Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms.

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 µM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

Irradiation affects germ and somatic cells in prepubertal monkey testis xenografts.

Study question: Does irradiation evoke adverse effects in germ and somatic cells in testis xenografts from prepubertal monkeys? Summary answer: In addition to the expected depletion of germ cells, a dose-dependent effect of irradiation was observed at the mRNA and protein level in Sertoli and peritubular myoid cells. What is known already: Testicular irradiation studies in monkeys have focused on the dose-dependent effects on germ cells. Previous studies using intact animals or xenografts reported that germ cells are highly sensitive to irradiation. Their depletion was demonstrated by morphometric and histological analyses. The effect of irradiation on expression of Sertoli and peritubular myoid cell markers, however, has not yet been described. Study design, size, duration: The testes of two prepubertal macaques (Macaca fascicularis) were dissected into testicular fragments. Fragments were randomly exposed in vitro to one of the following three doses of irradiation: 0 Gy, n = 60; 1 Gy, n = 54; 4 Gy, n = 72. Non-irradiated control fragments (0 Gy) were placed into the Faxitron for 6.6 min without irradiation. For 1 Gy and 4 Gy irradiation was applied for 1.7 and 6.6 min, respectively. Grafts were then either immediately analyzed or subcutaneously implanted under the back skin of 39 nude mice and analyzed after 6.5 months. Participants/materials setting methods: Post grafting, 133 testicular xenografts were retrieved. The body weight, serum testosterone level and seminal vesical weight of the host mice as well as the number and weight of retrieved grafts were determined. Larger grafts were used to evaluate both mRNA expression profiles and protein expression patterns. In total, 71 testicular fragments were used for morphometric and histological analysis while 68 fragments were analyzed for gene expression. For PCR arrays, M. fascicularis-specific primer sequences were employed. Irradiation-induced changes in the transcript levels of 34 marker genes were determined for each testicular graft. The effects of irradiation on peritubular myoid cells and Sertoli cells were confirmed by immunohistochemical analysis of chemokine (C-X-C motif) ligand type 11 (CXCL11), alpha smooth muscle actin (SMA) and chemokine (C-X-C motif) ligand type 12 (CXCL12). Main results and the role of chance: The four testes gave rise to 106 xenografts, which were individually analyzed, limiting the role of chance despite using only two monkeys in the study. Prior to grafting, the two donors displayed spermatogonia as the most advanced germ cell type in 95% and 70% of seminiferous tubules, respectively, while remaining tubules contained SCO. No spermatocytes were encountered prior to grafting in either monkey. After 6.5 months, non-irradiated grafts displayed spermatocytes in 15.4% and 1.8% of seminiferous tubules indicating an induction of meiosis. Irradiation resulted in a complete absence of spermatocytes. The percentage of seminiferous tubules containing spermatogonia declined in a dose-dependent manner. In non-irradiated xenografts, ~40% of tubules contained spermatogonia. This proportion was reduced to 3.4% and 4.3% in the 1 Gy treated group and to 1.3% and 0.2% in 4 Gy irradiated grafts. A dose-dependent decline in mRNA levels of selected germ cell marker genes supported the morphologically detected loss of germ cells. Irradiation had no effect on CXCL12 transcript levels. At the protein level, CXCL12-positive Sertoli cells were most abundant in the 1 Gy group compared to the 4 Gy group (P < 0.05), indicating a potential role of CXCL12 during recovery of primate spermatogenesis. The most prominent radiation-evoked changes were for CXCL11, which was localized to smooth muscle cells of blood vessels and seminiferous tubules. Transcript levels declined in a dose-dependent manner in grafts from both monkeys (MM687: P < 0.01 (0 Gy versus 4 Gy), MM627: P < 0.05 (0 Gy versus 4 Gy), P < 0.001 (1 Gy versus 4 Gy)). CXCL11 patterns of protein expression revealed irradiation-dependent changes as well. That peritubular cells are affected by X-irradiation was substantiated by changes at the transcript level between 1 and 4 Gy exposed groups (P < 0.01) and at the protein level of SMA (P < 0.05, 0 Gy versus 4 Gy). Large scale data: n/a. Limitations, reasons for caution: The spermatogonial stem cell system in primates is remarkably different from rodents. Therefore, data from a non-human primate may be more relevant to man. However, species-specific differences amongst primates cannot be fully excluded and the use of only two donors may raise concerns toward the generalization of the findings. There may also be important differences across the prepubertal period (e.g. infancy, early childhood) that are not represented by the ages included in the present study. Wider implications of the findings: This study is the first to indicate relevant testicular somatic cell responses following irradiation of prepubertal primate tissue. In addition to the well-known depletion of germ cells, the changes in Sertoli, and in particular peritubular myoid, cells may have important consequences for spermatogenic recovery. These novel findings should be taken into consideration when irradiation effects are assessed in tumor survivors. Study funding and competing interest(s): Interdisciplinary Center for Clinical Research (IZKF) Münster (Schl2/001/13) and the Excellence Cluster 'Cells in Motion' at the University Münster. There are no conflicts of interest to declare.

Radiofrequency radiation (900 MHz)-induced DNA damage and cell cycle arrest in testicular germ cells in swiss albino mice.

Even though there are contradictory reports regarding the cellular and molecular changes induced by mobile phone emitted radiofrequency radiation (RFR), the possibility of any biological effect cannot be ruled out. In view of a widespread and extensive use of mobile phones, this study evaluates alterations in male germ cell transformation kinetics following RFR exposure and after recovery. Swiss albino mice were exposed to RFR (900 MHz) for 4 h and 8 h duration per day for 35 days. One group of animals was terminated after the exposure period, while others were kept for an additional 35 days post-exposure. RFR exposure caused depolarization of mitochondrial membranes resulting in destabilized cellular redox homeostasis. Statistically significant increases in the damage index in germ cells and sperm head defects were noted in RFR-exposed animals. Flow cytometric estimation of germ cell subtypes in mice testis revealed 2.5-fold increases in spermatogonial populations with significant decreases in spermatids. Almost fourfold reduction in spermatogonia to spermatid turnover (1C:2C) and three times reduction in primary spermatocyte to spermatid turnover (1C:4C) was found indicating arrest in the premeiotic stage of spermatogenesis, which resulted in loss of post-meiotic germ cells apparent from testis histology and low sperm count in RFR-exposed animals. Histological alterations such as sloughing of immature germ cells into the seminiferous tubule lumen, epithelium depletion and maturation arrest were also observed. However, all these changes showed recovery to varied degrees following the post-exposure period indicating that the adverse effects of RFR on mice germ cells are detrimental but reversible. To conclude, RFR exposure-induced oxidative stress causes DNA damage in germ cells, which alters cell cycle progression leading to low sperm count in mice.

Impact of 2.45 GHz microwave radiation on the testicular inflammatory pathway biomarkers in young rats: The role of gallic acid.

The aim of this study was to investigate electromagnetic radiation (EMR) transmitted by wireless devices (2.45 GHz), which may cause physiopathological or ultrastructural changes, in the testes of rats. We addressed if the supplemental gallic acid (GA) may reduce these adverse effects. Six-week-old male Sprague Dawley rats were used in this study. Forty eight rats were equally divided into four groups, which were named: Sham, EMR only (EMR, 3 h day-1 for 30 days), EMR + GA (30 mg/kg/daily), and GA (30 mg/kg/daily) groups. Malondialdehyde (MDA) and total oxidant status (TOS) levels increased (p = 0.001 for both) in EMR only group. TOS and oxidative stress index (OSI) levels decreased in GA treated group significantly (p = 0.001 and p = 0.045, respectively). Total antioxidant status (TAS) activities decreased in EMR only group and increased in GA treatment group (p = 0.001 and p = 0.029, respectively). Testosterone and vascular endothelial growth factor (VEGF) levels decreased in EMR only group, but this was not statistically significant. Testosterone and VEGF levels increased in EMR+GA group, compared with EMR only group (p = 0.002), and also increased in GA group compared with the control and EMR only group (p = 0.044 and p = 0.032, respectively). Prostaglandin E2 (PGE2 ) and calcitonin gene releated peptide (CGRP) staining increased in tubules of the testes in EMR only group (p < 0.001 for both) and decreased in tubules of the testes in EMR+GA group (p < 0.001 for all parameters). In EMR only group, most of the tubules contained less spermatozoa, and the spermatozoon counts decreased in tubules of the testes. All these findings and the regenerative reaction, characterized by mitotic activity, increased in seminiferous tubules cells of the testes in EMR+GA group (p < 0.001). Long term EMR exposure resulted in testicular physiopathology via oxidative damage and inflammation. GA may have ameliorative effects on the prepubertal rat testes physiopathology. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1771-1784, 2016.

Mobile phone radiation during pubertal development has no effect on testicular histology in rats.

Mobile phones are extensively used throughout the world. There is a growing concern about the possible public health hazards posed by electromagnetic radiation emitted from mobile phones. Potential health risk applies particularly to the most intensive mobile phone users-typically, young people. The aim of this study was to investigate the effects of mobile phone exposure to the testes, by assessing the histopathological and biochemical changes in the testicular germ cells of rats during pubertal development. A total of 12 male Sprague Dawley rats were used. The study group (n = 6) was exposed to a mobile phone for 1 h a day for 45 days, while the control group (n = 6) remained unexposed. The testes were processed with routine paraffin histology and sectioned. They were stained with hematoxylin-eosin, caspase 3, and Ki-67 and then photographed. No changes were observed between the groups (p > 0.05). The interstitial connective tissue and cells of the exposed group were of normal morphology. No abnormalities in the histological appearance of the seminiferous tubules, including the spermatogenic cycle stage, were observed. Our study demonstrated that mobile phones with a low specific absorption rate have no harmful effects on pubertal rat testicles.

[Cellphone electromagnetic radiation damages the testicular ultrastructure of male rats].

OBJECTIVE: To investigate the influence of cellphone electromagnetic radiation (CER) on the testicular ultrastructure and the apoptosis of spermatogenic cells in male rats.atability, feasibility, applicability, and controllability in the construction of experimental animal models, we compared the major anatomic features of the penis of 20 adult beagle dogs with those of 10 adult men. Using microsurgical techniques, we performed cross-transplantation of the penis in the 20 (10 pairs) beagle dogs and observed the survival rate of the transplanted penises by FK506+MMF+MP immune induction. We compared the relevant indexes with those of the 10 cases of microsurgical replantation of the amputated penis. METHODS: Thirty adult male SD rats were equally randomized into a 2 h CER, a 4 h CER, and a normal control group, the former two groups exposed to 30 days of 900 MHz CER for 2 and 4 hours a day, respectively, while the latter left untreated. Then the changes in the ultrastructure of the testis tissue were observed under the transmission electron microscope and the apoptosis of the spermatogenic cells was determined by TUNEL. RESULTS: Compared with the normal controls, the rats of the 2 h CER group showed swollen basement membrane of seminiferous tubules, separated tight junction of Sertoli cells, increased cell intervals, apparent vacuoles and medullization in some mitochondria, and increased apoptosis of spermatogenic cells, mainly the apoptosis of primary spermatocytes (P<0.05 ). In comparison with the 2 h CER group, the animals of the 4 h CER group exhibited swollen basement membrane of seminiferous tubules, more separated tight junction of Sertoli cells, wider cell intervals, incomplete membrane of spermatogonial cells, fragments of cytoplasm, nuclear pyknosis and notch, slight dilation of perinuclear space, abnormalities of intracellular mitochondria with vacuoles, fuzzy structure, and fusion or disappearance of some cristae, and increased damage of mitochondria and apoptosis of spermatogenic cells, including the apoptosis of spermatogonial cells, primary spermatocytes, and secondary spermatocytes (P<0.05 ). CONCLUSIONS: CER can damage the testicular ultrastructure and increase the apoptosis of spermatogenic cells of the male rat in a time-dependent manner, and the apoptosis of spermatogenic cells may be associated with the damage to mitochondria.

Effects of extremely low-frequency electromagnetic fields (ELF-EMF) exposure on B6C3F1 mice.

OBJECTIVE: Long-term exposure study was conducted to investigate the effects of extremely low-frequency electromagnetic field on the tumor promotion process and fertility. METHODS: Ten pregnant C57BL/6NCrj mice were exposed to 50 Hz field 500 mG for 1 week (12 h per day), and 24 male and 42 female B6C3F1mice born from them were further exposed up to 15.5 months. As a control group, 10 pregnant mice were bred without exposure, and 30 produced male and 32 female mice were observed without exposure for the same period. RESULTS: Mean body weights of exposed groups of male and female mice were decreased significantly than those of the control groups. In exposed mice, there was no increased incidence of liver and lung tumor. In female mice, the incidence of chronic myeloid leukemia [3/42 (7%)] in the exposed group was significantly greater than in the control group. The size of seminiferous tubules in the EMF exposed groups were significantly less than the control group. CONCLUSIONS: These data support the hypothesis that long-term exposure of 50 Hz magnetic fields is a significant risk factor for neoplastic development and fertility in mice.

Effects of testosterone treatment on recovery of rat spermatogenesis after irradiation.

OBJECTIVE: To determine the effects of two different radiation doses on sperm parameters and the role of testosterone treatment on rat spermatogenesis. METHODS: The experimental animal study was conducted at Marmara University, Istanbul, Turkey, from September 2012 to January 2013. Male Sprague Dawley 4-6 months old rats weighing 300-350g were randomely divided into 5 equal groups as control, low dose irradiation, testosterone administration following low dose irradiation, high dose irradiation, and testosterone administration following high dose irradiation. The animals were kept at a constant temperature in a room with 12h light and dark cycles. After the group-wise intervention, sperm concentration, testicular size, and histopathological examination of seminiferous tubules were noted. SPSS 10 was used for statistical analysis. RESULTS: The 40 rats in the study were divided in 5 groups of 8(20%) each. In low dose radiation, adverse effects were only temporarily observed with the return of almost normal testicular function at the end of two months with or without testosterone supplementation. In contrast, in high dose radiation, hormonal treatment effect was controversial. CONCLUSIONS: Testosterone treatment had no significant effect upon recovery after irradiation. In order to prevent the untoward effects of radiation, shielding of the remaining testis in a proper manner is crucial to avoid the harmful effects of the scattered radiation.

[Protective effect of Liuweidihuang Pills against cellphone electromagnetic radiation-induced histomorphological abnormality, oxidative injury, and cell apoptosis in rat testes].

OBJECTIVE: To observe the effect of Liuweidihuang Pills in relieving cellphone electromagnetic radiation-induced histomorphological abnormality, oxidative injury, and cell apoptosis in the rat testis. METHODS: Thirty adult male SD rats were equally randomized into a normal, a radiated, and a Liuweidihuang group, the animals in the latter two groups exposed to electromagnetic radiation of 900 MHz cellphone frequency 4 hours a day for 18 days. Meanwhile, the rats in the Liuweidihuang group were treated with the suspension of Liuweidihuang Pills at 1 ml/100 g body weight and the other rats intragastrically with the equal volume of purified water. Then all the rats were killed for observation of testicular histomorphology by routine HE staining, measurement of testicular malondialdehyde (MDA) and glutathione (GSH) levels by colorimetry, and determination of the expressions of bax and bcl-2 proteins in the testis tissue by immunohistochemistry. RESULTS: Compared with the normal controls, the radiated rats showed obviously loose structure, reduced layers of spermatocytes, and cavitation in the seminiferous tubules. Significant increases were observed in the MDA level (P < 0.01) and bax expression (P < 0.01) but decreases in the GSH level (P < 0.01) and bcl-2 expression (P < 0.01) in the testis issue of the radiated rats. In comparison with the radiated rats, those of the Liuweidihuang group exhibited nearly normal testicular structure, significantly lower MDA level (P < 0.05), bax expression (P < 0.01), and bcl-2 expression (P < 0.01). CONCLUSION: Liuweidihuang Pills can improve cellphone electromagnetic radiation-induced histomorphological abnormality of the testis tissue and reduce its oxidative damage and cell apoptosis.

Carnosine mitigates apoptosis and protects testicular seminiferous tubules from gamma-radiation-induced injury in mice.

This study investigated the radioprotective effects of a naturally occurring dipeptide, carnosine, on testicular damage. Carnosine was administered (10, 50 and 100 mg kg(-1) body weight) to male mice via intraperitoneal injection for 4 days prior to gamma irradiation (2 Gy). Apoptosis with the TUNEL assay and histopathological parameters were evaluated 12-h and 14-day post-irradiation. Pre-treatment with carnosine before irradiation significantly reduced the frequency of TUNEL-positive cells induced by radiation treatment at all doses by reduction factors of 1.8, 2.47 and 2.23 for carnosine at 10, 50 and 100 mg kg(-1) bw, respectively, unlike that observed in the radiation alone group. Exposure to ionising radiation decreased sperm count and reduced the height and diameter of seminiferous epithelial tubules. Pre-treatment with all doses of carnosine significantly augmented seminiferous epithelial height and tubule diameter and also increased the number of germinal cells in comparison to the group treated with radiation only. These results indicate that carnosine prevents testicular dysfunction induced by gamma-irradiation via an anti-apoptotic effect; this restoration of proper testicular function ultimately leads to the recovery of spermatogenesis.

[Radiation-induced oxidative stress and claudin-11 mRNA expression in the testis].

OBJECTIVE: To investigate the role of claudin-11, a tight junction component of Sertoli cells, in spermatogenic dysfunction induced by oxidative stress in mice exposed to local radiation. METHODS: We randomly allocated 48 male Kunming mice to a blank control group (A) and three radiation groups (B, C and D) of equal number, the latter three exposed to local radiation of the lower abdomen with 2 Gy, 6 Gy and 10 Gy of 60Co-gamma-ray, respectively, to induce oxidative stress. Four weeks later, we killed the animals, obtained their body and testis weights, observed the histological changes of the testis by HE staining, measured the levels of serum FSH, testosterone and LH by ELISA, and determined the mRNA levels of claudin-11 and inhibin beta B in Sertoli cells by real time quantitative PCR. RESULTS: After exposure to 60Co-gamma-ray radiation, the testis weights were (129.4 +/- 10.81), (87.5 +/- 16.83) and (56.1 +/- 12.36) mg in groups B, C and D, significantly decreased as compared with (182.9 +/- 8.43) mg in group A (P < 0.05); the testis indexes were (3.39 +/- 0.57), (2.46 +/- 0.46) and (1.63 +/- 0.44) mg/g in groups B, C and D, remarkably lower than (4.28 +/- 0.31) mg/g in group A (P < 0.01). Histological analysis revealed obviously decreased diameters of seminiferous tubules, reduced seminiferous epithelia and disarranged spermatogenic cells in the three radiation groups. The tubule differentiation indexes (TDI) were markedly lower in groups B, C and D than in A (P < 0.01). The levels of serum FSH were (6.74 +/- 1.95), (8.41 +/- 2.44) and (10.93 +/- 3.16) IU/L in groups B, C and D, 1.9 times higher in D than in A. With increased dose of radiation, the mRNA levels of inhibin beta in the testis tissue were descended, while the transcription levels of claudin-11 elevated, significantly higher in groups C and D than in A (P < 0.01). CONCLUSION: Local radiation-induced testicular oxidative stress can decrease the mRNA level of inhibin beta , increase serum FSH, damage Sertoli cells and elevate the expression of claudin-11 in the testis tissue. Increased claudin-11 and serum FSH may delay the cyclical restitution of hemo-testicular barrier and reduce the number of meiotic spermatocytes in the seminiferous epithelium, which consequently leads to male infertility.

An experimental approach to comprehend the influence of platelet rich growth factors on spermatogenesis.

MATERIALS AND METHODS: Experimental animals (n = 135) were divided into 5 groups: I - control (n = 10); II - 2IR (n = 35; 2 Gy); III - 2IR + LP-PRP + IGF-1 (n = 30); IV - 2IR + LP-PRP (n = 30); V - LP-PRP (n = 30). RESULTS: Electron irradiation reduces the number of germ cells in comparison with the control group. After injection of LP-PRP + rhIGF-1 significantly increased the number of germ cells, Sertoli and Leydig cells, the height of germinal epithelium, area and diameter of seminiferous tubules. CONCLUSION: LP-PRP + rhIGF-1 has a normalizing effect on structural and functional disorders of the testis caused by electron irradiation.

The potential adverse effect of 2.45 GHz microwave radiation on the testes of prenatally exposed peripubertal male rats.

In utero development of organs is easily influenced by many environmental factors. The aim of this study was to elucidate the effect of microwave radiation (MR) at a frequency of 2.45 GHz and a specific absorption rate of 1.73 W/kg on intrauterine development of testis. Pregnant albino rats were exposed to whole-body MR for 2 hours per day throughout the pregnancy. Male offspring (n=12, age 35 days) were not exposed to MR after birth. The study revealed that MR applied in utero induced apparent structural changes in the testes, such as irregular shape of seminiferous tubules, significant decrease in the diameter of seminiferous tubules (p<0.05) and in the height of the germinal epithelium (p<0.01), disorganisation of germ cells, desquamations of immature germ cells, formation of giant multinucleated cells, and significant (p<0.01) expansion of the interstitium. At the level of transmission electron microscopy, there were observed basement membrane irregularities in seminiferous tubules, vacuolation of the cytoplasm and adversely affected organelles in Sertoli cells, germ cells, Leydig cells, peritubular and endothelial cells. The tight junctions between adjacent Sertoli cells were often incomplete, and necrotizing germ cells were more numerous in experimental animals compared to controls. Enhanced necrotizations of germ cells proved by a Fluoro Jade C method, and declined germ cells proliferation confirmed by proliferating cell nuclear antigen analysis, were detected in MR exposed animals. Our results revealed that the prenatal exposure to MR had an adverse effect on the postnatal testicular development in rats.

Testicular recovery after irradiation differs in prepubertal and pubertal non-human primates, and can be enhanced by autologous germ cell transplantation.

BACKGROUND: Although infertility is a serious concern in survivors of pediatric cancers, little is known about the influence of the degree of sexual maturation at the time of irradiation on spermatogenic recovery after treatment. Thus, we address this question in a non-human primate model, the rhesus monkey (Macaca mulatta). METHODS: Two pubertal (testis size 3 and 6.5 ml, no sperm in ejaculate) and four prepubertal (testis size 1 ml, no sperm in ejaculate) macaques were submitted to a single fraction of testicular irradiation (10 Gy). Unilateral autologous transfer of cryopreserved testis cells was performed 2 months after irradiation. Testicular volume, histology and semen parameters were analyzed to assess irradiation effects and testicular recovery. RESULTS: Irradiation provoked acute testis involution only in the two pubertal monkeys. Subsequently, testis sizes recovered and sperm was present in the ejaculates. Longitudinal outgrowth of seminiferous tubules continued, and, in testes without autologous cell transfer, 4-22% of tubular cross sections showed spermatogenesis 2 years after irradiation. In contrast, the four prepubertal monkeys showed neither a detectable involution as direct response to irradiation, nor a detectable growth of seminiferous tubules later. However, two of these animals showed spermarche 2 years after irradiation, and 8-12% of tubules presented spermatogenesis. One prepubertally irradiated monkey presented fast growth of one testis after cell transfer, and showed spermarche 1 year after irradiation. The infused testis had spermatogenesis in 70% of the tubules. The contralateral testis remained smaller. CONCLUSION: We conclude that irradiation before puberty has a severe detrimental effect on outgrowth of seminiferous tubules. But, within the seminiferous epithelium, spermatogenetic recovery occurs at a low rate with no detectable relation to the maturity of the epithelium at irradiation. We also show that autologous testis cell transplantation can enhance spermatogenesis, but only in isolated cases.

Testicular development evaluation in rats exposed to 60 Hz and 1 mT electromagnetic field.

Society has been increasingly exposed to low-frequency electromagnetic fields (EMF), mainly from electricity distribution networks and electro-electronic devices. Aiming to clarify the extension of possible interactions between EMF and testicular development, this study evaluated the effects of exposure to 60 Hz and 1 mT EMF in the maturation of testicular components. Wistar rats were exposed to EMF three times per day for 30 min, between the 13th day of gestation and the 21st postnatal day. Results showed a decrease in the following parameters: tubular diameter and seminiferous tubules area; seminiferous epithelium height; total volume of seminiferous tubule; tubular lumen; seminiferous epithelium; and Leydig cells. On the other hand, an increase was observed in connective tissue cells and blood vessels volume. Plasma testosterone, Sertoli cells population, tubular length and gonadosomatic index did not change when exposed to EMF. Histomorphometric analysis showed that exposure to EMF can promote a delay in testicular development.

Protection of spermatogenesis against gamma ray-induced damage by granulocyte colony-stimulating factor in mice.

The radioprotective effects of granulocyte colony-stimulating factor (GCSF) were further investigated with respect to the testicular system. Recombinant human GCSF (100 µg kg(-1) body weight/day) was administrated to male C3H/HeN mice by subcutaneous injection for three consecutive days before pelvic irradiation (5 Gy) and histopathological parameters were assessed at 12 h and 21 days post-irradiation (pi). The GCSF protected the germ cells from radiation induced- apoptosis (P < 0.01 vs. irradiated group at 12 h pi). GCSF remarkably attenuated radiation-induced reduction in testis weight, seminiferous tubular diameter, seminiferous epithelial depth and sperm head count in the testes (P < 0.05 versus irradiated group at 21 days pi). Repopulation index and stem cell survival index of the seminiferous tubules were increased in the GCSF-treated group when compared with the radiation group (P < 0.01). The frequency of abnormal sperm in the GCSF group was lower than that in the irradiated group at 21 days pi (P < 0.01). The decrease in the sperm count and in sperm liability in the epididymis caused by irradiation was counteracted by GCSF. The present study suggests that GCSF protects from radiation-induced testicular dysfunction via an anti-apoptotic effect and recovery of spermatogenesis.

Testicular apoptosis and histopathological changes induced by a 2.45 GHz electromagnetic field.

There is a growing public concern about the potential human health hazard caused by exposure to electromagnetic radiation (EMR). The objective of this study is to investigate the effects of 2450 mhz electromagnetic field on apoptosis and histopathological changes on rat testis tissue. Twelve-week-old male Wistar Albino rats were used in this study. Eighteen rats equally divided into three different groups which were named group I, II and III. Cage control (group I), sham control (group II) and 2.45 GHz EMR (group III) groups were formed. Group III were exposed to 2.45 GHz EMR, at 3.21 W/kg specific absorption rate for 60 minutes/ day for 28 days. There was no difference among the groups for the diameter of the seminiferous tubules, pyknotic, karyolectic and karyotic cells. However, the number of Leydig cells of testis tissue of the rats in group III was significantly reduced comparing with the group I (p < 0.05). Estimation of spermatogenesis using the Johnsen testicular biopsy score revealed that the difference between groups is statistically significant. The level of TNF-α, Caspase-3 and Bcl-2 were compared, and no significant difference was found between the groups. When Bax apoptosis genes and Caspase-8 apoptosis enzyme were compared, there were significant differences between the groups (p < 0.05). Electromagnetic field affects spermatogenesis and causes to apoptosis due to the heat and other stress-related events in testis tissue.

Potential influence of prenatal 2.45 GHz radiofrequency electromagnetic field exposure on Wistar albino rat testis.

An ever-increasing use of wireless devices over the last decades has forced scientists to clarify their impact on living systems. Since prenatal development is highly sensitive to numerous noxious agents, including radiation, we focused on the assessment of potential adverse effects of microwave radiation (MR) on testicular development. Pregnant Wistar albino rats (3 months old, weighing 282±8 g) were exposed to pulsed MR at a frequency of 2.45 GHz, mean power density of 2.8 mW/cm², and a specific absorption rate of 1.82 W/kg for 2 hours/day throughout pregnancy. Male offspring were no longer exposed to MR following birth. Samples of biological material were collected after reaching adulthood (75 days). In utero MR exposure caused degenerative changes in the testicular parenchyma of adult rats. The shape of the seminiferous tubules was irregular, germ cells were degenerated and often desquamated. The diameters of the seminiferous tubules and the height of the germinal epithelium were significantly decreased (both at ∗∗p<0.01), while the interstitial space was significantly increased (∗∗p<0.01) when compared to the controls. In the group of rats prenatally exposed to MR, the somatic and germ cells were rich in vacuoles and their organelles were often altered. Necrotizing cells were more frequent and empty spaces between Sertoli cells and germ cells were observed. The Leydig cells contained more lipid droplets. An increased Fluoro Jade - C and superoxide dismutase 2 positivity was detected in the rats exposed to MR. Our results confirmed adverse effects of MR on testicular development.

BAX and tumor suppressor TRP53 are important in regulating mutagenesis in spermatogenic cells in mice.

During the first wave of spermatogenesis, and in response to ionizing radiation, elevated mutant frequencies are reduced to a low level by unidentified mechanisms. Apoptosis is occurring in the same time frame that the mutant frequency declines. We examined the role of apoptosis in regulating mutant frequency during spermatogenesis. Apoptosis and mutant frequencies were determined in spermatogenic cells obtained from Bax-null or Trp53-null mice. The results showed that spermatogenic lineage apoptosis was markedly decreased in Bax-null mice and was accompanied by a significantly increased spontaneous mutant frequency in seminiferous tubule cells compared to that of wild-type mice. Apoptosis profiles in the seminiferous tubules for Trp53-null were similar to control mice. Spontaneous mutant frequencies in pachytene spermatocytes and in round spermatids from Trp53-null mice were not significantly different from those of wild-type mice. However, epididymal spermatozoa from Trp53-null mice displayed a greater spontaneous mutant frequency compared to that from wild-type mice. A greater proportion of spontaneous transversions and a greater proportion of insertions/deletions 15 days after ionizing radiation were observed in Trp53-null mice compared to wild-type mice. Base excision repair activity in mixed germ cell nuclear extracts prepared from Trp53-null mice was significantly lower than that for wild-type controls. These data indicate that BAX-mediated apoptosis plays a significant role in regulating spontaneous mutagenesis in seminiferous tubule cells obtained from neonatal mice, whereas tumor suppressor TRP53 plays a significant role in regulating spontaneous mutagenesis between postmeiotic round spermatid and epididymal spermatozoon stages of spermiogenesis.

Melatonin modulates acute testicular damage induced by carbon ions in mice.

The present study was performed to obtain evidence of the radioprotective function of melatonin at different administration levels on carbon ion-induced mouse testicular damage. Outbred Kun-Ming strain mice were divided into six groups, each composed of eight animals: control group, melatonin alone group, irradiation group and three melatonin plus irradiation-treated groups. An acute study was carried out to determine alterations in DNA-single strand break, cell apoptosis, and oxidative stress parameters as well as histopathology in mouse testis 24 h after whole-body irradiation with a single dose of 4 Gy. The results showed that pre-treatment and post-treatment with high-dose melatonin (10 mg/kg) both significantly alleviated carbon ion-induced acute testicular damage, a greater radioprotective effect being observed in the pre-treatment group. On the other hand, low-dose melatonin (1 mg/kg) had a limited radioprotective effect on irradiation-induced degeneration and DNA lesions in mouse testis. Taken together, the data suggest that prophylactic treatment with a higher dose of melatonin is probably advisable to protect against the effects of heavy-ion irradiation.