The changes of heavy metal and metallothionein distribution in testis induced by cadmium exposure

Zinc mitigates cadmium-induced sperm dysfunction through regulating Ca2+ and metallothionein expression in the freshwater crab Sinopotamon henanense

Cadmium (Cd) is a highly toxic heavy metal element that might adversely affect sperm function such as the acrosome reaction (AR). Although it is widely recognized that zinc (Zn) plays a crucial role in sperm quality, the complete elucidation of how Zn ameliorates Cd-induced sperm dysfunction is still unclear. In this study, we aimed to explore the protective effects of Zn against the sperm dysfunction induced by Cd in the freshwater crab Sinopotamon henanense. The results demonstrated that Cd exposure not only impaired the sperm ultrastructure, but also caused sperm dysfunction by decreasing the AR induction rate, acrosome enzyme activity, and Ca2+ content in sperm while elevating the activity and transcription expression of key Ca2+ signaling pathway-related proteins Calmodulin (CAM) and Ca2+-ATPase. However, the administration of Zn was found to alleviate Cd-induced sperm morphological and functional disorders by increasing the activity and transcription levels of CaM and Ca2+-ATPase, thereby regulating intracellular Ca2+ homeostasis and reversing the decrease in Ca2+ contents caused by Cd. Furthermore, this study was the first to investigate the distribution of metallothionein (MT) in the AR of S. henanense, and it was found that Zn can reduce the elevated levels of MT in crabs caused by Cd, demonstrating the significance of Zn in inducing MT to participate in the AR process and in metal detoxification in S. henanense. These findings offer novel perspectives and substantiation regarding the utilization of Zn as a protective agent against Cd-induced toxicity and hold significant practical implications for mitigating Cd-induced sperm dysfunction.

Exposure to low-dose cadmium induces testicular ferroptosis

As an environmental pollutant, cadmium (Cd) has been widely reported to induce male infertility due to its gonadotoxicity. However, the specific mechanism of Cd-induced testicular damage remains unclear. We investigated whether Cd causes testicular injury through ferroptosis. Male C57BL/6 J mice were exposed to 0, 0.5, or 5 ppm Cd via drinking water, starting in utero, and continuing through 24 weeks post-weaning. The results showed that Cd accumulated in the testes in a dose-dependent manner. Cd exposure at a concentration of 5 ppm, but not 0.5 ppm, caused a mass loss and detachment of germ cells, as well as a decreased meiotic index and testis weight. Exposure to 5 ppm Cd caused iron accumulation, increased levels of malondialdehyde (MDA) and nitro tyrosine (3-NT), and decreased expression of Nrf2, HO-1 and SOD2. We also found that exposure to 5 ppm Cd significantly decreased the expression of SLC7A11, a marker of ferroptosis in mice, along with the expression of SLC40A1 mRNA and ferritin heavy chain (FTH) protein, whereas there was no obvious change in the mRNA expression of Tfrc, ZIP8, ZIP14, and NCOA4. These findings indicate that 5 ppm Cd exposure increased testicular ferroptosis, which may be attributed to the reduction of stored iron export.

Molecular cloning, the characterization of metallothionein and catalase, and the evaluation of testicular toxicity of Cd in the Chinese fire-bellied newt (Cynops orientalis)

Cadmium (Cd) is an environmental toxicant and a nonessential metal. Cd can attack a wide range of organs, such as the liver, kidney, lung, ovary, testis, brain, and muscle in vertebrates. Among these organs, the testis might be the most sensitive organ to Cd toxicity. Metallothionein (MT) is a cysteine-rich protein with a low molecular weight, that can bind with Cd and eliminate reactive oxygen species (ROSs). Hydrogen peroxide, which as a crucial type of ROS that is induced by Cd, can be eliminated by catalase (CAT) in the self-protection of cells and to realize Cd toxicity resistance. To investigate the functions of MT and CAT in the testis of Cynops orientalis, we cloned the full-length MT and CAT genes of C. orientalis for the first time. Immunofluorescence results demonstrated that MT and CAT were expressed in Sertoli cells and all spermatogenic cells in the testis of C. orientalis. The results of the ultrastructural damage assay demonstrated that there were various impairments, which included organelle vacuolization, abnormal chromatin distribution, and apoptotic bodies, in somatic cells that were exposed to Cd. However, the anomalies of spermatozoa were located mainly in the mid-piece and head, many of which showed severely impaired structures. The results demonstrated that MT and CAT expression had distinct patterns in response to various Cd concentrations: an increase in MT mRNA levels with elevated Cd levels and a persistent increase in CAT mRNA levels with elevated Cd levels. These results suggested that MT and CAT play roles in Cd toxicity resistance in the testis and that the expression of CAT may be a better biomarker than the expression of MT for assessing Cd pollution.

The effect of seminal plasma cadmium and lead levels on semen parameters in male subjects of infertile couples: a prospective cohort study

The aim of this prospective study was to investigate whether there is a relationship between seminal plasma cadmium (Cd) and lead (Pb) levels and semen parameters in male partners of infertile couples. Two hundred fifty one (251) men recruited with no history of occupational exposure to toxic metals. After semen analysis, seminal Cd and Pb levels were measured using atomic absorption spectrometry. Cadmium levels in men with hypospermia was significantly higher than men with normal semen volume (p = .049). In contrast, there was no statistically significant difference in median seminal Pb levels between men with hypospermia and men with normal semen volume (p = .13). There was no statistically significant association between seminal plasma Cd and Pb levels sperm concentration, motility, morphology and total progressively motile sperm count. These findings suggest that environmental Cd exposure may contribute to low semen volume in male partners of infertile couples.IMPACT STATEMENTWhat is already known on this subject? Toxic metals may adversely affect both male and female reproductive system.What the results of this study add? Seminal plasma cadmium levels in men with hypospermia were statistically significantly higher than men with normal semen volume.What the implications are of these findings for clinical practice and/or further research? Patients should be informed about possible adverse effects of toxic metals.

Effects of the methanol root extract of Carpolobia lutea on sperm indices, acrosome reaction, and sperm DNA integrity in cadmium-induced reproductive toxicity in male Wistar rats

OBJECTIVE

Oxidative stress is a mechanism of cadmium-induced reproductive dysfunction. Carpolobia lutea is a free radical scavenger. Our study investigated the potential protective effects of Carpolobia lutea root methanol extract against cadmium-induced reproductive toxicity.

METHODS

We obtained the Carpolobia lutea root in Akure, and it was authenticated at the Forestry Research Institute of Nigeria (FRIN) herbarium, Ibadan, Nigeria, with FHI number 109784. We used Soxhlet extraction to obtain its methanol extract. We used thirty male Wistar rats (150-170g) in this study, (n=5 per group), and treated them as follows: Control (1 ml/kg normal saline), Cd (2 mg/kg), Cd+MCL (2 mg/kg+100 mg/kg), Cd+MCL (2 mg/kg+200 mg/kg), MCL (100 mg/kg), MCL (200 mg/kg). We administered Carpolobia lutea orally for 8 weeks. We administered a single dose of 2 mg/kg of cadmium intraperitoneally. We assessed the sperm profile using a computer-aided sperm analyzer. Under microscopy, we determined the sperm acrosome reaction and the DNA damage. We measured the seminal fructose level using spectrophotometry, and the data were analyzed using ANOVA at p<0.05.

RESULTS

Cd+MCL (2mg/kg+200 mg/kg) significantly increased sperm count (339.0±25.0 vs. 29.0±4.5 million/mL), motility (80.0±0.2 vs. 55.0±4.9%), viability (68.7±2.7 vs. 31.3±2.9%) and decreased abnormal sperm (28.3±1.7 vs. 43.3±2.5%), relative to the cadmium group. Cd+MCL (2mg/kg+200 mg/kg) significantly increased acrosome reaction (68.0±7.5 vs. 15.2±2.4%) and seminal fructose level (0.49±0.06 vs. 0.28±0.06 mmol/L) relative to the cadmium group. Cd+MCL (2mg/kg+200 mg/kg) significantly decreased sperm DNA damage (14.1±1.6 vs. 35.9±5.3%) in relation to the cadmium group.

CONCLUSIONS

Carpolobia lutea root extract improves the sperm variables of rats exposed to cadmium.

Multigenerational effects of cadmium on the lifespan and fertility of Drosophila melanogaster

Although the damage and tolerance mechanisms of Cd stress are known, the data on genetic risk are limited. The aim of this study was to assess the chronic toxicity of Cd, genetic responses, and multigenerational effects in five generations of Drosophila melanogaster. For each generation, lifespan and fertility were statistically analysed and the expression of apoptosis- (p53 and caspase-3) and epigenesis-related (dDnmt2 and dMBD2/3) genes was examined. Lifespan and fertility significantly declined under Cd stress and these effects were maintained for two generations and one generation, respectively, when Cd stress was removed. The expression of p53 and caspase-3 was significantly up-regulated after exposure, suggesting that apoptosis contributes to the resistance mechanism. Their altered expression was retained for two generations. Furthermore, high expression of dDnmt2 and dMBD2/3 accompanied Cd exposure, which was passed on to three generations, suggesting that genetic modifications in apoptosis-related genes are carried to the offspring through epigenetic regulation.

Role of metallothionein-like cadmium-binding protein (MTLCdBP) in the protective mechanism against cadmium toxicity in the testis

The role of metallothionein (MT)-like cadmium (Cd) binding protein (MTLCdBP) in protecting the testes against Cd toxicity was examined. In the acute Cd exposure treatment, cadmium chloride was intraperitoneally injected at 2 mg Cd/kg to Wistar male rats. In the chronic Cd toxicity treatments, 20 mg Cd/kg/d was orally administered for 5 d a week for 5, 10, and 15 wk. MT (-I,-II) and MTLCdBP were measured using ELISA and Cd-Hem methods, respectively. Testicular tissues were immunostained with antibodies of MT-I,-II, MT-III, and MTLCdBP. Expression of HO1, OGG, iNOS, COX2, and p53 was measured by RT-PCR. Cd concentration in the testis increased dose-dependently in response to Cd exposure. MTLCdBP concentration increased markedly with increasing Cd accumulation. Significant increases in expression of iNOS, HO1, COX2, and OGG1 were observed in the acute exposure treatment. In the chronic oral administration group, expression of MT-I, MT-II, MT-III, iNOS, HO1, and COX2 did not change. Positive immunostaining of MTLCdBP was observed in testicular interstitial tissue. In the testis protected from Cd toxicity, MTLCdBP induction increased significantly with increasing Cd accumulation. Our results suggest that MTLCdBP plays an important role in protecting the testis against Cd toxicity.

The protective effect of aqueous extract of Typha capensis rhizomes on cadmium-induced infertility in rats

Background Typha capensis is one of the medicinal plants commonly used to manage male fertility problems. The objective of the present study was to assess its fertility-promoting effects in a rat model of cadmium-induced infertility. Methods A total of 30 male Wister rats were randomly divided into five groups of six animals each. Animals of group I, which served as control, were administered with cadmium chloride (CdCl2; 2.5 mg/kg) and normal saline (2 mL/kg). Group II was served with 0.5 mL normal saline only. Animals of groups III-V were treated with CdCl2 (2.5 mg/kg) plus T. capensis extract at doses of 100, 200, and 400 mg/kg, respectively. Animals were sacrificed under sedation. Testes and epididymal weights and sperm count were determined. Histological assessment of the testes was conducted. Results T. capensis at any dose did not improve (p > 0.05) testicular and epididymal weights compared with those of the CdCl2-exposed control group. Histology revealed moderate necrosis in the same group. T. capensis modestly increased the sperm count by 14%, 31%, and 35%, for groups treated with the extract at doses 100, 200, and 400 mg/kg, respectively, when compared with the CdCl2 control group, although the differences were not significant statistically (p > 0.05). Conclusions Results of our study demonstrated that T. capensis can neither offer protective effects against oxidative stress nor promote fertility in an animal model of cadmium-induced infertility.

Toxic metals in seminal plasma and in vitro fertilization (IVF) outcomes

We measured toxic metals in seminal plasma collected from 30 men using vitro fertilization (IVF), to evaluate associations with semen quality and IVF outcomes. A doubling in Hg-adjusted Pb concentration was associated with 47% lower total motile sperm. Positive associations were suggested for Hg with pregnancy and live birth, adjusted for Cd or Pb. A negative association was suggested for Hg-adjusted Cd with pregnancy. These data add to evidence indicating that toxic metals impact IVF.

Saffron improves epididymal sperm parameters in rats exposed to cadmium

Background:

Cadmium (Cd) is known to cause various disorders in the testis. The general population may be exposed to Cd through ingestion of food and drinking water, inhalation of particulates from ambient air, tobacco smoke and ingestion of contaminated soil and dust. Saffron (Crocus sativus L.) is widely used as a food flavour, and has well known medicinal effects.

Objectives:

The aim of this study was to determine the effects of saffron on the results of semen parameters (sperm concentration, motility and viability in cauda of epididymis) in rats exposed to cadmium.

Materials and Methods:

Thirty Wistar male rats were divided into four groups. Cadmium chloride (1 mg/kg body weight) was injected intraperitoneally during 16 days at intervals of 48 hours between subsequent treatments. Crocus sativus L. (100 mg/kg b.w., IP) was pretreated in both control and cadmium-injected rats. Both control and cadmium-injected rats were pretreated with Crocus sativus L. (100 mg/kg b.w., IP). The animals were killed and their sperm count, motility, and vitality were evaluated.

Results:

Sperm parameters did not differ significantly between control and sham groups. Following contamination with cadmium, sperm count, motility and vitality were significantly decreased in comparison to control group (P < 0.05). In pretreated (saffron) group, the sperm parameters improved significantly in comparison with cadmium group (P ≤ 0.05). A significant decrease in sperm motility was observed in Cd-treated rats compared to the control rats. However, no significant changes were recorded by comparison of the control and saffron treated groups except for the sperm motility parameter.

Conclusions:

Saffron, as an antioxidant, is positively effective on sperm parameters in rats exposed with cadmium.

Expression and function analysis of metallothionein in the testis of Portunus trituberculatus exposed to cadmium

Metallothioneins (MTs) possess a unique molecular structure that provides metal-binding and redox capabilities. These capabilities include the maintenance of metal equilibria that protect against heavy metals (especially cadmium) and oxidative damage. Past studies have focused on the function of MTs in vertebrates. However, the functions of MTs during spermiogenesis in invertebrates remain unclear. In order to investigate the function of MTs during spermiogenesis in Portunus trituberculatus, we used RT-PCR and RACE to identify two MT complete cDNA sequences in the total RNA from the P. trituberculatus testis. The 450 bp MT-1 cDNA consists of a 77 bp 5' untranslated region, a 196 bp 3' untranslated region, and a 177 bp open reading frame that encodes 58 amino acids including 19 cysteines. The 581 bp MT-2 cDNA consists of 73 bp 5' untranslated region, a 328 bp 3' untranslated region, and a 180 bp open reading frame that encodes 59 amino acids including 18 cysteines. MT-1 and MT-2 of P. trituberculatus more closely resemble invertebrate (especially crab) MT homologues than vertebrate MT homologues as indicated by protein alignment comparisons and phylogenetic tree analysis. MT-1 and MT-2 were detected in the heart, testis, muscle, hepatopancreas, and gill of P. trituberculatus by tissue expression analysis. In addition, MT-1 and MT-2 are present during the entire process of spermiogenesis in P. trituberculatus as indicated by H&E staining and in situ hybridization. MT-1 and MT-2 expression levels significantly increase after cadmium (Cd) exposure as measured by real-time quantitative PCR analysis. Therefore, we suggest that MT-1 and MT-2 perform important functions in spermiogenesis and testis detoxification in P. trituberculatus.

Expression and function analysis of metallothionein in the testis of stone crab Charybdis japonica exposed to cadmium

Metallothionein (MT) participates in metallic homeostasis and detoxification in living animals. Previous studies have focused mainly on the functions of MT in vertebrates, but the functions of MT during spermiogenesis in invertebrates remain unclear. In order to investigate the functions of MT during spermiogenesis in the Japanese stone crab (Charybdis japonica), we identified the C. japonica MT complete cDNA sequence from the total RNA of the testis using RT-PCR and RACE. The 587 bp MT cDNA contains: an 80 bp 5' untranslated region, a 333 bp 3' untranslated region, and a 174 bp open reading frame. MT has 57 amino acids including 19 cysteines. The protein alignment between MT sequences of C. japonica and other crabs shows a high similarity and a strong identity in cysteine residues vital for the metal-binding affinity of MT. After the cadmium (Cd) exposure, the testis displays both abnormal morphology and MT mRNA expression both of which indicate a sensitive response of testis MT to Cd. Therefore, we suggest that MT is an excellent biomarker candidate for evaluating Cd pollution.

Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose-effect relationship. Moreover, the same dosages of Cd(2+) solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P<0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5-7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P<0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species.

Human spermatozoal RNAs

OBJECTIVE

To provide a focused review of the scientific literature pertaining to spermatozoal RNA.

DESIGN

Review of the literature and appraisal of relevant articles.

SETTING

Not applicable.

PATIENT(S)

Infertile male.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Spermatozoal RNAs as potential epigenetic modifiers in early embryo development and as clinical markers of male infertility.

RESULT(S)

The nucleus of mature spermatozoa contains a complex population of mRNAs and miRNAs despite its transcriptionally inert state.

CONCLUSION(S)

A specific set of functional RNAs are delivered into oocytes during fertilization and are thought to contribute extragenomically to early embryonic development. Even if spermatozoal RNAs is merely residual, it still has the potential to greatly improve the investigative and diagnostic potential of male infertility.

Elemental bioimaging in kidney by LA-ICP-MS as a tool to study nephrotoxicity and renal protective strategies in cisplatin therapies

A laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)-based methodology is presented for Pt, Cu, and Zn bioimaging on whole kidney 3 μm sagittal sections from rats treated with pharmacological doses of cisplatin, which were sacrificed once renal damage had taken place. Pt turned out to accumulate in the kidney cortex and corticomedullary junction, corresponding to areas where the proximal tubule S3 segments (the most sensitive cells to cisplatin nephrotoxicity) are located. This demonstrates the connection between platinum accumulation and renal damage proved by histological examination of HE-stained sections and evaluation of serum and urine biochemical parameters. Cu and Zn distribution maps revealed a significant displacement in cells by Pt, as compared to control tissues. A dramatic decrease in the Pt accumulation in the cortex was observed when cilastatin was coadministered with cisplatin, which can be related to its nephroprotective effect. Excellent imaging reproducibility, sensitivity (LOD 50 fg), and resolution (down to 8 μm) were achieved, demonstrating that LA-ICP-MS can be applied as a microscopic metal detector at cellular level in certain tissues. A simple and quick approach for the estimation of Pt tissue levels was proposed, based on tissue spiking.

Differential transcriptomic profile in spermatozoa achieving pregnancy or not via ICSI

Basic sperm analysis is limited as a method of estimating pregnancy. This study’s objective was use of microarray technology to differentiate the gene expressions of spermatozoa that achieved pregnancy in an intracytoplasmic sperm injection (ICSI)cycle in an oocyte donation programme with those that did not achieve pregnancy. A study of nested cases and controls was designed to evaluate fresh and frozen spermatozoa from infertile males undergoing ICSI with donor oocytes. The global genome expression of pooled samples from each group (achieving pregnancy versus those that didn’t, from fresh or frozen spermatozoa)was compared using microarray analysis. The level of expression of some of the transcripts from fresh spermatozoa was shown to differ for those that achieved pregnancy versus those that didn’t. Additionally, exclusively expressed transcripts were identified for both outcome groups. Analysis of frozen spermatozoa didn’t reveal differential expression, but exclusively expressed transcripts were detected. Lists of the transcripts were systematically analysed using different databases in order to provide information about them and their relationship with male fertility. The results revealed profound differences between the expression profiles of spermatozoa that resulted in pregnancy versus those that didn’t. These differences may explain ICSI failure associated with male factor infertility.

Analysis on the co-localization of asbestos bodies and Fas or CD163 expression in asbestos lung tissue by in-air micro-pixe

To prevent and control disease caused by exposure to various agents, it is necessary to determine the harmful level of intervention and to establish a method for measuring that level. In-air microparticle-induced X-ray emission (in-air micro-PIXE) analysis is based on irradiation of specimens with a proton ion microbeam, and has been modified for biological application. Two-dimensional analysis and quantitative analysis using the system confirmed that asbestos induced apoptosis by upregulating Fas expression and also revealed the accumulation of CD163-expressing macrophages in the lungs of patients with asbestosis. By quantitative comparison of the area of Fas or CD163 expression and the Fas- or CD163-negative area in asbestos lung tissue, the harmful levels which caused the expression of Fas or CD163 could be estimated on Silica, Ferrous iron, and Magnesium (the components of asbestos) deposition. These results indicate that the system could be useful for investigating the pathogenesis of inhaled particle-induced immune reactions and for determining harmful levels of exogenous agents.

Cadmium concentration and metallothionein expression in prostate cancer and benign prostatic hyperplasia of humans

BACKGROUND/PURPOSE

Cadmium (Cd) causes various genitourinary disorders and is a carcinogen for prostate cancer. Metallothionein (MT) is a protein that detoxifies heavy metals. We evaluated changes in Cd concentration and MT expression in human prostate cancer (CaP) and benign prostatic hyperplasia (BPH). Our goal was to clarify the relationship between Cd concentration and MT expression in prostatic diseases.

METHODS

The experimental group consisted of 18 patients who underwent radical prostatectomy for CaP. The control group consisted of 35 patients who underwent transurethral resection of the prostate for BPH. Tissue samples were acquired from the gross tumor site and from resected chips. We determined Cd concentration by atomic absorption, MT expression by immunoblotting, and immunohistochemical staining. The significance of between-group differences for these outcomes was analyzed using Student's t tests.

RESULTS

There was no statistically significant difference in Cd concentration between the CaP and BPH groups. Immunoblots from both groups revealed a single band. The relative intensity of the MT band was 0.58 +/- 0.09 in the BPH group and 0.17 +/- 0.03 in the CaP group. MT expression in patients with BPH was 3.4-fold higher than in those with CaP.

CONCLUSION

MT may bind heavy metals and protect patients from CaP. Additional studies are needed to reveal the factors that influence the expression of MT in prostate epithelial cells, and to analyze the free and compound forms of Cd at the same time.

Cadmium-induced testicular injury

Cadmium (Cd) is an environmental toxicant and an endocrine disruptor in humans and rodents. Several organs (e.g., kidney, liver) are affected by Cd and recent studies have illustrated that the testis is exceedingly sensitive to Cd toxicity. More important, Cd and other toxicants, such as heavy metals (e.g., lead, mercury) and estrogenic-based compounds (e.g., bisphenols) may account for the recent declining fertility in men among developed countries by reducing sperm count and testis function. In this review, we critically discuss recent data in the field that have demonstrated the Cd-induced toxicity to the testis is probably the result of interactions of a complex network of causes. This is likely to involve the disruption of the blood-testis barrier (BTB) via specific signal transduction pathways and signaling molecules, such as p38 mitogen-activated protein kinase (MAPK). We also summarize current studies on factors that confer and/or regulate the testis sensitivity to Cd, such as Cd transporters and metallothioneins, the impact of Cd on the testis as an endocrine disruptor and oxidative stress inducer, and how it may disrupt the Zn(2+) and/or Ca(2+) mediated cellular events. While much work is needed before a unified mechanistic pathway of Cd-induced testicular toxicity emerges, recent studies have helped to identify some of the likely mechanisms and/or events that take place during Cd-induced testis injury. Furthermore, some of the recent studies have shed lights on potential therapeutic or preventive approaches that can be developed in future studies by blocking or minimizing the destructive effects of Cd to testicular function in men.

Elevated metallothionein-bound cadmium concentrations in urine from bladder carcinoma patients, investigated by size exclusion chromatography-inductively coupled plasma mass spectrometry

Cadmium is discussed as being involved in the development of transitional cell carcinoma (TCC) of the bladder and can be observed in urine of these patients. Investigations of urinary samples from bladder cancer patients and normal controls were carried out with special emphasis on metallothionein (MT)-bound cadmium. Compounds that are constituents of urine were separated in urine samples by means of size exclusion chromatography and cadmium was monitored continuously with a hyphenated inductively coupled plasma mass spectrometry (ICP-MS) system. MT-bound cadmium was quantified by peak area integration, taking into account the intensity of the rhodium signal which was added continuously before ICP-MS detection. The obtained results show that urinary cadmium is predominantly bound to the observed MT-fraction. The median of the MT-bound cadmium concentration in the control group was found to be 0.8 microgL(-1) whereas the cancer group has a median of 1.8 microgL(-1). The variance of the data in the cancer group is much higher than in the controls. However, the urinary MT-bound cadmium is significantly elevated in the cancer group; odds-ratio test: 7.11 (95% C.I.: 1.89-26.80), taking into account the total protein content. Due to the fact that only one main cadmium-containing fraction was observed, there is no necessity to separate the MT-fraction before cadmium determination in urine samples in future studies.

In-Air Micro-Particle Induced X-ray Emission Analysis of Asbestos and Metals in Lung Tissue

Inhalation of asbestos increases the risk of lung cancer and pulmonary fibrosis. It is difficult to directly assess the distribution and content of inhaled particles in lung tissue sections. The purpose of this study is to employ an in-air micro particle induced X-ray emission (in-air micro-PIXE) system for assessment of the spatial distribution and content of asbestos and other metals in lung tissue. A proton ion-microbeam from this system was applied to irradiate lung tissue of patients with or without asbestosis, tumor tissue from both groups, and asbestos fibers ( in vitro). The content of each element composing asbestos and those of other metals were calculated and their distribution was assessed from the characteristic X-ray pattern for each element obtained after irradiation. This in-air micro-PIXE system could identify the location of asbestos bodies composed of Si, Mg, and Fe in lung tissue sections. Macrophage and lymphocytes accumulated in that area. This new system also revealed deposits of titanium, nickel, and cobalt in the lung tissues, in addition to asbestos bodies. The Si and Fe content were higher in lungs with asbestosis than in lungs without asbestosis or in tumor tissue. Analysis of asbestos fibers composed of chrysotile, crocidolite, and amosite showed that the ratios of Si, Fe, and Mg corresponded with those for the chemical structures. In-air micro-PIXE analysis is useful for assessing the distribution and quantities of asbestos bodies and also other metals in lung tissue comparing to immune-related cell localizations, and is also useful for analysis of standard asbestos fibers.

Changes of heavy metal, metallothionein and heat shock proteins in Sertoli cells induced by cadmium exposure

In this study, we examined the levels of Cadmium (Cd), iron (Fe) and zinc (Zn), which were considered to be involved in Sertoli cell damage caused by Cd exposure. We also examined metallothionein (MT), heat shock protein 70 (Hsp70) and heme oxygenase-1 (HO-1) expressions in Sertoli cells induced by Cd exposure. Evaluation by the in-air micro-particle induced X-ray emission (PIXE) method revealed that Cd and Fe distribution was increased in the cytoplasm of Sertoli cells after Cd exposure. By contrast, Zn was decreased in the cytoplasm of Sertoli cells after Cd exposure. It was suggested that the target of Cd toxicity was the cytoplasm of Sertoli cells, Fe was considered to enhance damage to Sertoli cells caused by Cd exposure. The DNA fragmentation rate was determined by ELISA after Cd exposure to Sertoli cells. It remained essentially unchanged with 2.5 microM Cd exposure of Sertoli cells; however, MT, Hsp70 and HO-1 were significantly increased by Cd exposure. As a result, Cd-induced MT was protected Sertoli cells against apoptosis, and Cd-induced HO-1 was involved in protection against oxidative stress. Incidentally, MT, Hsp70 and HO-1 showed similar responses to Cd exposure.