Metallothionein, essential elements and lipid peroxidation in mercury-exposed suckling rats pretreated with selenium.

Detoxification of mercury (Hg) with selenium (Se) in the early postnatal period with regard to the expression of metallothionein protein (MT), essential element status, and lipid peroxidation level in tissues has not been studied. Seven-day-old Wistar pups were orally pretreated with Se [6 µmol Na2SeO3/kg body weight (b.w.)] for 3 days and then cotreated with Hg (6 µmol HgCl2/kg b.w.) for the following 4 days. This group (Se + Hg) was compared to the groups treated with Hg, Se, or vehicle (control). Compared to the Hg-group, Se + Hg-group exhibited lower renal MT expression, reduced accumulation of Hg, Cu and Zn, and reduced excretion of Se, Hg and Zn in urine. In the liver, MT was stimulated by Se treatment in both, Se and Se + Hg-group. Hepatic and brain levels of the endogenous essential elements Cu, Fe, Mg, and Zn remained unchanged in all of the studied groups. Brain Hg levels and oxidation of lipids measured as thiobarbituric acid reactive substances were diminished in Se + Hg-group of pups compared to the Hg-group. This study suggests that Se pretreatment can help reduce Hg in the tissues of suckling rats, simultaneously preventing impairment of essential element levels in the kidneys and their excessive excretion via urine. Also, Se was shown to prevent oxidative damage of lipids in the brain, which is particularly susceptible to Hg during the early postnatal period.

Mercury disposition in suckling rats: comparative assessment following parenteral exposure to thiomersal and mercuric chloride.

Due to the facts that thiomersal-containing vaccine is still in use in many developing countries, and all forms of mercury have recognised neurotoxic, nephrotoxic, and other toxic effects, studies on disposition of ethylmercury and other mercury forms are still justified, especially at young age. Our investigation aimed at comparing mercury distribution and rate of excretion in the early period of life following exposure to either thiomersal (TM) or mercuric chloride (HgCl2) in suckling rats. Three experimental groups were studied: control, TM, and HgCl2, with 12 to18 pups in each. Both forms of mercury were administered subcutaneously in equimolar quantities (0.81 µmol/kg b.w.) three times during the suckling period (on the days of birth 7, 9, and 11) to mimic the vaccination regimen in infants. After the last administration of TM or HgCl2, total mercury retention and excretion was assessed during following six days. In TM-exposed group mercury retention was higher in the brain, enteral excretion was similar, and urinary excretion was much lower compared to HgCl2-exposed sucklings. More research is still needed to elucidate all aspects of toxicokinetics and most harmful neurotoxic potential of various forms of mercury, especially in the earliest period of life.

Salivary concentrations of nickel and chromium in patients with burning mouth syndrome.

It has been documented in vitro and in vivo that metal dental appliances release metal ions due to corrosion. Dentists must choose among many dental casting alloys available, often without knowledge of their biological properties and effect on oral mucosa. The aim of this study was to measure metal content of nickel (Ni) and chromium (Cr) in whole saliva of 85 patients with and without metal dental appliances. Unstimulated whole saliva was collected and analyzed by using electrothermal atomic absorption spectrometry. History data, subjective complaints and objective findings on oral mucosa were recorded. The concentration of metal ions was investigated in correlation to burning mouth syndrome, erythema of oral mucosa, pH and smoking habit. Results showed a higher Ni concentration in patients with metal restorations, especially wearers of predominantly base metal appliances. The concentration of Cr showed no difference between patient groups. Although burning mouth syndrome was more frequent in the group with dental casting alloys, there was no correlation between higher Ni and Cr concentrations and burning mouth syndrome. Erythema of oral mucosa was a common finding in study patients, but did not correlate with salivary Ni and Cr ion concentrations. Salivary Ni and Cr concentrations were not related to either pH or smoking habit.

Effect of selenium pre-treatment on antioxidative enzymes and lipid peroxidation in Cd-exposed suckling rats.

Since there are no data about the protective role of selenium (Se) against cadmium (Cd)-induced oxidative damage in early life, we studied the effect of Se supplementation on antioxidative enzyme activity and lipid peroxidation (through thiobarbituric acid reactive substances; TBARS) in suckling Wistar rats exposed to Cd. Treated animals received either Se alone for 9 days (8 µmol, i.e., 0.6 mg Se as Na(2)SeO(3) kg(-1) b.w., daily, orally; Se group), Cd alone for 5 days (8 µmol, i.e., 0.9 mg Cd as CdCl(2) kg(-1) b.w., daily, orally; Cd group), or pre-treatment with Se for 4 days and then co-treatment with Cd for the following 5 days (Se + Cd group). Our results showed that selenium supplementation, with and without Cd, increased SOD activity in the brain and kidney, but not in the liver and GSH-Px activity across all tissues compared to control rats receiving distilled water. Relative to the Cd group, Se + Cd group had higher kidney and brain SOD and GSH-Px activity (but not the liver), while in the liver caused increased and in the brain decreased TBARS level. These results suggest that Se stimulates antioxidative enzymes in immature kidney and brain of Cd-exposed rats and could protect against oxidative damage.

The effect of dietary selenium supplementation on cadmium absorption and retention in suckling rats.

Selenium (Se) reduces cadmium (Cd) toxicity in adult animals, but its effects in newborn animals are still unknown. This study investigated Cd (as CdCl2) absorption, distribution, and retention in suckling rats receiving oral Se supplementation (as Na2SeO3) in equimolar doses (8 µmol Cd and/or Se per kg b.w./day). Selenium was given either before and during Cd exposure (Sepre + Cd group; pretreatment group) or only during Cd exposure (Se + Cd group). Rats were treated from postnatal day (PND) 6-14 as follows: controls (H2O, PND 6-14), Se (PND 10-14), Cd (PND 10-14), Sepre + Cd (Se PND 6-14 + Cd PND 10-14) and Se + Cd (Se + Cd PND 10-14). Selenium supplementation, especially pre-treatment, decreased Cd levels in the blood, brain, liver and kidney of suckling rats. Selenium levels in plasma, brain, and kidney also decreased. These findings suggest that higher Se intake could efficiently reduce Cd retention during the suckling period.

Influence of selenium dose on mercury distribution and retention in suckling rats.

It is well known that metal-metal interactions in the body are age-dependent. We studied the influence of increasing selenium (Se) doses on mercury (Hg) distribution and retention in the postnatal period in Hg-exposed suckling rats. Seven-day-old Wistar pups were pretreated with three different oral doses of Se as sodium selenite (6.45, 12.9 and 19.4 micromol Se kg(-1) b.w.) over 3 days. This was followed by simultaneous Se (as sodium selenite) and Hg (as mercury chloride) oral administration over 4 days. The molar ratio between Se and Hg given to pups was 1:1, 2:1 and 3:1, respectively. Mercury and Se were measured in brain, kidneys, liver, plasma, erythrocytes and urine of pups on the day after the last administration by atomic absorption spectrometry. Results showed that in all samples Se concentrations rose almost proportionally to the dose of Se given to pups. Mercury concentration in organs, plasma and urine decreased with higher oral doses of Se. However, Hg concentration in erythrocytes increased with increasing Se dose. There was evidently a redistribution of Hg from plasma to erythrocytes at higher ratio of Se:Hg. Approximately equimolar doses of Se and Hg are necessary to produce maximum uptake of Hg by plasma and liver and minimum retention of Hg in the kidney and erythrocytes.

Comparison of calcium, magnesium, sodium, potassium, zinc, and creatinine concentration in 24-h and spot urine samples in women.

BACKGROUND: The 24-h urine sample is considered as the most reliable material for testing many but not necessarily all constituents in urine. However, its collection is tedious for both patients and research participants. The aim of this study was to compare concentrations of essential elements calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and zinc (Zn) in 24-h and spot urine samples. METHODS: Urine samples were collected from 143 generally healthy women, aged 30-79 years. Fasting spot urine was collected immediately after the end of the 24-h collection, therefore being of the same content as the first morning urine which ended the 24-h collection. Elements were analyzed by flame atomic absorption/emission spectrometry and expressed as mg/g and/or mmol/mol of creatinine (Cr). Spearman rank order correlations between 24-h and spot urine were carried out for each element. Ratios of elements in 24-h to spot urine samples were calculated to estimate the element-proportion of spot in the 24-h sample. RESULTS: All coefficients of correlation between 24-h and spot urine of measured elements and Cr were significant (p<0.05): Zn (0.637), Mg (0.623), Ca (0.603), Na (0.452), K (0.396), and Cr (0.217). Ratios of 24-h to spot urine samples for each element (except K) were similar and close to 2, indicating uniform proportion of elements from spot urine sample in the 24-h sample. In addition, a high correlation between various pairs of elements was obtained in both 24-h and spot urine; the highest being between Na/Ca (0.435) and (0.578), respectively. This is in accordance with theoretical presumptions and previous findings regarding those relationships. CONCLUSIONS: Although replacing burdensome 24-h urine collection with spot urine sampling might not provide the solution in all cases, our results show that for the elements analyzed, spot urine could be a reliable alternative.

Nutrition and lifestyle in relation to bone health and body weight in Croatian postmenopausal women.

The objective was to investigate the association of nutrients and lifestyle modifiers with bone mineral density (BMD) and weight and/or body mass index (BMI) in 120 healthy Croatian postmenopausal women. The hip and spine BMD was assessed by Lunar Prodigy (GE Medical Systems). Nutrient assessment from 3-day records was analyzed using the US Department of Agriculture Food Composition Tables and the Croatian National Institute of Public Health database. Subjects were asked to record the consumption of alcohol, coffee, tea and mineral waters, the amount of salt added to foods and smoking habits, as well as involvement in recreational activities, walking and heavy housework. Spot urine samples were analyzed for calcium, magnesium, sodium, potassium and zinc and were normalized by creatinine. Alcohol showed statistically significant positive association with femur and spine BMD and its consumption was higher in subjects without osteoporosis. Urinary sodium/creatinine was significantly positively associated with femoral neck and trochanter BMD, while urinary calcium/creatinine was significantly negatively associated with trochanter, total femur and spine BMD. Consumption of mineral waters was inversely associated with weight/BMI and so were dietary fiber and magnesium. In conclusion, moderate alcohol consumption and urinary sodium were positively associated while urinary calcium was negatively associated with either hip and/or spine BMD. Mineral waters, higher fiber and magnesium intake were beneficial for weight/BMI in this population of apparently healthy Croatian women.

Peak bone density in Croatian women: variations at different skeletal sites.

It is known that different skeletal sites have different peak bone mass at different times and lose bone at different rates. The purpose of the study was to assess bone mineral density (BMD) in healthy female student population (N=220), aged 18-25 yr and to analyze whether young women of that age have already started to lose the bone mass at the trabecular and cortical parts of skeleton. The influence of dietary intake and physical activity on their bone mass was also assessed. BMD was measured, using dual-energy X-ray absorptiometry technique, in spine, proximal femur, and distal third of the radius and in total body. Significant negative correlation between age and bone mass was found in all skeletal regions (p<0.05 spine; p<0.0001 total femur; and p<0.01 total body) except in cortical part of the radius. Peak bone mass in young Croatian women was achieved before the age of 20, but later in the long-bone cortical skeleton, where BMD continued to increase after mid-20s. The BMD values are comparable with those from National Health and Nutrition Examination Survey study, except for the cortical part of the radius, where it is significantly lower. Body weight and physical activity were the most significant positive predictors of bone density in all measured sites.

Biological availability of selenosugars in rats.

The biological availability and metabolism of two selenosugars orally administered to rats were investigated. Two other selenium species, selenite and trimethylselenonium ion (TMSe) were included in the study as positive and negative controls, respectively. Male Wistar strain rats (three per group) at 8 weeks of age were exposed to sodium selenite, TMSe, selenosugar 1 (methyl-2-acetamido-2-deoxy-1-seleno-beta-D-galactopyranoside) or selenosugar 2 (methyl-2-acetamido-2-deoxy-1-seleno-beta-D-glucopyranoside) through drinking water for 48 h. Total selenium concentrations (ICPMS) and selenium species concentrations (HPLC/ICPMS) were determined in urine samples collected in two 24h periods during the exposure, and total selenium concentrations in liver, kidney, small intestine and blood were determined at the end of the experiment. The major species found in background urine were selenosugar 1 (major metabolite) and TMSe (minor metabolite). Rats exposed to selenite excreted large quantities of selenosugars and TMSe consistent with efficient uptake and biotransformation of selenite, whereas TMSe-exposed rats excreted large quantities of TMSe, but there was no significant increase of other selenium metabolites, consistent with TMSe being taken up and excreted unchanged. Rats exposed to selenosugars, however, excreted significant quantities of TMSe suggesting that the sugars were at least partly biologically available and biotransformed. Rats exposed to selenite accumulated selenium in the liver, kidney, small intestine and blood, whereas no accumulation was observed for the other samples except for small increases in selenium concentrations of small intestine from the two selenosugar-exposed groups.

Heavy metal concentrations in ground beetles, leaf litter, and soil of a forest ecosystem.

The objective of this study was to quantify the relationships between heavy metal concentrations in soil, leaf litter, and ground beetles at four sampling sites of a forest ecosystem in Medvednica Nature Park, Croatia. Ground beetles were sampled by pitfall trapping. Specimens were dry-ashed and soil and beetle samples digested with nitric acid. Lead, cadmium, copper, zinc, manganese, and iron were analyzed using atomic absorption spectrometry. Statistically significant differences between plots were found for lead, cadmium, and iron in ground beetles. Correlations between ground beetles and soil or leaf litter were positive for lead and cadmium concentrations and negative for iron concentration. Differences in species metal concentrations were recorded. Higher concentrations of all studied metals were found in female beetles. However, a significant difference between sexes was found only for manganese. Significant differences in species metal concentrations were found for species that differ in feeding strategies and age based on breeding season and emergence of young adults.

Comparison of organic and inorganic mercury distribution in suckling rat.

Thiomersal is used as a preservative in vaccines given to small children. The metabolic product of thiomersal is ethylmercury and its distribution and kinetics are still not known, especially at this early age. The purpose of this study was to compare the body distribution of two forms of mercury: organic (thiomersal) and inorganic (mercury(2+) chloride) in very young, suckling rats. Mercury was applied subcutaneously three times during the suckling period on days 7, 9 and 11 of pups age, imitating the vaccination of infants. A single dose of mercury was equimolar in both exposed groups, i.e. 0.81 micromol Hg kg(-1). At 14 days of age the animals were killed and the total mercury analysed in blood and organs (kidney, liver and brain). The analytical method applied was total decomposition, amalgamation, atomic absorption spectrometry. The results showed that the level of mercury was higher in the liver and kidney of the inorganic mercury group than in the thiomersal exposed group. However, the brain and blood concentrations of mercury were higher in the thiomersal exposed group. These results need to be clarified by additional data on the kinetic pathways of ethylmercury compared with inorganic mercury.

Chelators as antidotes of metal toxicity: therapeutic and experimental aspects.

The effects of chelating drugs used clinically as antidotes to metal toxicity are reviewed. Human exposure to a number of metals such as lead, cadmium, mercury, manganese, aluminum, iron, copper, thallium, arsenic, chromium, nickel and platinum may lead to toxic effects, which are different for each metal. Similarly the pharmacokinetic data, clinical use and adverse effects of most of the chelating drugs used in human metal poisoning are also different for each chelating drug. The chelating drugs with worldwide application are dimercaprol (BAL), succimer (meso-DMSA), unithiol (DMPS), D-penicillamine (DPA), N-acetyl-D-penicillamine (NAPA), calcium disodium ethylenediaminetetraacetate (CaNa(2)EDTA), calcium trisodium or zinc trisodium diethylenetriaminepentaacetate (CaNa(3)DTPA, ZnNa(3)DTPA), deferoxamine (DFO), deferiprone (L1), triethylenetetraamine (trientine), N-acetylcysteine (NAC), and Prussian blue (PB). Several new synthetic homologues and experimental chelating agents have been designed and tested in vivo for their metal binding effects. These include three groups of synthetic chelators, namely the polyaminopolycarboxylic acids (EDTA and DTPA), the derivatives of BAL (DMPS, DMSA and mono- and dialkylesters of DMSA) and the carbodithioates. Many factors have been shown to affect the efficacy of the chelation treatment in metal poisoning. Within this context it has been shown in experiments using young and adult animals that metal toxicity and chelation effects could be influenced by age. These findings may have a bearing in the design of new therapeutic chelation protocols for metal toxicity.

Mercury chloride genotoxicity in rats following oral exposure, evaluated by comet assay and micronucleus test.

Mercury is a toxic element which is easily absorbed after ingestion or inhalation and deposited mainly in the kidney. The aim of this study was to evaluate the effects of mercury chloride in rats. Female rats, aged 14 weeks, were receiving mercury chloride in oral doses of 0.068, 0.136, and 0.272 mg kg(-1) body weight (b.wt.) for five consecutive days. Three days after the last dose, the animals were killed. The liver and the kidney were dissected and mercury measured using vapour generation atomic absorption spectrometry. The results show a significant increase in mercury mass fraction in the kidney after two higher doses of mercury chloride, while liver mercury burden showed a significant increase only after the highest dose. Blood samples were analysed using the comet assay and supravitally acridine orange stained micronucleus test. Tail length, tail moment and micronucleus frequency were significantly higher in the treated rats than in control rats, regardless of the dose of mercury chloride, while the difference between the treated groups for both comet and micronucleus parameters was not statistically significant.

Sodium and calcium intakes and bone mass in rats revisited.

OBJECTIVE: High sodium intake accompanied by insufficient dietary calcium may have detrimental effects on bone mass. Our study evaluated the effects of increased sodium and decreased calcium intakes on bone mineral density (BMD) and bone mineral content (BMC) in rats. METHODS: Four-month-old female Wistar rats were given deionized water or 1.8% solution of sodium chloride in deionized water and fed normal (1.2%) or marginal (0.33%) calcium in the diet for 2 mo. At the end of the experiment, BMD and BMC of the whole body and urinary sodium and calcium excretion were evaluated. All rats were killed and right femurs were removed to assess dry and ash weights. Two-way analysis of variance was used to evaluate effect of salt intake and effect of dietary calcium on these parameters. RESULTS: Salt-loaded animals had greater water consumption during the entire 2-mo period and significantly lower body weight from week 5 of the experiment. High salt intake increased urine volume and urinary excretion of sodium and calcium. Urinary calcium was about five times higher in salt-loaded animals than in rats on deionized water irrespective of dietary calcium content. Calcium in diet itself had no significant effect on these parameters. High salt intake slightly, but not significantly, decreased BMD, BMC, and femur weights. Lower calcium in diet significantly decreased BMD, and its effect on femur ash weight almost reached a level of significance. CONCLUSION: We confirmed the benefit of adequate calcium intake to BMD. Under our experimental condition, high salt intake in rats for 2 mo had no statistically significant effect on femur weights, BMD, or BMC even with marginal calcium in the diet.

Regulation of manganese accumulation in perinatally exposed rat pups.

The risk of manganese (Mn)-related ill effects in the neonate has been the topic of several investigations because in formula-fed infants Mn intake is much higher than in breast-fed infants. In the young, when Mn homeostasis is not yet developed, increased Mn intake might pose a neurotoxic risk. Our work aimed at collecting new data on Mn accumulation during the perinatal period by using an experimental rat model in pups whose mothers were exposed orally to Mn in drink (as manganese chloride; dose of 2000 ppm Mn) throughout pregnancy and 11 days of lactation. Pups were cross-fostered at birth and placental and mammary transfer of Mn at birth and at the age of 11 days was evaluated. The total pup body burden of Mn was analysed by atomic absorption spectrometry. Concentrations of iron (Fe), zinc (Zn) and calcium (Ca) also were analysed at the end of the experiment. The concentration of Mn in perinatally exposed pups was 6-8 times higher than in controls, irrespective of the period and duration of exposure. After cessation of exposure, the Mn concentration decreased almost to control levels. Concentrations of other essential elements (Fe, Zn, Ca) were not affected by Mn exposure. Our results indicate the existence of an accurate regulation of Mn accumulation in pups exposed to Mn during the perinatal period.

Simultaneous administration of sodium selenite and mercuric chloride decreases efficacy of DMSA and DMPS in mercury elimination in rats.

Two chelating agents meso-2,3-dimercaptosuccinic acid (DMSA) and sodium 2,3-dimercapto-propane-1-sulphonate (DMPS) were tested for their efficiency in mercury removal from the body of rats in the presence and in the absence of selenium. Female Wistar rats were given a single intraperitoneal injection of mercuric chloride or an equimolar mixture of mercuric chloride and sodium selenite (1.5 micromol/kg body weight). The chelating agents were given orally, in excess (500 micromol DMSA/kg body weight; 300 micromol DMPS/kg body weight), 30 min after the administration of mercury and selenium. The animals were euthanized 24 h after the treatment and mercury in the kidney, liver, and 24 h urine was determined using cold vapour atomic absorption spectrometry (CV-AAS). The simultaneous administration of mercuric chloride and sodium selenite led to a redistribution of mercury in the organs, so that accumulation of mercury in the kidneys was decreased and in the liver increased. Selenite also caused decrease in the level of urinary mercury excretion. Both chelating agents were effective in mercury removal from the body, by increasing its urinary excretion. However, when animals were simultaneously treated with mercury and selenite, the rise of mercury excreted in the urine due to the treatment with chelating agents was lower when compared to animals receiving mercury without selenite. It is concluded that sodium selenite decreases the efficiency of DMSA and DMPS in mercury removal from the body of rats.

Combined early treatment with chelating agents DMSA and CaDTPA in acute oral cadmium exposure.

The influence of chelating agents: meso-2,3-dimercaptosuccinic acid (DMSA); calcium trisodium diethylenetriaminepentaacetate (CaDTPA) and their combination on mobilisation of cadmium (Cd) was compared in female albino rats. After oral Cd administration chelators were applied either orally (DMSA) or intraperitoneally (CaDTPA) at various short time intervals after Cd. Three experiments were carried out with four treatment groups in each: 1) Cd (control); 2) Cd+DMSA; 3) Cd+CaDTPA; 4) Cd+DMSA+CaDTPA. Time intervals for chelator treatment after Cd administration were: immediate application in the first, half an hour in the second and one hour in the third experiment. At the end of each experiment cadmium was analysed in kidney and liver. Additionally in experiment 3 essential elements (Fe, Cu, Zn) were also determined in the same organs. In experiment 2 the effect of the treatment on urinary elimination of cadmium, copper and zinc were analysed. Results showed that the efficiency of Cd removal from the body (kidneys and liver) is lower when the time between Cd and chelating agents administration is longer. The two chelators differ in efficiency in mobilizing Cd, with DMSA being more efficient than CaDTPA. The combined therapy with the two chelators gave generally better results. It seems that DMSA which is given orally after oral Cd administration removes this element very efficiently from the gastrointestinal tract. CaDTPA, however, which is given parenterally removes absorbed Cd less efficiently, Organs are not significantly depleted in iron and copper after chelation treatment. Only zinc concentration was, however, significantly lower in the liver and higher in kidneys only after CaDTPA and combined DMSA+CaDTPA chelation.

Succimer treatment and calcium supplementation reduce tissue lead in suckling rats.

The effect of combined treatment with meso-2,3-dimercaptosuccinic acid (DMSA) and calcium supplementation in reducing lead absorption and enhancing lead elimination was evaluated in suckling rats under two experimental conditions: during ongoing oral lead exposure (lead acetate, 2 mg Pb kg(-1) day(-1), total dose 16 mg Pb kg(-1)) or after lead exposure (72 h after a 2-day lead exposure, total dose 12 mg Pb kg(-1) s.c.). The artificial feeding method was used for calcium supplementation, with 6% Ca (as CaHPO(4)) suspension in cow's milk to increase the daily calcium intake about three times above control values. Artificial feeding lasted for 7 h a day over eight consecutive days. During this period DMSA was administered on 6 days twice a day (0.5 mmol kg(-1) day(-1) p.o.). At the end of the experiments, Pb, Ca and Zn in the carcass and Pb, Fe and Cu in the liver, kidneys and brain were analysed by atomic absorption spectrometry. Calcium supplementation during lead exposure reduced tissue lead but had no effect when applied after lead exposure, and DMSA administered either during or after lead exposure lowered the tissue lead. Combined treatment during ongoing lead exposure caused a greater reduction in tissue lead than either DMSA or calcium treatment alone. When administered after lead exposure, it had no advantage over DMSA treatment alone but did not impair its efficacy. Combined treatment had no influence on growth and did not seriously disturb essential element status. It is concluded that calcium supplementation could be applied during DMSA therapy, when indicated.

Low iron diet and parenteral cadmium exposure in pregnant rats: the effects on trace elements and fetal viability.

The effects of latent iron deficiency combined with parenteral subchronic or acute cadmium exposure during pregnancy on maternal and fetal tissue distribution of cadmium, iron and zinc, and on fetal viability were evaluated. Timed-pregnant Sprague-Dawley rats were fed on semisynthetic test diets with either high iron (240 mg kg) or low iron (10 mg kg), and concomitantly exposed to 0, 3 or 5 mg cadmium (as anhydrous CdCl2) per kilogram body weight. Animals were exposed to cadmium from gestation day 1 through 19 by subcutaneously implanted mini pumps (Subchronic exposure) or on gestation day 15 by a single subcutaneous injection (Acute exposure). All rats were killed on gestation day 19. Blood samples, selected organs and fetuses were removed and prepared for element analyses by atomic absorption spectrometry. Low iron diet caused decreases in maternal body weight, maternal and fetal liver weights, placental weights and tissue iron concentrations. By cadmium exposure, both subchronic and acute, tissue cadmium concentrations were increased and the increase was dose-related, maternal liver and kidney zinc concentrations were increased, and fetal zinc concentration was decreased. Cadmium concentration in maternal liver was additionally increased by low iron diet. Acute cadmium exposure caused lower maternal body and organ weights, high fetal mortality, and decreased fetal weights of survivors. In conclusion, parenteral cadmium exposure during pregnancy causes perturbations in essential elements in maternal and fetal compartments. Acute cadmium exposure in the last trimester of gestation poses a risk for fetal viability especially when combined with low iron in maternal diet.