Metal Concentrations In Liver Research Articles

Metal exposure assessment in native fish, Mullus barbatus L., from the Eastern Adriatic Sea

Metallothionein (MT) and metal (Zn, Cu, Fe, Mn, Cd) association in the cytosol of liver, kidney and intestine was studied on native Mullus barbatus specimens. Investigated parameters of all specimens (1 to 8-year-old) were related to the fish length, which reflects fish growth and aging. Cytosolic metal concentrations in liver, kidney and intestine are tissue specific but in general decrease as follows: Fe ≈ Zn > Cu > Mn > Cd. Metallothionein levels are also tissue specific with the highest level in intestine, followed by kidney and liver. Percentage partition of MT and Zn in liver, kidney and intestine cytosol of red mullet is comparable. Associations of MT and metals that induce MT synthesis exist in liver for MT/Zn ( r = 0.28) and MT/Cu ( r = 0.26) and in intestine for MT/Cu ( r = 0.38). Unlike essential metals, there is no significant correlation between MT and the toxic metal Cd, what is ascribed to its very low cytosolic concentration. The most pronounced size-related accumulation is found for the toxic metal Cd in liver cytosol ( r = 0.69), indicating chronic Cd accumulation. Negative correlation between metals (Cd, Zn, Fe, Mn) and the condition factor also indicates chronic metal effects and their metabolic impact.

Determination of metals in fish and mussel species by inductively coupled plasma-atomic emission spectrometry

The concentrations of cadmium, iron, lead, zinc, copper, manganese, nickel, chromium and cobalt were determined by ICP-AES in muscles, livers, gills and skins of two fish ( Clarias gariepinus and Carasobarbus luteus), and in muscles and gills of two mussel species ( Unio terminalis and Potamida littoralis) sampled from the Lake Gölbaşı. Iron showed the highest levels in all examined tissues of both fish species. Following Fe; Zn showed the second highest levels in all examined tissues of both fish species except Mn levels in muscle and gill of C. luteus. In both mussel species, to the contrary fish, manganese showed the highest levels in examined tissues, and followed by Fe. In both fish species, the all metal concentrations in livers were higher than those in muscles. Concentrations in tissues of the analyzed metals were significantly affected by species. There were differences between the metal levels in the similar tissues of the different species ( p < 0.05). At the same time, there was also the differences between the metal concentrations in different tissues of the same species ( p < 0.05). Metal levels in tissues were compared with national and international permissible limits. Metal concentrations in both edible and other tissues of the sampled species were within the permissible safety levels for human uses.

Bioaccumulation of heavy metals in Liza saliens from the Esmoriz–Paramos coastal lagoon, Portugal

Heavy metal (Cu and Zn) concentrations in liver, gills, and muscle of leaping grey mullet, Liza saliens, from the Portuguese Esmoriz–Paramos coastal lagoon were measured to evaluate their bioaccumulation as a function of sediment contamination. The highest metal concentrations were observed in the liver (254 mg Cu kg −1) and gills (114 mg Zn kg −1). Bioaccumulation factors (BAFs) were found to follow the order: Cu-liver>Cu-gills>Cu-muscle and Zn-gills>Zn-liver>Zn-muscle. The highest BAFs were observed in the organs mainly implicated in metal metabolism and a significant positive relationship was found between BAFs and fish age. These results suggest the loss of homeostatic capacity of L. saliens under chronic metal exposure leading to bioaccumulation. Furthermore, Cu-liver and Zn-gills accumulation can be good environmental indicators of metal stress in L. saliens.

Heavy metal contaminants and processing effects on the composition, storage stability and fatty acid profiles of five common commercially available fish species in Oron Local Government, Nigeria

Five commercially available common fish species: catfish ( Chsysichthyes nigrodigitatus), tilapia ( Oreochromis nilotichus), ilisha (Ilisha africana), bonga ( Ethmalosa fimbriata) and mudskipper ( Periophthalmus koelreuteri) in Oron Local Government Area were evaluated for their content of heavy metals and the effects of salting on nutrient contents, oxidative stability and fatty acid profiles of smoke-dried fish cakes. Concentrations of heavy metals in edible muscle, liver and gill tissues were determined while the oxidative rancidities in unsalted and salted smoke-dried fish cakes, packed in low-density polyethylene (LDPE) bags and stored at 30 ± 1 °C were assessed using peroxide value (POV), thiobarbituric acid (TBA) value, free fatty acid (FFA) contents and sensory evaluation techniques. Generally the analytical data for Cu, Zn and Pb in the muscle, gills and liver of test samples were significantly low. Similarly, insignificant concentrations (<0.001 mg/100 g) of Hg, As, Cr and Cd were obtained in the fish tissues. The protein and lipid contents of the fish cakes ranged from 60.8–63.9% to 7.3–9.1%, respectively. Salting caused minimal reductions in the nutrient contents of the dried fish cakes. The POV, TBA, FFA and taste panel scores were highest during the first week of storage and declined thereafter. Salted smoke-dried samples had higher POV, TBA and FFA values than unsalted samples. Panel preference ratings for flavour/aroma and desirability characteristics of the fish cakes were in the order: C. nigrodigitatus > O. nilotichus > E. fimbriata > I. africana > P. keolreuteri. Palmitic acid (C16:0) was the predominant saturated fatty acid in the test samples. The eicosapentaenoic acid (EPA) contents of unsalted smoke-dried C. nigrodigitatus was 4.9%, Oreochromis niloticus 6.5%, Ilisha africana 2.6%, E. fimbriata 5.6% and P. koelreuteri 7.64%. The docosahexaenoic acid (DHA) contents of salted smoked dried fish were 1.8% ( C. nigrodigitatus), 4.8% ( O. niloticus), 9.5% ( I. africana), 5.5% ( E. fimbriata) and 12.3% ( P. koelreuteri).

Metal Concentrations, Foraging Distances, and Fledging Success of Great Blue Herons Nesting along the Hanford Reach of the Columbia River

An ecological risk assessment of the spatial distribution of metal concentrations along the Hanford Reach of the free-flowing Columbia River in southcentral Washington, identified great blue herons, Ardea herodias, at potential risk through the ingestion of contaminated riverine biota, especially fish. We measured metal concentrations in livers of pre-flight herons from the Hanford Reach and excrement samples taken from the same nests. Nests were distributed among three colonies situated upstream and downstream from nine retired plutonium production reactors along the river where metals in reactor coolant waters had been released directly into the river or disposed to shoreline retention basins and ditches. Distances traveled by parent herons to foraging areas along the river shore were determined by visually tracking parent birds as they flew from nests to upriver and downriver foraging sites. Foraging flight distances varied between colonies with mean distances ranging between 0.7 and 3.1 km. Cadmium, Cr, and Pb concentrations were higher in excrement than in the livers of pre-flight herons but the opposite was noted for Cu, Hg, and Zn. Highest metal concentrations of Cr, Cu, Zn, Cd, and Pb, were measured in excrement taken from heron nests at the colony located upstream from all reactors. These results were consistent with metal concentrations reported in river sediment from the same regions, indicating excrement from the heron nests may be a useful indicator of dietary uptake of metals by herons. Fledging success and eggshell thickness measurements were used as an index of health of the local heron population. The results indicate that the reproductive health of great blue herons nesting along the Hanford Reach is among the highest reported in the continental United States.

CONCENTRACIONES DE METALES PESADOS (PLOMO Y CADMIO) EN CONSERV AS DE ALMEJA, BERBERECHO Y NAVAJA COMERCIALIZADAS EN ESPAÑAHEAVY METAL (LEAD AND CADMIUM) CONCENTRATIONS IN TINNED CLAM, COMMON COCKLE AND RAZOR SHELL COMMERCIALIZED IN SPAINCONCENTRACIÓNS DE METAIS PESADOS (CHUMBO E CADMIO) EN CONSERV AS DE AMEIXA, BERBERECHO E NAVALLA COMERCIALIZADAS EN ESPAÑA

Tinned molluscs are specially affected by toxicological problems associated to heavy metal levels in foods, due to the filtrant capacity of these species. At the present work, concentrations of two heavy metals, lead and cadmium, in different tinned clam, common cockle and razor shell commercialized in Spain have been determined. Heavy metal concentrations in muscle, liver and liquid have been determined by means of dry digestion and anodic stripping voltammetry. Results have been statistically treated in order to evaluate the correlations between heavy metal content into the different established portions. With respect to lead, higher concentrations were quantified in liver samples (mainly those corresponding to common cockle), whereas for cadmium only razor shell samples showed a clear accumulation into liver. According to levels set by legislation, it has been established that heavy metal concentrations in tinned products do not constitute a risk for human health. © 2004 Altaga. All rights reserved. Resumen Las conservas de moluscos son especialmente sensibles a la problemática toxicológica causada por los metales pesados en los alimentos, por la capacidad filtrante de estos animales. En el presente estudio se han determinado los niveles de dos metales pesados, plomo y cadmio, en distintas conservas de almeja, berberecho y navaja, comercializadas en España. Empleando la digestión por vía seca, y por medio de una técnica de voltamperometría de redisolución anódica, se han analizado los niveles de ambos xenobióticos en el músculo y el hepatopáncreas de estos animales, así como en el líquido de cobertura. Los resultados han sido tratados estadísticamente para evaluar las posibles correlaciones en el contenido de metales en las distintas porciones anatómicas establecidas. Con respecto al plomo, destacan las mayores concentraciones alcanzadas en las muestras de hepatopáncreas (en especial para los berberechos), mientras que en el caso del cadmio esta distribución no ha sido tan homogénea, y tan sólo las navajas presentaron una tendencia acumuladora de este metal en el hepatopáncreas. De acuerdo a la legislación vigente se ha podido establecer que los niveles de metales pesados cuantificados no suponen riesgo para la salud del consumidor. © 2004 Altaga. Todos los derechos reservados. Palabras clave: Metal, plomo, cadmio, conserva, almeja, berberecho, navaja Resumo As conservas de moluscos son especialmente sensibles á problemática toxicolóxica causada polos metais pesados nos alimentos, pola capacidade filtrante destes animais. No presente estudio determináronse os niveis de dous metais pesados, chumbo e cadmio, en distintas conservas de ameixa, berberecho e navalla, comercializadas en España. Empregando a dixestión por vía seca, e por medio dunha técnica de voltamperometría de redisolución anódica, analizáronse os niveis de ámbolos dous xenobióticos no músculo e o hepatopáncreas destes animais, así coma no líquido de cobertura. Os resultados foron tratados estatísticamente para evaluar as posibles correlacións no contido de metais nas distintas porcións anatómicas establecidas. Con respecto ó chumbo, salientan as maiores concentracións acadadas polas mostras de hepatopáncreas (en especial para os berberechos), mentres que no caso do cadmio esta distribución non foi tan homoxénea, e tan só as navallas amosaron unha tendencia acumuladora dese metal no hepatopáncreas. Dacordo coa lexislación vixente puido establecerse que os niveis de metais pesados cuantificados non supoñen risco para a saúde do consumidor. © 2004 Altaga. Tódolos dereitos reservados. Palabras chave: Metal, chumbo, cadmio, conserva, ameixa, berberecho, navalla

Exposure to water from the lower Rhine induces a stress response in the rainbow trout Oncorhynchus mykiss.

The water quality of the river Rhine has improved in recent years and populations of salmonids are increasing. Nevertheless at present, the water from the lower Rhine still contains a complex mixture of low levels of many pollutants and it is not known whether exposure to such water is stressful to salmonid fish. For 31 days we continuously exposed the trout Oncorhynchus mykiss to water from the lower Rhine in the Netherlands and measured a variety of physiological, biochemical, and histological parameters, including the stress parameters cortisol and glucose. Exposure to Rhine water significantly increased cortisol and glucose after 3 h. At 21 and 31 days, cortisol was lower in exposed fish, indicating inhibition or exhaustion of the hypothalamic-pituitary-interrenal (HPI) axis. Electron microscopical analysis of the skin and gill epithelia revealed stressor-related effects that reflected disruption of the skin epithelium, the interface between the fish and the environment. This had little influence on hydromineral balance, as neither gill Na+/K+-ATPase activity nor plasma Na+ and Cl- were altered, although intestine- and kidney-specific Na+/K+-ATPase activities were affected. Analysis of heavy metal concentrations in the liver, kidney, and intestine indicated no bioaccumulation. Immunostimulation was reflected by increased respiratory burst activity of the head kidney leukocytes. From 7 days onwards, the body weight of the Rhine water fish was significantly lower than that of control fish. Overall, the data show that acute exposure to present day water from the lower Rhine induced a stress response in the fish that, during chronic exposure, was followed by impairment of the HPI axis, reduced growth, and prolonged immunostimulation.

Seasonal variations in tissue metabolic capacities of yellow perch (Perca flavescens) from clean and metal-contaminated environments

This study examined seasonal variations in tissue metal contamination and physiological condition of yellow perch (Perca flavescens) from a clean lake (Halfway Lake) and a metal-contaminated environment (Whitson Lake) in spring, summer, and fall of 1999. Dietary metal content influenced liver metal concentrations, especially for cadmium. Fulton's condition factor (FCF), an indicator of recent feeding activity, was lower in Whitson fish except in summer, when higher FCF values corresponded with higher liver copper concentrations, presumably because of higher feeding rate. Tissue protein concentrations and indicators of biosynthetic capacities (nucleoside diphosphate kinase and RNA/DNA ratios) suggested lower biosynthesis in Whitson fish. Muscle aerobic and anaerobic capacities (using citrate synthase and lactate dehydrogenase as indicators, respectively) were consistently lower in Whitson fish, with maximal differences in summer. In contrast, although liver aerobic capacities were generally comparable among populations, anaerobic capacities were much higher in Whitson fish. Finally, gill sodium/potassium adenosinetriphosphatase (Na+/K+ATPase) activity peaked in the spring in fish from both lakes, and higher activities were correlated with elevated gill copper concentrations. This study highlights the importance of seasonal variations in tissue metal concentrations and fish condition. This information is essential to evaluate the extent of impairment in condition faced by metal-contaminated wild fish.

Morphometric and metabolic indicators of metal stress in wild yellow perch (Perca flavescens) from Sudbury, Ontario: a review.

Eighteen lakes studied near Sudbury and across Northeastern Ontario (Canada) over a five-year period provided a wide contamination gradient of cadmium (Cd), copper (Cu) and other metals such as nickel (Ni) and zinc (Zn). All were inhabited by yellow perch (Perca flavescens), which was sometimes the only species present. Liver Cd and Cu concentrations were monitored in these lakes, in some cases for several consecutive years and for multiple seasons. This data suggests that yellow perch from clean to mildly-contaminated environments loosely control their hepatic Cu concentrations between 7 and 50 microg g dry weight(-1), and a threshold of 50 microg g dry weight(-1) is suggested as the normal range of homeostatic control. Similar data collected by others support this value. Liver Cd concentrations appeared more variable among lake samples, but consistently remained below 10 microg g dry weight(-1) in clean to mildly-contaminated lakes, also supported by data collected elsewhere. Condition factors allowed the discrimination between clean and polluted yellow perch, a conclusion consistent with data for the same species collected in the Rouyn-Noranda area (Quebec, Canada). Values of weight-to-length scaling coefficient lower than 3.0 also discriminated between clean and metal-polluted yellow perch. Finally, three studies indicated that chronic metal exposure can lead to an impairment of aerobic capacities in wild yellow perch, as indicated by lower muscle activity of citrate synthase (CS), aerobic swim performance and respiration rate. We propose that the combination of liver metal concentrations, scaling coefficient, condition factor and an indicator of physiological impairment such as muscle CS activity can provide a suitable range of parameters to adequately assess the effects of metal contamination on the health of yellow perch. Although yellow perch are ubiquitous in North America, this approach can potentially be applied to other small fish species more suitable to other study areas.

Seasonal variations in condition and liver metal concentrations of yellow perch ( Perca flavescens) from a metal-contaminated environment

The relationships between liver metal (Cu, Zn and Ni) concentration and physical condition of yellow perch ( Perca flavescens) were compared in fish sampled in five northeastern Ontario Lakes in the spring and seven lakes in the fall of 1997. These lakes represented a wide range of metal contamination, pH, dissolved organic carbon (DOC) and alkalinity. Lakes situated closest to emission point source had lower pH, alkalinity and DOC and higher aqueous metal concentrations than other lakes in this study. Fish from these lakes displayed higher liver metal concentrations. Seasonal variations in liver metal concentrations were observed in the most metal-contaminated lakes, with higher Cu levels in the spring and higher Zn and Ni concentrations in the fall. These fish had lower indicators of physical condition than fish from cleaner lakes. In particular, more metal-contaminated fish were smaller for a similar age, indicating slower growth rate, and had lower relative condition factor and scaling coefficients. The scaling coefficient is a descriptor of the growth pattern of fish, and higher values indicate increased weight gain per unit of growth in length. Negative ( P<0.05) relationships are reported between lake alkalinity and liver Cu concentration (in both seasons) and Zn concentration (in spring only). In both seasons mean liver Cu content was negatively associated ( P<0.05) with the scaling coefficient of the fish samples. With these data, we propose the use of the scaling coefficient as a simple biomonitoring tool to detect metal effects on the physical condition of yellow perch. Data presented here provide information on seasonal variations in liver metal concentration and condition of yellow perch that should be considered in the design of field studies investigating physiological effects of metals in wild fish. This work also describes a gradient of lake and fish metal contamination that is related to the physical condition of yellow perch. This system provides a unique research opportunity to further our limited knowledge of the effects of metals on the physiology of wild fish.

Cadmium and lead in selected tissues of two commercially important fish species from the Adriatic Sea

Baseline levels of cadmium and lead were determined in muscle tissue and liver of hake ( Merluccius merluccius) and red mullet ( Mullus barbatus), two commercially important fish species from the eastern Adriatic. Concentrations of trace metals in liver (Cd: 6–183 μg kg −1 w. wt. ; Pb: 39–970 μg kg −1 w. wt.) were within the range of recently published data for the Mediterranean. In the muscle tissue, cadmium concentrations (4.1–29 μg kg −1 w. wt.) were among the lowest reported values for the Mediterranean, whereas lead levels (49–158 μg kg −1 w. wt.) were within the range of values reported for various coastal areas of the Mediterranean. Presented data on cadmium and lead content in the studied fish species provide no proof of the general pollution of the Adriatic. Obtained data were tested in relation to fish length. Metal concentrations in liver decreased with the increase in fish size, whereas no significant correlation was found between trace metal levels in the muscle tissue and the length of both species. Relationships between metal concentrations and sex were also tested, but they gave no significant results. A comparison of contaminant concentrations in the edible tissue of hake and red mullet with the Croatian legislation shows that the consumption of their meat is not harmful for humans, not even for the most endangered population from the coastal region.

Heavy metals in soft tissues of Tursiops truncatus and Delphinus delphis from west Atlantic Ocean by X-ray spectrometry

In this work, the concentration of heavy metals in muscle, liver, fat tissue and skin is studied in 15 Delphinus delphis and two Tursiops truncatus dolphins, stranded along the Portuguese coast of the Atlantic Ocean. Sample collection was performed post-mortem and the tissues were kept frozen until analysed. Sample preparation included lyophilising and grounding in a Teflon mill to avoid contamination by metals. The obtained powder was prepared as pellets for each sample and analysed directly by X-ray fluorescence spectrometry. The concentrations of K, Ca, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Hg and Pb were obtained. Significant differences between the muscle, the skin and the fat tissues were detected. Cobalt concentrations were similar in liver, skin and muscle. The levels of Ni, Rb and Sr are at the level of the detection limit and whenever measurable are rather constant in all the analysed tissues. The results show that the highest concentrations of Mn, Cu and Hg are always in liver tissues. Zinc and Se concentrations are higher in skin and Pb is present in very low concentrations in all the analysed tissues except in skin; Fe and As are enhanced in muscle and liver. In general, the two studied species did not seem to differ significantly in their heavy metals concentration in a given tissue.

URBAN LAND-USE INFLUENCES ON TRANSPORT OF HEAVY METALS TO LAKES AND CONCENTRATIONS IN FISH

To investigate the urban land-useinfluences on transport of heavy metals to lakesand metal concentrations in fish liver (perch andcrucian carp), ten lakes in the Stockholm havebeen investigated. The catchment areacharacteristics have been studied in detail andput on a GIS-platform. The morphometry, waterquality and sedimentological characteristics ofthe lakes have been mapped and the metalconcentrations in water, sediments and fish liveranalysed. Evidently, metal concentrations in fishdepend on many internal characteristics relatedto the lake food-web and predation pressure,water chemistry (which influences metalpartitioning coefficients and hence pelagic andbenthic metal transport pathways), and lakemorphometry and hydrodynamics (which influencetransport patterns and internal loading).However, many of these causal agents regulatingmetal concentrations in water, sediments andfish, depend on catchment area characteristics.One aim of this paper has been to quantitativelyrank how the studied factors influence metalconcentrations in lake water and fish usingstatistical methods to find out how much of thevariability among the lakes that can bestatistically explained by these factors. Thisshould provide an interesting base for furtherstudies on the role of other factors, notaccounted for in this study, and about causalmechanisms. The results may also, hopefully, beused to address questions related to remedialmeasures – what can actually be done to reducemetal transport from urban areas to lakes, andmetal concentrations in fish, and what can beexpected from such remedies? Normed catchmentheavy metal loads to the lakes have beencalculated from models. Two-step regressionmodels consisting of catchment ‘size’ andcatchment ‘urban status’ parameters could explainlarge parts of the variations in the metal fluxesamong the lakes. These two main clusters of catchment variables are defined and motivated in this work. Cu was found to be the metal most dependenton ‘urban status’ followed by Cr. Pb had aboutequal influences from the ‘size’ as from theurban catchment ‘status’ variables. Cd, Hg, Niand Zn were more influenced by the ‘size’ than bythe ‘urban status’. For most metals,concentrations in fish liver were found to bemost correlated to general urbanity parametersand Cu and Pb to communications variables.

Trace metals in liver, skin and muscle of Lethrinus lentjan fish species in relation to body length and sex

A post-Gulf sea water pollution assessment program was carried out in the liver, skin and muscle tissues of the localized Lethrinus lentjan fish species [Family: Lethrinidae (Teleost)]. Monitoring the concentration of the major heavy metals at different sites along the western coast of the United Arab Emirates (UAE) on the Arabian Gulf was studied. The concentrations of Zn, Cu and Mn were found to follow the order: liver>skin>muscle while the cadmium level follows the sequence: liver>muscle>skin. The influence of fish sex and body length on the metal accumulation of those metals in the tested fish organs was critically investigated. The average metal concentrations in liver, skin and muscle of female fish were found to be higher than those found in the male fish. The detected metal levels were generally similar to previous pre-war, 1991 levels. The study concludes that the marine fish from the Arabian Gulf are comparatively clean and do not constitute a risk for human health.

Inhibition of soluble and microsomal epoxide hydrolase by zinc and other metals.

Inhibition of xenobiotic-metabolizing enzymes by metals may represent an important mechanism in regulating enzyme activity. Fourteen cations were evaluated for inhibition of microsomal epoxide hydrolase (mEH) (mouse, rat, and human liver), soluble epoxide hydrolase (sEH) (mouse, rat, and human liver), and recombinant potato sEH. Of the metals tested, Hg2+ and Zn2+ were the strongest inhibitors of mEH, while Cd2+ and Cu2+ were also strong inhibitors of sEH (I50 for all approximately 20 microM). Nickel (divalent) and Pb2+ were moderate inhibitors, but Al2+, Ba2+, Ca2+, Co2+, Fe2+, Fe3+, Mg2+, and Mn2+ were weak inhibitors of both mEH and sEH (less than 50% inhibition by 1 mM metal). Six anions (acetate, bromide, chloride, nitrate, perchlorate, and sulfate) were tested and found to have no effect on the inhibition of sEH or mEH by cations. The kinetics and type of inhibition for zinc inhibition of sEH and mEH were examined for mouse, rat, human, and potato. Zinc inhibits mEH in a competitive manner. Inhibition of human and potato sEH was noncompetitive, but interestingly, zinc inhibition of mouse sEH was very strong and uncompetitive. Inhibition by zinc could be reversed by adding EDTA to the incubation buffer. Additionally, mouse liver microsomes and cytosol were incubated with these chelators. Following incubation at 4 degrees C, samples were dialyzed to remove chelator. Both mEH and sEH activity recovered was greater in samples treated with chelator than in control incubations. Similar treatment with the protease inhibitor Nalpha-p-tosyl-L-lysine chloromethyl ketone (TLCK) did not affect enzyme activity recovered. During systemic inflammation, hepatic metallothionien is induced, and liver metal concentrations increase while serum metal concentrations are decreased. The inhibition of microsomal and soluble epoxide hydrolase by metals may represent a mechanism of down-regulation of enzyme activity during inflammation.

Metal Concentrations in Tissues of Rabbitfish ( Siganusoramin) Collected from Tolo Harbour and Victoria Harbour in Hong Kong

Rabbitfish ( Siganus oramin, also known as Siganus canaliculatus) samples were collected from different coastal sites in the Victoria Harbour and Tolo Harbour in the summer of 1997 for the analyses of metal (cadmium, copper, lead, and zinc) concentrations in liver, gills, and muscle. The overall metal concentrations in rabbitfish tissues were below regulatory levels implemented through the government of Hong Kong. For cadmium and lead, the metal concentrations detected were place concentrations here. Generally speaking, the metal concentrations in liver samples were higher than that of gills and muscle. However, the mean values of lead concentrations of rabbitfish from the Tolo Harbour and Victoria Harbour are higher in the gills than in the livers.

Effects of vitamin A pretreatment on nickel-induced lipid peroxidation and concentration of essential metals in liver, kidney and lung of mice.

In the present study we report the effects of pretreatment with large doses of vitamin A (Vit A, retinol) on hepatic, renal and pulmonary lipid peroxidation, and Ni and essential metal (Fe, Cu, Zn and Ca) concentrations in mice acutely exposed to nickel. Vitamin A (250,000 IU/kg per day) was administered by oral gavage to ICR mice for 7 days. On the 8th day, NiCl2 (5 mg Ni/kg body wt.) was injected i.p. to Vit A- or vehicle-pretreated mice. Vitamin A pretreatment alone did not alter lipid peroxidation in liver, kidney and lung. Lipid peroxidation in liver, kidney and lung was increased after treatment with NiCl2 alone. The extent of lipid peroxidation levels in Vit A + Ni treated mice was enhanced in liver, but reduced in kidney and lung. The Ni concentration in these three organs was below the detection limit (0.09 microg/g) in control and Vit A-pretreated mice. The accumulation of Ni in Vit A + Ni treated mice was increased in liver, but decreased in kidney and lung compared to Ni-treated mice. The concentrations of Fe, Cu, Zn and Ca in these organs were significantly increased in Ni-treated mice. In Vit A + Ni treated mice, compared to Ni-treated mice, hepatic Fe was significantly increased while Cu, Zn and Ca levels were reduced, but still higher than those of control and Vit A-treated mice. In the kidney of Vit A + Ni treated mice, the increase of Cu, Fe, and Zn but not Ca, was reduced and not significantly different from control and Vit A-treated mice. Pretreatment with Vit A reduced the increased Fe, Cu, Zn and Ca concentration in the lung caused by Ni injection. We therefore conclude that the effect of Vit A pretreatment on Ni toxicity is organ-dependent.

Trace metal concentrations in livers and kidneys of sea turtles from south-eastern Queensland, Australia

The concentrations of some or all of arsenic (As), cadmium (Cd), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the livers and kidneys of 50 stranded sea turtles (38 Chelonia mydas, eight Caretta caretta, three Eretmochelys imbricata, one Lepidochelys olivacea) from the Moreton Bay region of south-eastern Queensland, Australia. Concentrations of Cd, Se and Zn in the kidney tended to decrease with age, whereas concentrations of Zn in the liver tended to increase. Concentrations of Cd in all sea turtle species (1.7–75.9 µg g-1 wet weight) were amongst the highest recorded for marine vertebrates globally. Although there was no obvious association between metal concentrations and particular diseases in C. mydas, the high concentrations of Cd found in edible turtle tissues may pose a threat to the health of indigenous people whose diet includes C. mydas.

Effect of cadmium administration and aging on the concentration of essential metals in liver and kidney.

To investigate the changes in the concentration of essential metals in organs caused by exposure to cadmium (Cd) and by aging, Cd was administered subcutaneously in single doses of 0.3, 0.9 and 2.7 nig/kg to female rats 10 and 40 weeks of age. The animals were sacrificed on the 7th day after the administration. The concentration of Cd, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in the liver and the kidney was determined and the relations between the concentration of Cd and that of other metals were investigated.1) In 10-week-old rats, the amount of Cd accumulated in the liver and the kidney increased linearly with increasing doses of Cd, while in 40-week-old rats, suppressed accumulation of Cd in the liver and increased accumulation of Cd in the kidney were found after administration of the high dose.2) The concentration of Zn in the liver and the kidney both increased with increasing doses of Cd. There was no age-related difference.3) The concentration of Cu in the liver increased in the animals which received the intermediate and the high dose, irrespective of age. The concentration of Cu in the kidney showed no changes caused by Cd administration or by aging.4) The concentration of Fe in the liver increased in both 10-week-old and 40-week-old rats which received the high dose. The concentration was higher in 40-week-old rats than in 10-week-old rats. The Fe concentration in the kidney and the Mn concentration in the liver and the kidney was not affected by Cd administration or by aging.5) Discriminant analysis, by age, suggested that the amount of metals in the liver and the kidney was more likely to be affected by exposure to Cd in young individuals and less likely to be affected by exposure to Cd with the increase of age.

EFFECTS OF Zn-DTPA ON ESSENTIAL TRACE METALS IN RATS

Zn-DTPA was injected intraperitoneally into rats (30 µmol/kg) with a single dose or a daily dose for 10 consecutive days. Urine samples were collected for 24 hours after the single injection and tissue samples were excised 20 hours after the final of the consecutive injections. Elements in these samples were analyzed by PIXE. Zn-DTPA raised the urinary concentration of zinc and copper, and their urinary losses caused by Zn-DTPA were estimated to be 1.9 and 0.01 mg/30μmol Zn-DTPA, respectively. The concentration of metals in the liver, kidneys, brain and femurs remained unchanged. These results suggest that almost all of Zn-DTPA is excreted into the urine without replacement with other metals, and so this chelating agent may not induce any deficiencies of essential metals when animals are treated with a dose of 30 µmol/kg per day.