Cadmium toxicity at low concentration on rabbit spermatozoa motility, morphology and membrane integrity in vitro

Lead and calcium crosstalk tempted acrosome damage and hyperpolarization of spermatozoa: signaling and ultra-structural evidences

BACKGROUND

Exposure of humans and animals to heavy metals is increasing day-by-day; thus, lead even today remains of significant public health concern. According to CDC, blood lead reference value (BLRV) ranges from 3.5 µg/dl to 5 μg/dl in adults. Recently, almost 2.6% decline in male fertility per year has been reported but the cause is not well established. Lead (Pb2+) affects the size of testis, semen quality, and secretory functions of prostate. But the molecular mechanism(s) of lead toxicity in sperm cells is not clear. Thus, present study was undertaken to evaluate the adverse effects of lead acetate at environmentally relevant exposure levels (0.5, 5, 10 and 20 ppm) on functional and molecular dynamics of spermatozoa of bucks following in vitro exposure for 15 min and 3 h.

RESULTS

Lead significantly decreased motility, viable count, and motion kinematic patterns of spermatozoa like curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency and maximum amplitude of head lateral displacement even at 5 ppm concentration. Pb2+ modulated intracellular cAMP and Ca2+ levels in sperm cells through L-type calcium channels and induced spontaneous or premature acrosome reaction (AR) by increasing tyrosine phosphorylation of sperm proteins and downregulated mitochondrial transmembrane potential. Lead significantly increased DNA damage and apoptosis as well. Electron microscopy studies revealed Pb2+ -induced deleterious effects on plasma membrane of head and acrosome including collapsed cristae in mitochondria.

CONCLUSIONS

Pb2+ not only mimics Ca2+ but also affects cellular targets involved in generation of cAMP, mitochondrial transmembrane potential, and ionic exchange. Lead seems to interact with Ca2+ channels because of charge similarity and probably enters the sperm cell through these channels and results in hyperpolarization. Our findings also indicate lead-induced TP and intracellular Ca2+ release in spermatozoa which in turn may be responsible for premature acrosome exocytosis which is essential feature of capacitation for fertilization. Thus, lead seems to reduce the fertilizing capacity of spermatozoa even at 0.5 ppm concentrations.

Histopathological Findings of Testicular Tissue Following Cadmium Toxicity in Rats

Background & Objective:

Reproductive toxicity of cadmium (Cd) as an environmental toxicant has been proved in animals and humans. Exposure to Cd impairs testes organs and can reduce male fertility. The present study was designed to investigate the spectrum of histopathological changes in testicular tissue focusing on Sertoli cells in rats following Cd intoxication.

Methods:

In the present experiment, acute testicular toxicity was induced by an intraperitoneal injection of 1.2 mg/kg CdCl₂ to the animals in the test group, while the control group received normal saline. After 52 days, the animals were euthanized, and testicular tissue was stained by Hematoxylin and Eosin. In addition, immunohistochemical staining was performed on Sertoli cells for Wilms' Tumor, Melan-A, and CD99 to evaluate histopathological changes.

Results:

Cd caused significant alterations in seminiferous tubules with varying effects on the patterns of spermatozoa production. These histopathological changes were significantly higher in the Cd group, compared to the control group.

Conclusion:

The Cd-induced stepwise spectrum changes included sloughing, disorganization, hypospermatogenesis, spermatic cell arrest, germ cell hypoplasia, Sertoli cell-only pattern, fibro-hyalinized seminiferous tubules, and calcification. Sertoli cells accumulated and created multinucleated giant cells in the seminiferous tubules during the atrophic process, which could be dependent upon Sertoli cells viability and function.

Ultra-acute exposure to cadmium does not impair whitefish sperm motility

Cadmium (Cd) exposure can impair the traits of aquatic animals associated with reproduction. In natural lakes Cd is typically detected at concentrations below 0.001 mg l^-1 . The authors investigated the impact of ultra-acute Cd exposure on sperm motility in European whitefish (Coregonus lavaretus). They activated sperm with water containing various nominal concentrations of Cd and recorded sperm motility parameters. Only the highest Cd concentration (500 mg l^-1 ) was associated with decreased sperm swimming velocity and increases in both the percentage of static cells and curvature of the sperm swimming trajectory. The results indicate that environmentally realistic concentrations of Cd during the sperm motility activation are not critically harmful to male C. lavaretus fertilization potential.

Exogenous Factors Affecting the Functional Integrity of Male Reproduction

Natural processes along with increased industrial production and the irresponsible behavior of mankind have resulted in environmental pollution. Environmental pollutants can be categorized based on their characteristics and appearance into the following groups: physical, biological, and chemical. Every single one of them represents a serious threat to the male reproductive tract despite the different modes of action. Male gonads and gametes are especially vulnerable to the effect of exogenous factors; therefore, they are considered a reliable indicator of environmental pollution. The impact of xenobiotics or radiation leads to an irreversible impairment of fertility displayed by histological changes, modulated androgen production, or compromised spermatozoa (or germ cells) quality. The present article reviews the exogenous threats, male reproductive system, the mode of action, and overall impact on the reproductive health of humans and animals.

Mercury-Induced Inhibition of Tyrosine Phosphorylation of Sperm Proteins and Altered Functional Dynamics of Buck Spermatozoa: an In Vitro Study

Present study was undertaken on buck spermatozoa to investigate the effect of mercuric chloride on functional dynamics of buck spermatozoa. Four different concentrations (0.031, 0.125, 0.25 and 1.25 μg/mL) of mercuric chloride, which were 1/40^th, 1/10^th, 1/5^th and equivalent to the LC₅₀ value of HgCl₂, were selected for studying their effect following in vitro exposure for 15 min and 3 h. Exposure of spermatozoa to 0.031 μg/mL mercuric chloride for 3 h resulted in significant (p < 0.05) decrease in sperm motility, sperm having intact membrane, intact acrosome and high mitochondrial trans-membrane potential. However, following exposure to higher concentrations (0.25, 1.25 μg/mL), similar results were observed even after 15 min of exposure. HgCl₂ significantly (p < 0.05) increased the levels of malondialdehyde and reactive oxygen species and significantly (p < 0.05) decreased total antioxidant capacity and superoxide dismutase activity in spermatozoa within 15 min of exposure. Mercuric chloride-treated spermatozoa did not show capacitation, rather exhibited spontaneous acrosome reaction along with significant increase in intracellular Ca²⁺ and cAMP levels. Immuno-blotting of semen samples of control and 0.031 μg/mL mercury-treated groups showed low intensity bands of p55, p70, p80, p105 and p190 kDa tyrosine phosphorylation proteins while higher concentration-treated groups showed no such bands. Our findings evidently suggest that mercuric chloride even at 0.031 μg/mL adversely affected sperm functions, inhibited tyrosine phosphorylation proteins and capacitation due to oxidative stress. Spontaneous acrosome reaction (AR) in mercury-treated spermatozoa may possibly be due to increase in intracellular Ca²⁺ and cAMP levels, and capacitation failure may be due to inhibition of tyrosine phosphorylation of proteins.

The Effect of Resorcinol on Bovine Spermatozoa Parameters in Vitro

The goal of this study was to observe the effect of resorcinol on motility, viability and morphology of bovine spermatozoa. The semen was used from six randomly chosen breeding bulls. Ejaculate was diluted by different solutions of resorcinol in 1:40 ratio. Samples were divided into 7 groups with different concentrations of resorcinol (Control, RES1 - 4 mg/ml, RES2 - 2 mg/ml, RES3 - 1 mg/ml, RES4 - 0.5 mg/ml, RES5 - 0.25 mg/ml and RES6 - 0.125 mg/ml). Motility of spermatozoa was detected using CASA method at temperature of 37 °C in time periods 0, 1, 2, 3, 4 hours from the start of the experiment. Significant motility differences between all groups except control and RES6 with difference of 5.58 %, as well as between RES1 and RES2 groups with difference of 2.17 % were found. Progressive motility had the same significant differences. Spermatozoa viability (MTT test) decreased compared to control in all experimental groups during the entire duration of experiment. Observing morphologically changed spermatozoa, no significant changes were observed and a higher percentage of spermatozoa with separated flagellum in all experimental resorcinol groups compared to control were detected. Also, increased number of spermatozoa with broken flagellum, acrosomal changes and other morphological forms in the group with the highest concentration of resorcinol (RES1) were found. Results of our study clearly show negative effects on motility parameters of spermatozoa which depend on concentration, cultivation temperature and time period.

Comparison of the deleterious effects of yaji and cadmium chloride on testicular physiomorphological and oxidative stress status: The gonadoprotective effects of an omega-3 fatty acid

Objective

This study investigated testicular oxidative stress status and physiomorphological function in Wistar rats fed with yaji and cadmium chloride (CdCl₂).

Methods

Sixty male albino Wistar rats (12 per group) were randomly assigned to five groups: group I (control), group II (300 mg/kg.bw of yaji), group III (500 mg/kg.bw of yaji), group IV (2.5 mg/kg.bw of CdCl₂), and group V (2.5 mg/kg.bw of yaji+4 mg/kg.bw omega-3). Each group was evenly subdivided into two subgroups and treatment was administered for 14 days and 42 days, respectively. Semen quality (sperm count, progressive motility, normal morphology, and gonadosomatic index), hormones (testosterone, follicle-stimulating hormone, and luteinizing hormone), testicular oxidative stress markers (superoxide dismutase, catalase, glutathione peroxidase, and malonaldehyde) and testicular histomorphological features were examined.

Results

Yaji caused significant (p< 0.05) dose- and duration-dependent reductions in semen quality, the gonadosomatic index, testosterone, follicle-stimulating hormone, and luteinizing hormone. Yaji also caused significant (p< 0.05) dose- and duration-dependent decreases in superoxide dismutase, catalase, and glutathione peroxidase activity, as well as increased testicular malonaldehyde levels. Yaji induced distortions in the testicular histological architecture. CdCl₂ damaged testicular function by significantly (p< 0.05) reducing semen quality, reproductive hormone levels, and oxidative stress markers in albino Wistar rats. CdCl₂ also altered the histology of the testis.

Conclusion

This study shows that yaji sauce has similar anti-fertility effects to those of CdCl₂, as it adversely interferes with male reproduction by impairing oxidative stress markers and the function and morphological features of the testis.

Coenzyme Q10 ameliorates cadmium induced reproductive toxicity in male rats

This study aimed at investigating the protective role of CoQ10 against cadmium (Cd)-induced reproductive toxicity in male rats. Adult male Wistar rats were exposed to an acute dose of Cd (25 mg/kg bwt; Cd group), Cd+CoQ10 (25 mg/kg bwt Cd+10 mg CoQ10; Cd-Q10 group) and distilled water (control) in vivo for 15 consecutive days and semen quality was assessed. A significant reduction was noted in sperm concentration, progressive motility, morphology and DNA integrity in both Cd- and Cd-Q10 groups in comparison to control indicating Cd-induced testicular lipid per oxidation (LPO) and decline in indigenous antioxidant defense system as measured by total antioxidant capacity (TAC) (p<0.05). However, simultaneous co-administration of CoQ10 along with Cd (Cd-Q10 group) was able to improve sperm concentration, motility, progressive motility, morphology, DNA integrity, and testicular TAC as well as lower LPO compared to Cd group (p<0.05). Results indicate that used dose of CoQ10 is capable of moderately ameliorating reproductive toxicity of Cd by improving semen quality and reducing testicular oxidative stress.

Presence of cadmium residues in muscle, liver and kidney of Bubalus bubalis and histological evidence

Cadmium (Cd) concentrations were evaluated in the samples of kidney, liver and muscle of sixty-six buffaloes regularly slaughtered. Forty were raised in Campania, in the territory between the province of Naples and Caserta and twenty-six were bred in Apulia, in the province of Bari. Two aliquots were prepared for the renal and hepatic samples: one intended for the chemical analysis and the other one intended for histological investigations. Muscle samples were the subject of purely chemical investigation. In the group of forty animals raised in the Campania region, the limits imposed by EC Reg. 1881/2006 and EC Reg. 488/2014 were exceeded in three renal samples, which showed values of 1.53, 1.22 and 1.1 mg/kg respectively; in three hepatic samples, which presented values of 0.72, 0.64 and 0.61 mg/kg, and in five muscle samples, with values of 0.16, 0.16, 0.09, 0.08 and 0.07, respectively. On the other hand, in the group of animals raised and slaughtered in the province of Bari, none of the twenty-six samples examined exceeded the limits imposed by the European regulations. The histological analysis showed typical, but not pathognomonic lesions in the renal samples from the animals raised in the provinces of Naples and Caserta. The levels of Cd contamination found in the samples examined suggest that it would be correct to exclude from the human consumption, as it happens for the equines, the kidney and the liver, especially from the animals raised in some geographical areas with a high rate of pollution.

Exposure to ambient fine particulate matter and semen quality in Taiwan

Objectives

Environmental exposure to chemicals has been considered a potential factor contributing to deteriorated semen quality. However, previous literature on exposure to air pollution and semen quality is inconsistent. We therefore investigated the health effects of short-term and long-term exposure to fine particulate matter (PM_2.5) on semen quality in Taiwanese men from the general population.

Methods

A cross-sectional study was conducted among 6475 male participants aged 15–49 years who participated in a standard medical examination programme in Taiwan between 2001 and 2014. Semen quality was assessed according to the WHO 1999 guidelines, including sperm concentration, total motility, progressive motility and morphology. Three-month and 2-year average PM_2.5 concentrations were estimated at each participant’s address using a spatiotemporal model based on satellite-derived aerosol optical depth data. Multivariable linear and logistic regressions were used to examine the associations between PM_2.5 and semen quality.

Results

A robust association was observed between exposure to PM_2.5 and decreased normal morphology. Every increment of 5 µg/m³ in 2-year average PM_2.5 was significantly associated with a decrease of 1.29% in sperm normal morphology and a 26% increased risk of having the bottom 10% of sperm normal morphology, after adjusting for a wide range of potential confounders (p<0.001). On the other hand, an increment of 5 µg/m³ in 2-year average PM_2.5 was associated with an increase of 1.03×10⁶/mL in sperm concentration and a 10% decreased risk of being the bottom 10% of sperm concentration (both p<0.001). Similar results were found for 3-month PM_2.5.

Conclusions

Exposure to ambient PM_2.5 air pollution is associated with a lower level of sperm normal morphology and a higher level of sperm concentration.

The environment and male reproduction: The effect of cadmium exposure on reproductive function and its implication in fertility

Cadmium is an environmental pollutant known as endocrine disruptor. Testis is particularly susceptible to cadmium, and testis injury occurs at high but even low levels of exposure. Cadmium reproductive toxicity is mediated by multiple mechanisms, including structural damage to testis vasculature and blood-testis barrier, inflammation, cytotoxicity on Sertoli and Leydig cells, oxidative stress mainly by means of mimicry and interference with essential ions, apoptosis, interference with selected signaling pathways and epigenetic regulation of genes involved in the regulation of reproductive function, and disturbance of the hypothalamus-pituitary-gonadal axis. The current review outlines epidemiological observational findings from environmental and occupational exposure in humans, and reports experimental studies in humans and animals. Lastly, a focus on the pathogenetic mechanisms of cadmium toxicity and on the specific mechanisms of cadmium sensitivity and resistance, particularly assessed in animal models, is included. Despite convincing experimental findings in animals and supporting evidences in humans identifying cadmium as reproductive toxicant, observational findings are controversial, suffering from heterogeneity of study design and pattern of exposure, and from co-exposure to multiple pollutants.

Effect of separate and combined exposure of selenium and diazinon on rat sperm motility by computer assisted semen analysis

Effects of selenium (Se) and diazinon (DZN) on sperm motility parameters in rats were investigated. Male rats received a separate dose of Se (2mgkg^-1 b.w., intraperitoneally, 5mgL^-1, per os in drinking water), diazinon (20mgkg^-1 b.w., intraperitoneally, 40mgL^-1, per os in drinking water), and in combination (Se+DZN) with the same dosage as in the separate administration. 36h an intraperitoneal (i.p.) and after 90days of per oral (p.o.) exposure, thirteen parameters of sperm motility were evaluated using a Computer Assisted Sperm Analyzer (CASA). Almost all the evaluated sperm motility parameters significantly decreased in Se p.o. exposed groups. In the Se i.p. group decrease was noted only in beat cross frequency (BCF) and progressive motility. Significant decline in the sperm motility, progressive motility, BCF and increase in amplitude of lateral head displacement (ALH) were recorded after DZN i.p. administration. In DZN p.o. group, significant increase in ALH, velocity average path (VAP) and curvilinear velocity (VCL) but decrease in progressive motility and BCF was detected. Se+DZN i.p. administration caused a significant decrease in motility, progressive motility and BCF. Per oral administration of Se+DZN decreased all motility parameters except LIN, WOB and ALH. Sperm abnormalities increased in all experimental conditions. Se and DZN negatively affected sperm structure and function in separate doses or in combination. No protective effect of Se was observed.

Tyrosine phosphorylation of dihydrolipoamide dehydrogenase as a potential cadmium target and its inhibitory role in regulating mouse sperm motility

Cadmium (Cd) is reported to reduce sperm motility and functions. However, the molecular mechanisms of Cd-induced toxicity remain largely unknown, presenting a major knowledge gap in research on reproductive toxicology. In the present study, we identified a candidate protein, dihydrolipoamide dehydrogenase (DLD), which is a post-pyruvate metabolic enzyme, exhibiting tyrosine phosphorylation in mouse sperm exposed to Cd both in vivo and in vitro. Immunoprecipitation assay demonstrated DLD was phosphorylated in tyrosine residues without altered expression after Cd treatment, which further confirmed our identified result. However, the tyrosine phosphorylation of DLD did not participate in mouse sperm capacitation and Bovine Serum Albumin (BSA) effectively prevented the tyrosine phosphorylation of DLD. Moreover, Cd-induced tyrosine phosphorylation of DLD lowered its dehydrogenase activity and meanwhile, Nicotinamide Adenine Dinucleotide Hydrogen (NADH) content, Adenosine Triphosphate (ATP) production and sperm motility were all inhibited by Cd. Interestingly, when the tyrosine phosphorylation of DLD was blocked by BSA, the decrease of DLD activity, NADH and ATP content as well as sperm motility was also suppressed simultaneously. These results suggested that Cd-induced tyrosine phosphorylation of DLD inhibited its activity and thus suppressed the tricarboxylic acid (TCA) cycle, which resulted in the reduction of NADH and hence the ATP production generated through oxidative phosphorylation (OPHOXS). Taken together, our results revealed that Cd induced DLD tyrosine phosphorylation, in response to regulate TCA metabolic pathway, which reduced ATP levels and these negative effects led to decreased sperm motility. This study provided new understanding of the mechanisms contributing to the harmful effects of Cd on the motility and function of spermatozoa.

Cadmium inhibits mouse sperm motility through inducing tyrosine phosphorylation in a specific subset of proteins

Cadmium (Cd) has been reported to impair male fertility, primarily by disrupting sperm motility, but the underlying molecular mechanism remains unclear. Here we investigated the effects of Cd on sperm motility, tyrosine phosphorylation, AMP-activated protein kinase (AMPK) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity, and ATP levels in vitro. Our results demonstrated that Cd inhibited sperm motility, GAPDH activity, AMPK activity and ATP production, and induced tyrosine phosphorylation of 55-57KDa proteins. Importantly, all the parameters affected by Cd were restored to normal levels when incubated with 10μM Cd in the presence of 30μM ethylene diamine tetraacetic acid (EDTA). Interestingly, changes of tyrosine phosphorylation levels of 55-57KDa proteins are completely contrary to that of other parameters. These results suggest that Cd-induced tyrosine phosphorylation of 55-57KDa proteins might act as an engine to block intracellular energy metabolism and thus decrease sperm motility.

Levels of metals in kidney, liver and muscle tissue and their relation to the occurrence of parasites in the red fox in the Lower Silesian Forest in Europe

Together with the occurrence of parasites, increased concentrations of xenobiotics, to which scavengers are greatly exposed, may significantly influence the physiology of red foxes. It is also suspected that these two factors interact. The accumulation of various metals (Ca, Cd, Cu, Fe, Hg, K, Mg, Ni, Pb, Zn) in kidney, liver and muscle tissue was investigated, as well as the occurrence of parasites, and the potential link to the presence of metals. Generally speaking, neither sex nor age influenced these concentrations. K, Mg and Fe were found in the highest concentrations and Hg was found in the lowest. Various relationships between the concentrations of metals were observed in the tissues. 34% of the specimens studied were hosts to parasites. No clear, significant connection between the concentrations and the occurrence of parasites was noted, but the discernible trend confirmed by the logistic regression, needs further study.

Endocrine disruptive effects of cadmium on steroidogenesis: human adrenocortical carcinoma cell line NCI-H295R as a cellular model for reproductive toxicity testing

Cadmium (Cd) is a known endocrine disruptor with the ability to affect the production of hormones involved in the regulation of reproductive processes. In this study human adrenocortical carcinoma cell line NCI-H295R was used as an in vitro biological model to study the effect of cadmium (CdCl2) on steroidogenesis. The cell cultures were exposed to different concentrations of CdCl2 (1.90, 3.90, 7.80, 15.60, 31.20 and 62.50 μM) and compared to control (medium without CdCl2). Cell viability was measured by the metabolic activity (MTT) assay for estimation of mitochondria structural integrity. Quantification of sexual steroid production directly from aliquots of the medium was performed by enzyme linked immunosorbent assay (ELISA). Following 48 h culture of the cells in the presence of CdCl2 a concentration-dependent depletion in progesterone production was observed at the lower concentrations of CdCl2. The lowest amount of progesterone was significantly detected in groups with the higher doses (≥ 31.20 μM) of CdCl2, which elicited significant (P < 0.01) cytotoxic action, too. Cadmium decreased testosterone release in the whole applied range even at the lower concentration of CdCl2. The release of 17β-estradiol decreased as well, but the decline was less pronounced compared to decrease of progesterone and testosterone. The cytotoxic effect was significantly (P < 0.01) detected at all concentrations of CdCl2 (1.90-62.50 μM) used in the study. However, the cell viability remained relatively high (>75%) up to 7.80 μM of CdCl2 and significantly (P < 0.01) decreased at 15.60 μM and higher concentrations of CdCl2. These results suggest that cadmium has endocrine disruptive effects on sexual steroid synthesis even at very low concentrations.

Effect of mercury on porcine ovarian granulosa cells in vitro

The objective of this in vitro study was to examine dose-dependent changes in the secretion activity [progesterone (P4) and insulin-like growth factor-I (IGF-I)] of porcine ovarian granulosa cells after experimental mercury (Hg) administration, including its apoptotic potential so as to ascertain the possible involvement of Hg in steroidogenesis. Ovarian granulosa cells were incubated with mercuric chloride [mercury (II) chloride or HgCl2] at the doses 50-250 μg mL(-1) for 18 h and compared with control group without Hg addition. Release of P4 and IGF-I by ovarian granulosa cells was assessed by RIA and apoptosis by TUNEL assay. Observations show that P4 release by granulosa cells was significantly (P < 0.05) inhibited at all the doses, while IGF-I release was not affected at any of the doses used, although a decreasing trend in the release of IGF-I was noted in comparison to control. An increasing trend of apoptosis of granulosa cells was noted, the difference being significant (P < 0.05) only at the dose 130 μg mL(-1) HgCl2, in comparison to control. Obtained data suggest a direct effect of Hg on the release of steroid hormone progesterone but not growth factor IGF-I, and a dose-dependent effect on apoptosis of porcine ovarian granulosa cells. Results indicate the interference of Hg in the pathways of steroidogenesis and apoptosis of porcine ovarian granulosa cells.

Dose- and time-dependent effects of bisphenol A on bovine spermatozoa in vitro

The present study was to evaluate the effect of bisphenol A (BPA) at the doses 1, 10, 100 and 200 µg mL(-1) on the bovine spermatozoa motility, viability and production of superoxide radical. The CASA system was used to determine the spermatozoa motility. The initial motility showed the significant differences (P < 0.001) between the groups higher than 100 µg BPA mL(-1) and the control group. Evaluation of the spermatozoa motility after 6 h of cultivation at the doses > 10 µg BPA mL(-1) was found to decrease motility significantly. After 24 h it was observed that the doses < 10 µg BPA mL(-1) statistically increased motility, while the doses > 100 µg BPA mL(-1) significantly decreased motility in comparison to control. The viability of spermatozoa as detected by the MTT assay decreased in all experimental groups, but significant differences were noted only at the highest doses of BPA after 24 h of in vitro cultivation. The intracellular superoxide production was observed by the NBT test after 24 h of BPA exposure. The results indicated that in all experimental groups the amount of superoxide increased as compared to the control group; significant changes were observed at the doses > 100 µg BPA mL(-1). In conclusion, the results from our experiments suggest the negative effects of BPA at the highest doses used on motility and viability of bovine spermatozoa and production of superoxide radical.

Blood concentration of copper, cadmium, zinc and lead in horses and its relation to hematological and biochemical parameters

Environmental pollution results in serious health hazards to animals and blood analysis serves as a good alternative for health status assessment. The target of this study was to analyze the concentration of selected metals in equine blood, to analyze the blood parameters and to find possible correlations. Blood samples were collected from the vena jugularis of healthy adult horses. The highest concentration of all elements was found in whole blood (Cu 3.84 ± 0.90 mg L(-1); Cd = 0.81 ± 0.90 mg L(-1); Zn 26.67 ± 14.12 mg L(-1); Pb 9.33 ± 5.76 mg L(-1)). Higher concentrations of copper, cadmium, zinc and lead were detected in blood clots compared to blood sera (44.04%). A similar tendency was found for cadmium (50%), zinc (13.08%) and lead (46.02%), which showed generally higher concentrations in blood clots (cells). Correlation analysis proved some relations between analyzed elements. In blood clots there is a strong positive correlation between Cd - Pb (r = 0.93) and Zn - Pb (r = 0.71) was detected. For biochemical and hematological parameters mainly medium correlations were detected. Obtained results prove different correlations of analyzed elements in blood components as well as the effect on parameters of blood biochemical and hematological profiles.

Cobalt-induced hormonal and intracellular alterations in rat ovarian fragments in vitro

The objective of this in vitro study was to examine dose-dependent changes in the secretion activity (progesterone, 17β-estradiol and insulin-like growth factor-I) of rat ovarian fragments after experimental cobalt (Co) administration including the apoptotic potential of Co on rat ovarian fragments by evaluating the expression of apoptotic markers Bax and caspase-3. Ovarian fragments were incubated with cobalt sulphate (CoSO4.7H2O) at the doses 90, 170, 330 and 500 μg.mL(-1) for 24 h and compared with control group without Co addition. Release of progesterone (P4) 17β-estradiol and insulin-like growth factor-I (IGF-I) by ovarian fragments was assessed by RIA, expression of Bax and caspase-3 by SDS-PAGE and Western blotting. Observations show that P4 release by ovarian fragments was significantly (P < 0.05) inhibited after cobalt sulphate addition at higher doses 170-500 μg.mL(-1) used in the study in comparison to control. However, cobalt sulphate addition did not cause any significant change in the release of 17β-estradiol by ovarian fragments at all the doses used in the study (90-500 μg.mL(-1)) in comparison to control. On the contrary, IGF-I release by ovarian fragments was significantly (P < 0.05) stimulated after cobalt sulphate addition at the lowest dose 90 μg.mL(-1) in comparison to control, while other doses did not cause any significant change. Also, addition of cobalt sulphate decreased the expression of both the apoptotic peptides Bax and caspase-3 at the higher doses 170, 330 and 500 μg.mL(-1), but not at the lowest dose 90 μg.mL(-1) used in the study. Obtained results suggest Co induced (1) inhibition in secretion of steroid hormone progesterone, (2) dose-dependent increase in the release of growth factor IGF-I, and (3) decrease in the expression of markers of apoptosis (Bax and caspase-3) of rat ovarian fragments.

Accumulation of zinc, nickel, lead and cadmium in some organs of rabbits after dietary nickel and zinc inclusion

This study reports the effect of dietary nickel (Ni) and a combination of Ni and zinc (Zn) on the accumulation of lead (Pb), cadmium (Cd), Ni and Zn in muscles, liver and kidneys of rabbits. Female rabbits (Oryctolagus cuniculus) of experimental groups were fed a granular mixture with addition of various concentrations of Ni or Ni+Zn (E1 - 17.5 g NiCl(2) per 100 kg of feed mixture, group E2 - 35.0 g NiCl(2) per 100 kg of feed mixture, group E3 - 17.5 g NiCl(2) per 100 kg of feed mixture and 30 g ZnCl(2) per 100 kg of feed mixture, group E4 - 35.0 g NiCl(2) per 100 kg of feed mixture and 30 g ZnCl(2) per 100 kg of feed mixture). Group C without inclusion of Ni or Zn served as control. After the 90-day experimental period biological material (liver, kidney, musculus longissimus dorsi, musculus biceps femoris) was taken from the animals. Samples were analyzed by the AAS method. Ni added to the FM caused an increase in Cd concentration in the kidneys of the rabbits, significantly in the E3 group in comparison with the control group. In the liver an insignificant decrease of Cd concentration was found. Zn addition in the amount of 30 g to the diet caused an increase of Cd level in the kidney as well as in the liver. Ni and Zn treatment caused a significant decrease of Pb accumulation in the m. longissimus dorsi of rabbits. This study indicates that dietary inclusion of Ni and Zn caused specific interactions among the observed metals.