Concentration of trace elements in human semen and relation to spermatozoa quality

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.

Determination of Electrolytes and Trace Elements in Biological Samples from Patients with Altered Semen Parameters: a Correlational Analysis

The effects of important nutrients such as calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se), and zinc (Zn) have been investigated in relation to male fertility due to their roles in proper spermatogenesis, sperm maturation, motility, and optimal sperm function. An imbalance between these elements has been associated with several pathologic conditions and male reproductive issues. The purpose of this study was to determine the essential trace and electrolytes elements, such as Ca, Cu, Fe, Mg, Se, and Zn, in human biological samples (blood, serum, and semen) from patients with male infertility. This study used correlational analysis to determine the potential associations between these elements and male fertility. Imbalances in these elements have been linked to various pathological conditions and male reproductive issues. One hundred eighty referent male adults and two hundred twenty-nine patients diagnosed with subtypes of infertility were included in the study, divided into two age groups. Acid digestion was controlled using a microwave oven, and the essential trace elements and electrolytes in the oxidized biological samples were determined using atomic absorption spectrometry. Certified reference materials of blood and serum were used to validate the accuracy of the methodology. The results showed that the concentrations of Ca, Cu, Fe, Mg, Se, and Zn in the blood, serum, and seminal plasma of male adults in all age groups were higher than those in patients with different infertility phenotypes. Essential element deficiency in all biological fluid samples may significantly negatively affect human reproductive health and lead to male infertility. Through a multidimensional approach, our study sought to unravel the intricate biochemical signatures associated with OAT, providing insights that may shape the landscape of diagnostic and therapeutic strategies for male reproductive health.

A comprehensive study into false positive rates for 'other' biological samples using common presumptive testing methods

The identification of biological fluids or materials in forensic samples is a key requirement in forensic science that relies on chemical and biological based tests, most of which exhibit false positivity. When reporting results from such tests, Forensic Scientists use words such as probable, possible, and likely, without always being able to provide robust support for these conclusions. In collating information about false positive rates for a number of these tests, we found limited research into the cross reactions observed from 'other' biological samples in commonly encountered case sample stains. By 'other' we mean biological fluids or materials that are not the primary target of the presumptive test being used. Here we carry out a specificity study to fill gaps in the literature for a number of the presumptive chemical, biological and immunochromatographic tests used to presumptively screen for blood, semen and saliva. The tests selected for this study are the widely used tests: Luminol, TMB/Combur³ Test® E, Kastle-Meyer (KM), RSID™ - Blood, ABAcard® HemaTrace®, Acid Phosphatase (AP), ABAcard® p30, RSID™ - Semen, Phadebas® 'Tube' Test, Phadebas® 'Press' Test, and RSID™ - Saliva tests. Specificity for each of these was tested in known samples, from volunteers, of blood, semen, saliva, urine, sweat, vaginal material, faeces and breast milk, and then false positive rates were determined.

Associations of Semen Quality with Seminal Non-essential Heavy Metals in Males from the Canary Islands

Semen quality and levels of non-essential metals such as strontium (Sr), aluminum (Al), lead (Pb), nickel (Ni), and vanadium (V) were measured. Metals were determined by ICP-OES (inductively coupled plasma - optical emission spectrometry) in semen samples from 102 men who were recruited in a Reproduction Unit in the Canary Islands. The presence of each metal was as follows: Sr: 56.9%, Al: 73.5%, Pb: 45.1%, Ni: 15.7%, and V: 79.4% of the samples. No significant differences were found in the relationship between the spermiogram, the sperm motility, and the concentration of spermatozoa levels of non-essential metals. It is noteworthy that Ni levels tend to be lower in patients with oligozoospermia (t (46.4) = 1.84; p = 0.070). Between lifestyle and non-essential metals, there was a significant relationship between the level of occupational exposure to metals and Ni (χ²(2) = 13.91; p = 0.001). We did not find significant differences in non-essential seminal metal content and smoking status but, there were differences between drinkers and the concentration of V in semen (t (100) = -1.99; p = 0.050). The occupational exposure to metals and place of residence have effects on Al and V levels in semen. Regarding obesity, significant differences were found in Pb levels (t (18.0) = 2.34; p = 0.031). Obese patients have a lower Pb level, and the percentage of progressive sperm motility was lower in obese men (t (98) = 2.14; p = 0.035). The detection of metals in semen opens a new field in the study of male infertility with the possibility of performing treatments aimed at correcting these possible anomalies.

Impact of Heavy Metals on Human Male Fertility-An Overview

Heavy metals are endocrine disruptors which interfere with processes mediated by endogenous hormones of the organism, negatively affecting endocrine functions. Some studies have correlated heavy metal exposure with male infertility. However, the number of studies conducted on humans are limited. Therefore, the aim of this study is to summarize the current knowledge on how heavy metals influence human male fertility. Hence, three distinct databases were consulted—PubMed, Scopus and Web of Science—using single keywords and combinations of them. The total number of identified articles was 636. Nevertheless, by using the inclusion and exclusion criteria, 144 articles were finally included in this work. Results display that the development of adequate instruments for heavy metal assessment may play an important function in human male fertility diagnosis and treatment. Furthermore, clinical trials could be useful to confirm the role of heavy metals in human male fertility diagnosis. Overall, further research is required to fully understand the molecular and cellular basis of the influence of environmental and occupational exposure to heavy metals on human male infertility and reproductive outcomes.

Exposure to multiple metals/metalloids and human semen quality: A cross-sectional study

BACKGROUND

Exposure to metals/metalloids, including essential and nonessential elements, has been associated to male reproductive health in animals. However, findings from human studies are inconsistent.

OBJECTIVES

To investigate the impact of exposure to multiple metals/metalloids at environmental levels on the conventional human semen-quality parameters.

MATERIALS AND METHODS

Men living in rural or industrial areas were recruited by personalized letters. No exclusion criteria were applied. Each man provided one semen sample and one blood sample. We analyzed the semen sample both to determine conventional sperm parameters (concentration, progressive motility and normal forms) and to quantify lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), vanadium (V) and selenium (Se) levels. The levels of these metals/metalloids were also quantified in venous blood and spermatozoa samples. Associations between the blood/seminal plasma metal/metalloid levels and semen quality parameters were assessed using confounder adjusted logistic regression models. Correlation and interactions between blood/seminal plasma and semen metal/metalloid levels were investigated using the Spearman's correlation.

RESULTS

We found a positive association of seminal plasma cadmium level with lower Total count (OR = 4.48, 95%CI 0.25-80); whereas lead (OR = 4.51, 95%CI 0.86-23) and cadmium (OR = 3.45, 95%CI 0.77-16) seminal plasma levels had a positive association with progressive sperm motility. Overall, these associations remained suggestive after adjustment, though statistically unstable risks. Finally, we found weak interactions between beneficial effects of Se and detrimental ones only for Cd and Pb blood level on sperm concentration, total sperm count and progressive sperm motility.

CONCLUSIONS

Our findings suggest that environmental exposure to Pb and Cd contributes to a decline in human semen quality, whereas Se can have beneficial effects. Measurements of metals/metalloids in the seminal fluid may be more predictable of semen quality than conventional blood measurements.

Collapsed mitochondrial cristae in goat spermatozoa due to mercury result in lethality and compromised motility along with altered kinematic patterns

Earlier we have reported mercury-induced alterations in functional dynamics of buck spermatozoa through free radicals-mediated oxidative stress and spontaneous acrosome reaction. Based on our earlier findings, we aimed to investigate the effect of mercury exposure on motility, kinematic patterns, DNA damage, apoptosis and ultra-structural alterations in goat spermatozoa following in vitro exposure to different concentrations (0.031-1.25 µg/ml) of mercuric chloride for 15 min and 3 h. Following exposure of sperm cells to 0.031 µg/ml of mercuric chloride for 3 h, livability and motility of sperms was significantly reduced along with altered kinematic patterns, significant increase in per cent necrotic sperm cells and number of cells showing DNA damage; and this effect was dose- and time-dependent. Contrary to up-regulation of Bax gene after 3 h in control group, there was significant increase in expression of Bcl-2 in mercury-treated groups. Transmission electron microscopy studies revealed rifts and nicks in plasma and acrosomal membrane, mitochondrial sheath, and collapsed mitochondria with loss of helical organization of mitochondria in the middle piece of spermatozoa. Our findings evidently suggest that mercury induces necrosis instead of apoptosis and targets the membrane, acrosome, mid piece of sperms; and the damage to mitochondria seems to be responsible for alterations in functional and kinematic attributes of spermatozoa.

Detrimental effects of long-term exposure to heavy metals on histology, size and trace elements of testes and sperm parameters in Kermani Sheep

Exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized as a cause of declining sheep reproductive efficiency. Understanding the long-term effects of EDCs such as heavy metals on reproductive health requires investigation in 'real life' of sheep that are reared in industrial areas. The aim of this study was to evaluate the effect of long-term exposure of Kermani rams to high levels of environmental heavy metals probably emitted from a copper smelter at KhatoonAbad in ShahreBabak, Kerman province. Testicular characteristics were determined in randomly-selected rams (3-4 years old) at 4 directions (south, north, east, and west) and 4 distances (10, 20, 30, and 40 km) from the smelter. Testicular trace element contents, size, serum testosterone, histological attributes and seminal characteristics, except semen volume, were affected by both the direction and the distance from the smelter (P < 0.05). Testicular contents of Pb, Cd, Cr, and Ni, and sperm abnormalities were higher at 10 km south from the smelter and lower at 40 km west. Other parameters were higher at 40 km west and lower at 10 km south. Interestingly, the testicular contents of Cu at 10 km south were lower and associated with higher sperm abnormalities in the rams reared closer to the smelter. The highest weight, length and circumference of the testis were found at 40 km west. The lowest concentration of testosterone was observed at 10 km south, being 92.6% lower than the highest values obtained at 40 km west. The diameter of seminiferous tubules and epithelial height at 10 km south were 8.9% and 27.5% lower than the highest values obtained at 40 km west. A positive correlation between Pb, Cd, Cr and Ni contents in the testis with sperm abnormalities, and a negative correlation between these elements with the other parameters were found. It was concluded that long-term exposure to heavy metals might have been a cause of decreased fertility in rams and probably other living species in this region.

Effects of Cadmium, Lead, and Mercury on the Structure and Function of Reproductive Organs

Reproductive organs are essential not only for the life of an individual but also for the survival and development of the species. The response of reproductive organs to toxic substances differs from that of other target organs, and they may serve as an ideal “barometer” for the deleterious effects of environmental pollution on animal and human health. The incidence of infertility, cancers, and associated maladies has increased in the last fifty years or more, while various anthropogenic activities have released into the environment numerous toxic substances, including cadmium, lead, and mercury. Data from epidemiological studies suggested that environmental exposure to cadmium, lead, and mercury may have produced reproductive and developmental toxicity. The present review focused on experimental studies using rats, mice, avian, and rabbits to demonstrate unambiguously effects of cadmium, lead, or mercury on the structure and function of reproductive organs. In addition, relevant human studies are discussed. The experimental studies reviewed have indicated that the testis and ovary are particularly sensitive to cadmium, lead, and mercury because these organs are distinguished by an intense cellular activity, where vital processes of spermatogenesis, oogenesis, and folliculogenesis occur. In ovaries, manifestation of toxicity induced by cadmium, lead, or mercury included decreased follicular growth, occurrence of follicular atresia, degeneration of the corpus luteum, and alterations in cycle. In testes, toxic effects following exposure to cadmium, lead, or mercury included alterations of seminiferous tubules, testicular stroma, and decrease of spermatozoa count, motility and viability, and aberrant spermatozoa morphology.

An overview on role of some trace elements in human reproductive health, sperm function and fertilization process

Human semen contains several trace elements such as calcium (Ca), copper (Cu), manganese (Mn), magnesium (Mg), zinc (Zn) and selenium (Se) which are necessary for reproductive health, normal spermatogenesis, sperm maturation, motility and capacitation, as well as normal sperm function. In this review, the potential role of these trace elements in male reproductive health, normal function of spermatozoa and fertility potency were considered. We selected and reviewed articles that considered crucial roles of trace elements in human sperm function and fertility. Ca is essential for sperm motility and its hyperactivation, sperm capacitation and acrosome reaction, as well as sperm chemotaxis. Sodium (Na) and potassium (K) are involved in sperm motility and capacitation. Mg is necessary for normal ejaculation, spermatogenesis and sperm motility. Zn is one of the most significant nutrients in human semen. Seminal deficiency of Zn can be associated with delayed testicular development, impaired spermatogenesis, deficiency of sex hormones, oxidative stress and inflammation, and apoptosis. Se is another significant element which has antioxidative properties and is essential for spermatogenesis and the maintenance of male fertility. Mn is a potent stimulator for sperm motility; however, increased level of seminal plasma Se can be toxic for sperm. Like Se, Cu has antioxidative properties and has a positive effect on sperm parameters. Decreased level of these trace elements can negatively affect human reproductive health, semen quality, sperm normal function and as the result, fertility potency in men. Measurement of these trace elements in men with idiopathic infertility is necessary.

The relationship between semen seminal plasma ions and sperm cell velocities of wild-caught longspine scraper, Capoeta trutta

In this study, semen seminal plasma contents and the motility of sperm cells were determined in Capoeta trutta via a computer-assisted sperm analysis system. In addition, we evaluated the relationship between semen seminal plasma ions and the velocities of sperm cells. Although the predominant ions were K ( 206.84 ± 20.61  mg L- 1 ) and Na ( 128.06 ± 23.82  mg L- 1 ) in the semen seminal plasma, Ca ( 14.05 ± 4.13  mg L- 1 ) and Mg ( 3.35 ± 0.44  mg L- 1 ) were not predominate according to our results. However, partially strong relationships between the curvilinear velocity value (VCL) and K (R 2 = 0.67 ; p < 0.05 ) were found, while it was moderate with Mg (R 2 = 0.48 ; p < 0.05 ). There was a weak relationship with Na (R 2 = 0.17 ; p < 0.05 ) and Ca (R 2 = 0.34 ; p < 0.05 ). In our results, while the trace metals were determined as Zn > Al > B > Li > Cu in semen seminal plasma, they are not correlated with sperm cell velocities. Finally, we hope that the present information on the motility parameters of Capoeta trutta in this paper will eventually help artificial insemination in reproduction practices.

Novel association between apoptotic sperm biomarkers with seminal biochemical parameters and acetylcholinesterase activity in patients with teratozoospermia

OBJECTIVE

We aimed to determine whether the dysfunction of physiological apoptosis and specific seminal biochemical parameters could be associated with male infertility and sperm morphological defects.

STUDY DESIGN

Ejaculated sperm samples from sixty patients with isolated teratozoospermia and thirty fertile donors were analyzed. The proportion of both viable and dead spermatozoa expressing activated caspases was detected by fluorescence microscopy through the use of different specific carboxyfluorescein-labeled caspase inhibitors FLICA. The different stages of apoptosis in human were qualitatively and quantitatively determined by using the AO/EB fluorescent staining method. The levels of the seminal biochemical parameters (acetylcholinesterase (AChE), lactate dehydrogenase (LDH), creatine phosphokinase (CK), iron (Fe), calcium (Ca), and phosphorus (P)) were evaluated spectrophotometrically.

RESULTS

Patients with teratozoospermia showed significantly higher proportions of dead and live spermatozoa with activated caspases and spermatozoa in the late stage of apoptosis when compared to controls. Among the different studied biochemical seminal parameters, the rates of acetylcholinesterase activity, creatine phosphokinase, iron, and calcium were significantly increased in the patient group. However, the rate of phosphorus was significantly decreased. Interestingly, significant relationships were found between the studied biochemical and apoptotic biomarkers and the rates of atypical sperm forms with the incidences of head, mid-piece, and tail abnormalities. Furthermore, positive correlations were found between P, AChE, Fe, CK, and LDH with apoptotic markers.

CONCLUSIONS

These results emphasize the impact of apoptosis in the pathophysiology of teratozoospermia and suggest that seminal biochemical disturbance may arise such damage.

Semen Uranium Concentrations in Depleted Uranium Exposed Gulf War Veterans: Correlations with Other Body Fluid Matrices

Environmental metal exposure, as well as dietary metals, may adversely affect semen quality even as others play an essential role in normal spermatogenesis and fertility. Measures of seminal fluid metals have therefore been of high interest in the last several decades but have shown inconsistent results in correlations with some semen quality parameters. As well, environmental metal measures across various body fluid matrices have not been consistently correlated contrary to what one might hypothesize based on a systemic body burden of metal. This may be due to the body fluid matrices assessed and to other differences in laboratory methods and sample preparation. Measures of uranium, a potentially toxic metal in humans, have not previously been reported in the semen of environmentally metal-exposed populations. We report here uranium seminal fluid results and the high correlation of uranium concentrations across several body fluid matrices in a cohort of military veterans exposed to depleted uranium in combat events during the Iraqi Gulf War. These results inform the risk communication conversation for exposed populations and broaden the public health assessments from various exposure scenarios.

Boar semen improvement through sperm capacitation management, with emphasis on zinc ion homeostasis

Critical to fertilization success, sperm capacitation within the female oviductal sperm reservoir endows mammalian spermatozoa with hyperactivated motility and capacity to fertilize. An elaborate cascade of signaling events during capacitation guides the redistribution of sperm plasma membrane seminolipid and cholesterol, Ca-influx and increases tyrosine phosphorylation to promote hyperactivated motility. Such events result in the remodeling of the sperm acrosome, increased fluidity and fusability of the plasma membrane, shedding of surface-adsorbed seminal plasma proteins that glue sperm heads to the oviductal epithelium and ultimately the release of hyperactivated spermatozoa from the oviductal sperm reservoir. Discovered recently, the capacitation-induced sperm zinc ion efflux and resultant zinc signatures are reflective of sperm capacitation status and fertilizing ability, inspiring the retrospection of zinc ion functions in the physiology and fertility of boar sperm and that of other species. This review also highlights the merit of the domestic boar as a biomedical model for spermatology and fertilization research. Relevant to the quest for better fertility management in the livestock industries, the benefits of zinc ion supplementation through nutrition and direct addition to extended semen are discussed in the context of artificial insemination (AI). Ideas are shared on future technologies for zinc management in AI doses and research on the sperm zinc-interacting proteome.

The association between iron, calcium, and oxidative stress in seminal plasma and sperm quality

The present study aimed to determine the level of iron and calcium in the seminal plasma of men with different fertility potentials and to examine its relationship with oxidative stress. Seventy-nine sub-fertile patients with asthenoteratozoospermia (AT), n 27; teratoleucozoospermia (TL), n 20; teratozoospermia (Terato), n 32; and 29 healthy donors were included. The ability of spermatozoa to produce reactive oxygen species (ROS) was evaluated by using nitroblue tetrazolium (NBT) staining. The lipid peroxidation end product, malondialdehyde (MDA), and the trace element levels (iron and calcium) were measured spectrophotometrically. Iron and calcium concentrations in seminal plasma of the patient groups were significantly more elevated than the normal group. Nevertheless, both calcium and iron showed strong negative correlations with the total sperm motility and normal sperm morphology, but only iron was positively and significantly associated with multiple anomalies index and seminal leucocyte concentration. On the other hand, the rates of MDA and ROS production in semen were significantly higher in the three abnormal groups than in controls. These two oxidative stress biomarkers were significantly associated with the percentage of atypical forms in semen. However, only semen ROS level was significantly associated with the decreased sperm motility and the sperm leucocytes concentration. Meanwhile, there are positive correlations between seminal iron and calcium content and the studied oxidative stress biomarkers. Oxidative stress and trace element excess are implicated in low sperm quality. Iron and calcium might be the mediators of the effects of oxidative damage and induces lipid peroxidation.

Serum and Seminal Plasma Element Concentrations in Relation to Semen Quality in Duroc Boars

Element concentrations in serum and seminal plasma were studied in Duroc boars with different semen quality characteristics. Based on the utilization rate of 2174 ejaculates from June to August in 2016, a total of 166 Duroc boars were allocated into three groups: low utilization rate group (LG, 0 to 60% utilization rate), medium utilization rate group (MG, 60 to 80%), and high utilization rate group (HG, 80 to 100%). Serum and seminal plasma samples were collected, and element levels were analyzed using inductively coupled plasma mass spectrometry. The results showed that LG boars had higher concentrations of serum copper and seminal plasma cadmium compared with MG and HG boars (P < 0.05), and serum copper and seminal plasma cadmium were negatively correlated with sperm motility, while positively correlated with the abnormal sperm rate. We observed the abnormal sperm rate increased by approximately 4.53% with serum copper increasing from 1.63 to 2.44 mg/L, while sperm motility decreased by approximately 2.85% with seminal plasma cadmium increasing from 0 to 0.82 μg/L. Moreover, serum iron and manganese levels in the LG group were significantly reduced compared with the HG boars (P < 0.05), and the two elements were negatively correlated with the abnormal sperm rate (P < 0.05). In conclusion, excessive copper and absence of iron and manganese in serum as well as higher seminal plasma cadmium may reduce the utilization rate of semen by impairing sperm motility and morphology, indicating the importance of adding and monitoring microelements in boar diet.

Human Sperm Characteristics with Regard to Cobalt, Chromium, and Lead in Semen and Activity of Catalase in Seminal Plasma

We analyzed cobalt (Co), chromium (Cr), and lead (Pb) concentrations in human semen and catalase CAT activity in seminal plasma and the effects of their relations on the sperm quality. We obtained semen samples from men (n = 168) undergoing routine infertility evaluation. Studies included two groups based on the ejaculate parameters: I (n = 39; normal ejaculate; normozoospermia); II (n = 129; pathological spermiogram). We examined relationships and differences between Co, Cr, and Pb concentrations in seminal plasma, CAT activity, and semen parameters. We did not establish differences in Co, Cr, and Pb concentrations and CAT activity from men between normozoospermic and those with pathological spermiogram. We found a significantly lower Co concentration and CAT activity in males with normal sperm motility than in asthenozoospermic males. We found significantly lower Co and a higher Pb concentration in males with normal morphology of spermatozoa than in teratozoospermic males. We found a significantly higher Pb concentration in the individuals with consumption of alcohol than in those without consumption. There were significant correlations between Co and Pb concentrations, sperm progressive motility (A + B, i.e., fast and slow progressive motility; Co-negatively; Pb-positively), and normal morphology of spermatozoa (Co-negatively; Pb-positively). We found a significant negative correlation between Cr concentration and slow progressive motility, and between CAT activity and volume of ejaculate. Co, Cr, and Pb levels and CAT activity were related to sperm characteristics and male fertility. The impact of alcohol may be manifested by a disturbance in Pb equilibrium in the body. Co and Pb influence progressive motility and normal morphology of human spermatozoa. Thus, Co and Pb levels in semen may be a useful diagnostic in male infertility. Most of the results of this study are in contrast to expectations. Namely, Pb is a toxic element and its harmful effects (poor semen quality) may be expected already at relatively low level of Pb exposure and are particularly visible with increasing of Pb. Co and Cr(III) are essential elements and harmful effects may be expected at their deficiency and/or overexposure.

Trace elements content in semen and their interactions with sperm quality and RedOx status in freshwater fish Cyprinus carpio: A correlation study

Objective of the present study was to investigate interactions between trace elements content and RedOx status, as well as sperm quality parameters (motility features, DNA fragmentation) in fish spermatozoa in natural conditions. Reproductively mature male freshwater fish (n = 16) of Cyprinus carpio breed were used in the study. Trace elements content was determined in fish milt samples by inductively-coupled plasma optical emission spectrometry (ICP-OES) and by cold-vapor atomic absorption spectroscopy (CV-AAS). Sperm quality evaluation was realized by computer-assisted sperm analysis (CASA) quantifying several parameters: concentration, total motility, progressive motility, distance average path, distance curved line, distance straight line, velocity average path, velocity curved line, velocity straight line, straightness, linearity, amplitude of lateral head displacement and beat cross frequency. The general scheme of descending concentrations of trace metals in semen samples was following: Zn > Fe > Cu > As > Sr > Ni > Mn > Se > Pb > Cr > Cd > Hg. Total motility of spermatozoa was relatively high (91.45%), however progressive motility was not even half of this value (39.47%). Sperm DNA fragmentation values were relatively low (4.00-6.29%). The percentage of immotile spermatozoa showed a significant correlation with all RedOx status parameters and also with DNA fragmentation. Positive statistically significant correlations were observed between trace elements (Mn, Se, Sr, and Zn) and some qualitative spermatozoa parameters (velocity and distance parameters). Cu and Hg content shows similar negative associations with progressive motility. Hg also interacted with production of malondialdehyde. Overall, the present study suggests application of multi-component mixtures of environmentally related trace elements concentrations when assessing the potential reproductive risk.

Testicular toxicity and sperm quality following copper exposure in Wistar albino rats: ameliorative potentials of L-carnitine

Copper is a persistent toxic and bio-accumulative heavy metal of global concern. Continuous exposure of copper compounds of different origin is the most common form of copper poisoning and in turn adversely altering testis morphology and function and affecting sperm quality. L-carnitine has a vital role in the spermatogenesis, physiology of sperm, sperm production and quality. This study was designed to examine whether the detrimental effects of long-term copper consumption on sperm quality and testis function of Wistar albino rat could be prevented by L-carnitine therapy. The parameters included were sperm quality (concentration, viability, motility, and morphology), histopathology, serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), serum urea, serum creatinine, serum testosterone and testis antioxidant enzyme levels (superoxide dismutase and glutathione-S-transferase), and biomarkers of oxidative stress (lipid peroxidation and expression of heat shock protein 70 in testis). Three-month-old male Wistar rats (n = 30) were divided into six groups as group 1 (G1, 0.9% saline control), group 2 (G2, CuSO4 200 mg/kg dissolved in 0.9% saline water), groups 3 and 4 (G3 and G4, L-carnitine 50 and 100 mg/kg dissolved in 0.9% saline water, respectively), and groups 5 and 6 (G5 and G6, CuSO₄ 200 mg/kg plus L-carnitine, 50 and 100 mg/kg dissolved in 0.9% saline water, respectively). Doses of copper (200 mg/kg) and L-carnitine (50 and 100 mg/kg) alone and in combinations along with untreated control were administered orally for 30 days. The following morphological, physiological, and biochemical alterations were observed due to chronic exposure of copper (200 mg/kg) to rats in comparison with the untreated control: (1) generation of oxidative stress through rise in testis lipid peroxidation (12.21 vs 3.5 nmol MDA equivalents/mg protein) and upregulation of heat shock protein (overexpression of HSP70 in testis), (2) liver and kidney dysfunction [elevation in serum ALT (81.65 vs 48.08 IU/L), AST (156.82 vs 88.25 IU/L), ALP (230.54 vs 148.16 IU/L), urea (12.65 vs 7.45 mmol/L), and creatinine (80.61 vs 48.25 μmol/L) levels], (3) significant decrease in body (99.64 vs 106.09 g) and organ weights (liver-3.48 vs 4.99 g; kidney-429.29 vs 474.78 mg; testes-0.58 vs 0.96 g), (4) imbalance in hormonal and antioxidant enzyme concentrations [significant decline in serum testosterone (0.778 vs 3.226 ng/mL), superoxide dismutase (3.07 vs 8.55 μmol/mg protein), and glutathione-S-transferase (59.28 vs 115.58 nmol/mg protein) levels], (5) severe alterations in the testis histomorphology [sloughed cells (90.65%, score 4 vs 15.65%, score 1), vacuolization (85.95%, score 4 vs 11.45%, score 1), cellular debris along with degenerative characteristics, accentuated germ cell depletion in the seminiferous epithelium, severe damage of spermatogonia and Sertoli cells (73.56%, score 3 vs 0%, score 1)], (6) suppression of spermatogenic process [hypospermatogenesis (low Jhonsen testicular biopsy score 4 vs 9.5), decrease in tubules size (283.75 vs 321.25 μm in diameter), and no. of germ cells (81.8 vs 148.7/100 tubules), Leydig cells (5.2 vs 36.65/100 tubules), and Sertoli cells (8.1 vs 13.5/100 tubules)], (7) sperm transit time was shorter in caput and cauda and ensued in incomplete spermatogenic process and formation of immature sperm leading to infertility, (8) sperm quality was affected significantly [decreased daily sperm production (13.21 vs 26.9 × 10⁶ sperms/mL), sperm count (96.12 vs 154.25 × 10⁶/g), sperm viability (26.88 vs 91.65%), and sperm motility (38.48 vs 64.36%)], and (9) increase of head (32.82 vs 2.01%) and tail (14.85 vs 0.14%) morphologic abnormalities and DNA fragmentation index (88.37 vs 11.11%). Oxidative stress and their related events appear to be a potential mechanism involved in copper testicular toxicity and L-carnitine supplementation significantly modulated the possible adverse effects of copper on seminiferous tubules damage, testes function, spermatogenesis, and sperm quality. It was validated that the use of L-carnitine at doses of 50 and 100 mg/kg protects against copper-induced testicular tissue damage and acts as a therapeutic agent for copper heavy metal toxicity.

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.

Impact of elemental iron on human spermatozoa and mouse embryonic development in a defined synthetic culture medium

There is a paucity of studies on effect of iron in embryo culture procedures. This study aims to ascertain the optimal, tolerance and toxic levels of iron in a protein-free embryo culture medium (PFM) to determine the effect of iron on embryonic development. The application of PFM in assisted reproductive technologies (ART) is intended to eliminate disease transmission and improve ART treatment outcome. The optimal, tolerance and toxic levels of iron on human spermatozoa and mouse embryos were determined by challenging them with different levels of iron (ferric iron; Fe⁺³). Human normozoospermic semen samples (n=24) and days 1-4 Quakenbush Special (Qs) mouse embryos (n=1160) were incubated in PFM supplemented with different concentrations of Fe⁺³ over different periods of time. 2.0μg/mL (35.8μM) of Fe⁺³ was the optimal level of Fe⁺³ for human spermatozoa with a tolerance range of 0.5-2μg/mL; whereas a level of 0.11μg/mL (2μM) of Fe⁺³ was the optimum for day 2 embryos. Levels of ferric iron at 0.11 to 2.8μg/mL appear to enhance spermatozoa motility, preserve its DNA integrity and possibly increase percentage of blastocysts developed but levels of ferric iron >16μg/mL is hazardous for both spermatozoa and embryos. In spite of beneficial effects of iron it is premature to recommend its supplementation in embryo culture media because of the known deleterious nature of iron and the paucity of toxicological data. Toxicological studies must be performed following which it can be decided whether it is safe to consider iron as a supplement in human embryo and spermatozoa culture media.

Suppressive Effects of Copper Sulfate Accumulation on the Spermatogenesis of Rats

This study investigated the effect of copper sulfate (CuSO₄) in the rat spermatogenesis. Forty male rats, weighing 70-80 g, were randomly divided into four groups: control group (CG, 0 mg/kg BW), low-dose group (LG, 100 mg/kg BW), mid-dose group (MG, 200 mg/kg BW), and high-dose group (HG, 400 mg/kg BW). Rats were administered CuSO₄ by gavage for 30 days. A variety of measurements were taken including the testis coefficients, the sperm count, the abnormal malformation rate, testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) concentrations in the serum. In addition, glutathione peroxidase (GSH-P_x) and superoxide dismutase (SOD) activities, and malondialdehyde (MDA) concentration in the testis were determined. The results showed that in the CuSO₄-treated groups, the testis coefficients, sperm count, T, LH, and FSH concentrations, and GSH-P_x and SOD activities decreased, while the abnormal malformation rate and MDA concentration increased, compared with the CG. It indicates that CuSO₄ exposure impairs the sperm quality and inhibits secretion of sex hormone and gonadotropin, and testis anti-oxidative function, suppressing the rat spermatogenesis.

The effect of micronutrient supplements on male fertility

PURPOSE OF REVIEW

To describe the beneficial effects of micronutrient supplementation on male fertility.

RECENT FINDINGS

Several micronutrients have beneficial effects on sperm quality, as well on male fertility (e.g. pregnancy rate). A deliberate use of micronutrients might be helpful for infertile patients. Healthcare providers should be aware that supplements contain the studied dose.

SUMMARY

Male sterility is becoming increasingly important because of various factors. In addition to the avoidable risk factors (alcohol and smoking), unchangeable factors are also likely involved in the genesis. Modern reproductive medicine methods help resulting in decent pregnancy rates in subfertile men. However, in addition to reproductive medicine methods, factors other than cessation of smoking and alcohol consumption can influence the fertility of men. Several studies have reported a significant increase in sperm quality and pregnancy rates when the men were supplemented by specific vitamins and micronutrients.The present review gives an overview of the study results and discusses specific legal requirements (e.g. 'upper limits').

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.

Impact of oxidative stress on male fertility - a review

Oxidative stress is a state related to increased cellular damage caused by oxygen and oxygen-derived free radicals known as reactive oxygen species (ROS). It is a serious condition, as ROS and their metabolites attack DNA, lipids and proteins, alter enzymatic systems and cell signalling pathways, producing irreparable alterations, cell death and necrosis. While small amounts of ROS have been shown to be required for several functions of spermatozoa, their excessive levels can negatively impact the quality of spermatozoa and impair their overall fertilising capacity. These questions have recently attracted the attention of the scientific community; however, research aimed at exploring the role of oxidative stress and antioxidants associated with male fertility is still at its initial stages. This review summarises the current facts available in this field and intends to stimulate interest in basic and clinical research, especially in the development of effective methods for the diagnosis and therapy of semen damage caused by oxidative stress.

Zinc and iron concentration and SOD activity in human semen and seminal plasma

The aim of the present study was to measure zinc (Zn) and iron (Fe) concentration in human semen and superoxide dismutase (SOD) activity in seminal plasma and correlate the results with sperm quality. Semen samples were obtained from men (N = 168) undergoing routine infertility evaluation. The study design included two groups based on the ejaculate parameters. Group I (n = 39) consisted of males with normal ejaculate (normozoospermia), and group II (n = 129) consisted of males with pathological spermiogram. Seminal Zn and Fe were measured in 162 samples (group I, n = 38; group II, n = 124) and SOD activity in 149 samples (group I, n = 37; group II, n = 112). Correlations were found between SOD activity and Fe and Zn concentration, and between Fe and Zn concentration. SOD activity was negatively associated with volume of semen and positively associated with rapid progressive motility, nonprogressive motility, and concentration. Negative correlation was stated between Fe concentration and normal morphology. Mean SOD activity in seminal plasma of semen from men of group I was higher than in seminal plasma of semen from men of group II. Fe concentration was higher in teratozoospermic males than in males with normal morphology of spermatozoa in group II. Our results suggest that Fe may influence spermatozoa morphology.

In vitro copper toxicity on rabbit spermatozoa motility, morphology and cell membrane integrity

In this in vitro study the effects of copper sulphate on the motility, morphology and structural integrity of rabbit spermatozoa were investigated. The spermatozoa motility was evaluated by CASA method and Annexin analysis was used for detection of structural changes. For analysis of morphology samples of rabbit semen were fixed with Hancock's solution and stained with Giemsa, and for each sample at least 500 spermatozoa were evaluated. The concentration of copper in the medium varied from 3.57 to 4.85 microg CuSO4/mL. At Time 0 the highest motility was detected in the control group (57.78 +/- 3.90%). Motility in groups with copper administration was lower in comparison to control. Significant differences were detected in groups with 3.70-4.85 microg CuSO4/mL (P<0.05) at Time 0. After 1 h of incubation with copper sulphate the motility significantly decreased almost in all experimental groups. However, at Time 2 h significant increase of total motility was observed in groups with lower concentrations of copper (3.57 and 3.63 microg CuSO4/mL). After 24 and 48 h of incubation almost all the spermatozoa were dead recording no motility at all concentrations. The concentration- dependent decrease of spermatozoa motility up to 50% of control was detected for the group receiving highest copper administration (4.85 microg CuSO4/mL) at Times 1 and 2 h. Progressive motility had an identical trend to that of motility in all experimental groups, at all culture times and for all concentrations. Evaluation of distance and velocity parameters indicated that a sort of stress tolerance developed in lower concentrations (3.57 and 3.63 microg CuSO4/mL). At lower concentrations, an increase was noted for distance parameter DCL and velocity parameter VCL, indirectly confirming the significant motility and progressive motility increase. Other motility parameters (straightness index, linearity index, wobble and amplitude of lateral head displacement) revealed decrease in the group with the highest copper concentration (4.85 microg CuSO4/mL) in comparison to the control group after 2 h of incubation, only. No significant alteration was noted for these parameters in comparison to control at Times 0 and 1 h. The total percentage of morphologically abnormal spermatozoa was significantly higher (P<0.05) in the group with the highest copper concentration (46.20+/-5.54%) in comparison to control (30.60+/-2.91). Predominant morphological abnormalities were acrosomal changes, knob-twisted flagellum and small heads. Detection of spermatozoa with disordered membrane was carried out for groups with higher copper concentrations and control, using Annexin analysis. Analysis showed higher occurrence of positive spermatozoa in the copper-exposed groups. Some Annexin positive reactions from all spermatozoa were detected in the control group. In copper-exposed groups positive reaction proved alteration in anterior part of head (acrosome) and in connection segment (mid-piece) of spermatozoa. Detected data evidently confirm adverse effects of high copper sulphate concentrations in rabbit semen on parameters of spermatozoa motility, morphology and membrane integrity. This paper also indicates the lowest possible toxic concentration of copper (3.70 microg CuSO4/mL) to rabbit spermatozoa in relation to motility.

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

In this study the effect of cadmium on various parameters of spermatozoa motility, morphology as well as on the spermatozoa membrane integrity in rabbits was analyzed in vitro, experimental concentrations ranging from 0.62 to 0.98 micro g CdCl(2)/mL. Pooled rabbit (n = 5) semen was cultured in vitro with cadmium and subsequently diluted to various experimental concentrations apart from control which received no cadmium exposure. Using computer assisted semen analysis method (CASA) we detected decrease of total motility with in the higher concentration range at Time 0. However, with increasing time (after 1 and 2 h of culture), cadmium exerted deleterious effect leading to significant motility reduction in comparison to control. A similar trend was exhibited in case of progressive motility, too. Most of the spermatozoa distance and velocity parameters detected no significant change in comparison to control at the beginning of culture (Time 0), although the toxic effect became significant (P < 0.05) with the passage of culture time (Times 1 and 2 h) in all concentrations. Analysis of spermatozoa morphology detected significant (P < 0.05) alterations at higher concentrations. At higher concentrations acrosomal changes, head without flagellum/separated flagellum, broken flagellum and other abnormalities were significantly higher (P < 0.05), while knob-twisted flagellum and small heads differed significantly (P < 0.05) in comparison to control at all concentrations. In regards to flagellum torso, flagellum ball and retention of cytoplasmic drop statistically higher values (P < 0.05) were noted at the maxium experimental concentration only. Annexin analysis for detection of spermatozoa with disordered membranes revealed higher occurrence of positive spermatozoa in cadmium exposed groups. Annexin-positive reactions suggested alterations in anterior part of head (acrosome) and in flagellum (mitochondrial segment) of spermatozoa. This paper underlines that cadmium is highly toxic for rabbit spermatozoa, as visualized by the toxic effects on parameters of spermatozoa motility, morphology and membrane integrity. The toxic effect is more drastic at higher concentrations. This study also indicates that cadmium requires a minimum one hour incubation time to exert its deletorious effects on various parameters of spermatozoa, particularly at low concentrations.

In vitro effect of nickel on bovine spermatozoa motility and annexin V-labeled membrane changes

In this study the effect of in vitro culture of bovine spermatozoa with nickel (NiCl(2)) on spermatozoa motility and membrane changes was analyzed. The spermatozoa motility significantly decreased after 120 min of culture at the concentration of 1000 μM Ni ml(-1) (P < 0.05) and after 240 min of culture at the concentration of 500 and 1000 μM Ni ml(-1) (P < 0.001) as compared with control. The progressive motility was the highest in the control group and in the groups with the lowest nickel concentrations (7.8 and 125 μM Ni ml(-1)). The progressive spermatozoa motility was significantly altered even after 30 min of culture in the group with the highest nickel concentration (1000 μM Ni ml(-1)). A significant decrease in progressive motility from the concentration of 250 μM Ni ml(-1) was detected after 240 min of culture. Concentrations from 125 μM Ni ml(-1) in various time periods of culture stimulated spermatozoa motility after 30 min (P < 0.001), but later an inhibitory effect was noted. After 240 min of in vitro spermatozoa culture with 125 μM Ni ml(-1) a typical Annexin V fluorescence reaction was detected. Fluorescence was detected in mitochondrial segment of bovine spermatozoa. In spermatozoa exposed to higher nickel concentrations the Annexin V-positive reaction was detected also on the spermatozoa head membrane. In the group with the highest concentration and the longest time of exposure (1000 μM Ni ml(-1); 240 min) the apoptotic Annexin-positive regions were detected not only in the mitochondrial part, but also in the spermatozoa head (acrosomal and postacrosomal part), showing significant alteration of spermatozoa membrane integrity.

In vitro toxicity of mercuric chloride on rabbit spermatozoa motility and cell membrane integrity

In this in vitro study the effects of mercuric chloride on the motility and structural integrity of rabbit spermatozoa were investigated. The spermatozoa motility was evaluated using CASA method and Annexin analysis was used for detection of structural changes. The concentration of mercury in the medium varied from 5.0 to 83.3 microg HgCl(2)/mL. At Time 0 the highest motility was detected in the control group (67.09 +/- 8.72%). Motility in groups with mercury administration was lower in comparison with control. Significant differences were detected in groups with 50.0-83.3 microg HgCl(2)/mL (P < 0.001) at Time 0. After 60 and 120 minutes of incubation with mercuric chloride the motility significantly decreased almost in all experimental groups. Progressive motility had a decreasing trend in all experimental groups. At time 60 and 120 significant differences were noted in the group receiving 6.25-83.3 microg HgCl(2)/mL. Significant differences were detected in all experimental groups, except the group with the lowest mercuric chloride administration. The concentration-dependent decrease of spermatozoa progressive motility up to 50% of control was detected for groups receiving 50.0 - 83.3 microg HgCl(2)/mL at Time 0, for groups receiving 12.5-83.3 microg HgCl(2)/mL at Time 60 and 120, decreasing from 36.46 +/- 18.73% to 1.03 +/- 2.50%. Detailed evaluation of spermatozoa distance (DAP, DCL, and DSL) and velocity (VAP, VCL, and VSL) parameters as well as straightness (STR), linearity (LIN), wobble (WOB), amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) of spermatozoa revealed decrease in groups with the highest mercury concentration in comparison with the control group at all time periods. Detection of spermatozoa with disordered membrane was carried out for groups with higher mercury concentrations and control, using Annexin analysis. Analysis showed higher occurrence of positive spermatozoa in the mercury exposed groups. Some Annexin positive reactions from all spermatozoa were detected in the control group. In mercury-exposed groups positive reaction proved alteration in anterial part of head (acrosome), connection part (connection piece) and in mitochondrial segment. Detected data evidently confirm adverse effects of high mercuric chloride concentrations in rabbit semen on spermatozoa motility parameters.

In vitro study on the effects of lead and mercury on porcine ovarian granulosa cells

The heavy metals lead (Pb) and mercury (Hg) pose potential risks to sustainability of environment and thus to our future generations. General objective of this in vitro study was to examine the secretory activity of porcine ovarian granulosa cells after Pb and Hg administration and to outline the potential intracellular mediators of its effects. For this purpose, release of insulin-like growth factor I (IGF-I) and steroid hormone progesterone (P(4)), expression of proliferation- related (cyclin B1) and apoptosis-related (caspase-3) peptides was examined in porcine ovarian granulosa cells after heavy metals administration. Obtained data indicate Pb-induced inhibition of IGF-I release at lower doses (0.063 mg/mL and 0.046 mg/mL) by ovarian granulosa cells. However, P(4) release was not influenced by Pb addition, while the expression of cyclin B1 and caspase-3 was induced by Pb addition. These results indicate that Pb can affect the pathway of proliferation and apoptosis of porcine ovarian granulosa cells through intracellular substances such as cyclin B1 and caspase-3. On the other hand, the P(4) release by ovarian granulosa cells of pregnant gilts was stimulated by experimental Pb administration at doses of 0.25 mg/mL and 0.063 mg/mL and experimental Hg administration at doses 0.25 mg/mL and 0.083 mg/mL. P(4) release by ovarian cells of pregnant gilts was not influenced by a combinatory dose of FSH (1.0 ng/mL) + Pb (0.083 mg/mL) + Hg (0.083 mg/mL) but it was inhibited by experimental administration of FSH (10 ng/mL) + Pb (0.25 ng/mL) + Hg (0.25 ng/mL). Possible involvement of heavy metals - Pb and Hg and pituitary hormone FSH, in the regulation of P(4) release by porcine ovarian granulosa cells of pregnant gilts was noted. Data obtained from in vitro studies suggest the dose dependent association of heavy metals administration with the hormonal release by porcine ovarian granulosa cells. This association also depended on pregnancy of the gilts.

3-Ethyl-4-(p-chlorobenzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one (EPHBAT) as precipitant for carrier element free coprecipitation and speciation of chromium(III) and chromium(VI)

A method for the separation and speciative determination of Cr(VI) and Cr(III) has been developed. The procedure is based on coprecipitation of Cr(III) on 3-ethyl-4-(p-chlorobenzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one (EPHBAT) without carrier element. The Cr(III) can be selectively precipitated on EPHBAT in the pH range of 8.0-9.0, while Cr(VI) cannot be retained. Total chromium was determined after the reduction of Cr(VI) to Cr(III) with 0.5 mL of concentrated H2SO4 and 0.5 mL of ethanol. Cr(VI) concentrations were obtained as the respective differences between total chromium and Cr(III). Experiments were performed to optimize conditions, such as pH, amounts of EPHBAT, sample volume, etc. A preconcentration factor of 50-fold was achieved for Cr(III). The detection limit of the method for Cr(III) was 1.0 microg L(-1). To validate the developed method, the certified reference materials (NIST SRM 1573a and GBW 0703) were analyzed. The method was applied for the speciation of chromium in spiked natural water samples with satisfactory results.