restructuring that facilitates germ cell migration during spermatogenesis involves proteolysis, an event that is usually restricted to the cell-matrix interface in other epithelia. For instance, a surge in alpha(2)-macroglobulin (alpha(2)-MG), a protease inhibitor produced by Sertoli cells, was detected at the Sertoli-Sertoli and Sertoli-germ cell interface in the epithelium during cadmium chloride-induced BTB disruption in adult rats. It is thus proposed that the increase in alpha(2)-MG is crucial for protecting the epithelium from unwanted proteolysis as well as regulating the availability of cytokines that affect junction turnover. Although both tight junction and adherens junction dynamics at the BTB are regulated via the p38 MAPK signaling pathway, the mechanism(s) that regulates alpha(2)-MG is entirely unknown. In this study, we have shown that by administering dimethylaminopurine, a c-Jun N-terminal protein kinase (JNK) inhibitor, to the testis, JNK activity was blocked specifically and alpha(2)-MG production was inhibited, worsening the cadmium chloride-induced damage to the epithelium. Studies coupled with inhibitors, immunoblottings, and immunofluorescent and electron microscopy have unequivocally demonstrated that the JNK signaling pathway is a putative regulatory pathway for alpha(2)-MG production in the testis. This finding illustrates for the first time that a cell-matrix restructuring event occurs in normal cell physiology at the cell-cell interface in the testis, highlighting the significance of alpha(2)-MG in the regulation of BTB function.

Effects of exposure to genistein during pubertal development on the reproductive system of male mice

Genistein, a soybean-originated isoflavone, is widely consumed by humans for putative beneficial health effects but its estrogenic activity may affect adversely the development of the male reproductive system. Twenty-one days old ICR mice weaned from dams fed with a casein-based AIN-76A diet during gestation and lactation were exposed to genistein (2.5 and 5.0 mg/kg/day, p.o.) for 5 weeks. 17beta-Estradiol (7.5 microg/kg/day) and corn oil were used for the positive and negative vehicle controls, respectively. The animals were fed the casein-based AIN-76A diet throughout the experiment. There were no significant differences in body weights of mice between the genistein groups and the negative control group. No significant differences in relative reproductive organ weights were found among all experimental groups. Sperm counts in epididymis and testes were slightly decreased in the genistein-exposed groups compared with control group. Sperm motile characteristics in genistein-exposed groups were slightly higher than those of the control group. Levels of phospholipid hydroxide glutathione peroxidase mRNA in the testis, epididymis, and prostate of mice exposed to genistein or estradiol were significantly higher than those of the controls (P<0.05). Exposure to genistein caused hyperplasia of Leydig cells in the testis and a slight increase of interstitial fibroblasts in the epididymis, while estradiol treatment caused severe damage to the testis and epididymis. These results suggest that dietary uptake of genistein during the juvenile period may affect male reproductive development, resulting in a slight decrease in sperm count, but with an increase in sperm motion quality.

Cycloheximide prevents production of arresting, a fraction of 30-50 kDa obtained from seminiferous tubule conditioned medium

AIM

To evaluate the effect of a protein synthesis inhibitor cycloheximide on arresting activity in spermatogenesis and sperm count in male rats.

METHODS

The study used seminiferous tubule (ST) segments from adult rats cultured in vitro with or without cycloheximide to condition culture media, which have been concentrated, size fractioned (30-50 kDa) and administered 7 days to adult rats by intraperitoneal injections. The effects on testicular and epididymal weights, spermatogenesis and epididymal sperm count were determined.

RESULTS

The fraction (30-50 kDa), named arresting, obtained from the culture without cycloheximide decreased testicular and epididymal weights (P<0.01) and reduced the epididymal sperm count significantly. Study of the spermatogenic cycle by transillumination showed spermatogenic arrest at stage VII in rats treated with arresting compared to that observed in controls. The length of stage VII in the group receiving the seminiferous tubules culture media with cycloheximide (30-50 KDa CHX-STCM fraction) was similar to control.

CONCLUSION

The difference in the effect may be the result of the presence or absence of arresting, a protein secreted by the tubules.

The toxic effects of nonylphenol on the reproductive system of male rats

Male Sprague-Dawley (SD) rats were exposed to 4-t-nonylphenol (NP) by gavage at dosages of 0, 125 and 250 mg/kg/day for 50 days. Organ weights of liver, kidney, testis and epididymis were measured. Sperm number in the head of epididymis was counted. Several hormones including testosterone, luteinizing hormone and follicle stimulating hormone were measured. Testicular sections were observed by light and electron microscopy. Terminal dideoxynucleotidyl transferase dUTP nick end labeling assay was performed to probe the apoptotic cells in seminiferous tubules. When rats were treated with nonylphenol at 250 mg/kg/day, the absolute and relative weight of epididymis decreased dramatically, while the relative weights of kidney and liver increased by 14 and 22%, respectively. In addition, the sperm density of the head of epididymis and the testosterone level descended at 250 mg/kg/day. The levels of luteinizing hormone and follicle stimulating hormone increased in both nonylphenol treated groups. Pathological changes were detected by microscopy and the transferase dUTP nick end labeling (TUNEL) assay showed that the number of apoptotic cells in testes increased with nonylphenol in a dose-dependent manner.

Induction of male germ cell apoptosis by testosterone withdrawal after ethane dimethanesulfonate treatment in adult rats

OBJECTIVE

To carry out a detailed quantitative analysis of male germ cell apoptosis in seminiferous epithelium in a long period after EDS administration.

METHODS

The apoptosis in adult rat testes was induced by a single i.p. injection of ethane dimethanesulphonate (EDS) in a dose of 75 mg/kg body weight. The TUNEL assay for in situ detection of apoptosis and quantitation of apoptotic germ were performed in testicular sections days 1, 3, 7, 14, 21 and 35 after EDS treatment. Plasma levels of testosterone (T) and luteinizing hormone (LH) were measured by RIA.

RESULTS

First signs of seminiferous epithelium regression were manifested by a marked increase in the number of apoptotic cells on 3rd day after EDS treatment. The maximal value of germ cell apoptosis was established on 7th day post EDS that coincided with lowest T levels. Later, until the end of investigated period, the elevated values of all investigated parameters for quantification of germ cell apoptosis decreased, but remained still higher as compared to control and, in addition, also T concentrations returned to normal range and their mean values were lower than these in controls. The pachytene spermatocytes and spermatids were the predominant cell types that underwent apoptosis after EDS treatment.

CONCLUSIONS

Quantitative patterns of germ cell death after testosterone deprivation reveal in advance the kinetic of germ cell depletion and regeneration in a long period after EDS. These new findings bring additional support to the concept that germ cell apoptosis is a hormonally regulated process. Induction of germ cell apoptosis by EDS could be considered as a result of differential alterations occurring in the main testicular cell types, more than one pathway being probably involved in that physiological cell death in the testis.

Regulation of blood-testis barrier dynamics: an in vivo study

An in vivo model was used to investigate the regulation of tight junction (TJ) dynamics in the testis when adult rats were treated with CdCl(2). It was shown that the CdCl(2)-induced disruption of the blood-testis barrier (BTB) associated with a transient induction in testicular TGF-beta2 and TGF-beta3 (but not TGF-beta1) and the phosphorylated p38 mitogen activated protein (MAP) kinase, concomitant with a loss of occludin and zonula occludens-1 (ZO-1) from the BTB site in the seminiferous epithelium. These results suggest that BTB dynamics in vivo are regulated by TGF-beta2/-beta3 via the p38 MAP kinase pathway. Indeed, SB202190, a specific p38 MAP kinase inhibitor, blocked the CdCl(2)-induced occludin and ZO-1 loss from the BTB. This result clearly illustrates that CdCl(2) mediates its BTB disruptive effects via the TGF-beta3/p38 MAP kinase signaling pathway. Besides, this CdCl(2)-induced occludin and ZO-1 loss from the BTB also associated with a significant loss of the cadherin/catenin and the nectin/afadin protein complexes at the site of cell-cell actin-based adherens junctions (AJs). An induction of alpha(2)-macroglobulin (a non-specific protease inhibitor) was also observed during BTB damage and when the seminiferous epithelium was being depleted of germ cells. These data illustrate that a primary disruption of the BTB can lead to a secondary loss of cell adhesion function at the site of AJs, concomitant with an induction in protease inhibitor, which apparently is used to protect the epithelium from unwanted proteolysis. alpha(2)-Macroglobulin was also shown to associate physically with TGF-beta3, afadin and nectin 3, but not occludin, E-cadherin or N-cadherin, indicating its possible role in junction restructuring in vivo. Additionally, the use of SB202190 to block the TGF-beta3/p-38 MAP kinase pathway also prevented the CdCl(2)-induced loss of cadherin/catenin and nectin/afadin protein complexes from the AJ sites, yet it had no apparent effect on alpha(2)-macroglobulin. These results demonstrate for the first time that the TGF-beta3/p38 MAP kinase signaling pathway is being used to regulate both TJ and AJ dynamics in the testis, mediated by the effects of TGF-beta3 on TJ- and AJ-integral membrane proteins and adaptors, but not protease inhibitors.