Accumulation, transformation and tissue distribution of domoic acid, the amnesic shellfish poisoning toxin, in the common cuttlefish, Sepia officinalis

Domoic acid (DA) is a phycotoxin produced by some diatoms, mainly from the Pseudo-nitzschia genus, and has been detected throughout the marine food web. Although DA has been frequently found in cephalopod prey such as crustaceans and fish, little is known about DA accumulation in these molluscs. This study presents the first data showing relevant concentrations of DA detected in the common cuttlefish, Sepia officinalis, which is one of the most studied cephalopod species in the world. Domoic acid was consistently found throughout 2003 and 2004 in the digestive gland of cuttlefish reaching concentrations of 241.7 microg DA g(-1). The highest DA values were detected during spring and summer months, periods when Pseudo-nitzschia occur in the plankton. In fact, Pseudo-nitzschia blooms preceded the highest DA concentrations in cuttlefish. Evaluation of DA tissue distribution showed elevated DA concentrations in the digestive gland and branchial hearts. Further, DA isomers comprised a relevant percentage of the toxin profile, indicating degradation and biotransformation of the toxin in the branchial hearts. The common cuttlefish, like other cephalopod species, plays a central position in the food web and might be a new DA vector to top predators like marine mammals. Human intoxications are not expected since DA was only seldom detected in the mantle and even then in very low levels (max 0.7 microg DA g(-1)). However, in some countries whole juvenile animals are consumed (i.e. without evisceration) and in this case they might represent a risk to human health. This study contributes to understanding the occurrence of phycotoxins in cephalopods and reveals a new member of the marine food web able to accumulate DA.     

Heavy metal (Pb,Cu, Zn,and Cd) concentrations in the water and muscle of common carp (Cyprinus carpio) fish and associated non-carcinogenic risk assessment: Alagol wetland in the Golestan,Iran

Short- and long-term exposure to heavy metals can be dangerous for human health. One of the main routes of exposure to heavy metals is intake of seafood such as fish. In this study, lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd) concentration in the water and muscle of C. Carpio fish was measured and non-carcinogenic risk of these heavy metals was estimated. The mean (range) concentrations of Cu, Zn, Pb, and Cd were 7.92?±?7.99 (1.22–39.43?mg/kg), 120.90?±?106.25 (1.15–477?mg/kg), 5.84?±?5.22 (ND-21.86?mg/kg), and 0.027?±?0.043 (ND-0.14). Except Cd, the concentrations of Cu, Zn, and Pb were significantly more than Food and Agricultural Organization United Nations (FAOUN) maximum guidelines (p??Cu?>?Pb?>?Cd in the water and muscle tissue of C. carpio fish. Lowest and highest target hazard quotient (THQ) for adults was related to Cd (0.005) and Pb (0.252) and for children, Cd (0.003) and Pb (0.168), respectively. The rank order of THQ for adults and children are Pb?>?Zn?>?Cu?>?Cd. Since THQ and hazard index (HI) for both adults and children were significantly lower than 1 (p?C. Carpio fish consumption.     

Persistent organic pollutants and heavy metals in typical seafoods consumed in Singapore

In this study, the levels of several heavy metals and persistent organic pollutants (POPs) were measured in the edible portions of 20 different seafood types consumed in Singapore (2 < n < 12). The mean heavy metal concentrations among the seafood types ranged from below detection limits (BLD) to 14.2 microg/g wet weight (ww) for As (shark), to 0.50 microg/g ww for Cd (kunning), to 25.5 microg/g ww for Cu (gray prawn), to 0.58 microg/g ww for Hg (eel), and to 1.21 microg/g ww for Pb (salmon). Chlordane, polychlorinated biphenyls (PCBs), and p, p'-DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and its related metabolites (sum noted as DDTs) were the main POPs found among the seafood types, with highest concentrations in salmon fillets and green mussels. Polybrominated diphenyl ether (PBDE) concentrations in salmon fillets (2.75 ng/g ww) were one order of magnitude lower than the highest concentration of PCBs (28.5 ng/g ww). The mean daily intake of contaminants from seafood was calculated for the general population of Singapore. Daily intakes of heavy metals and POPs from seafood are below the oral reference dose set by the U.S. Food and Drug Administration (FDA), except for As, although our study did not characterize the species of As present. Daily intake of As, DDTs, heptachlor, and PCBs in seafood exceeded the conservative cancer benchmark concentrations set by the U.S. Environmental Protection Agency (EPA), suggesting that a significant number of people are potentially at risk in Singapore over a lifetime from seafood consumption.     

Renal and hepatic accumulation of cadmium and lead in the expression of CYP4F2 and CYP2E1

The present study examined accumulation of the metal toxins cadmium (Cd) and lead (Pb) in relation to the abundance of cytochrome P450 4F2 (CYP4F2), CYP2E1 and concentrations of zinc and copper in liver and kidney samples using immunoblotting coupled with metal analysis. The post mortem liver and kidney cortex samples were from 23 males and 8 females aged 3-89 years. All were Caucasians who had not been exposed to metals in the workplace. Average kidney cortex Cd load of 17.4 microg/g w.w. was 17 times greater than average liver Cd load (1.1 microg/g w.w.). In contrast, average kidney cortex Pb load of 0.09 microg/g w.w. was two times lower than liver Pb load of 0.19 microg/g w.w. Average Zn and Cu concentrations in the kidney cortex samples were 67% and 33% lower than those in the liver. Liver and kidney Cd loads, but not liver or kidney Pb loads, correlated positively with donors' age. After controlling for liver Cd load, an inverse correlation was seen between Zn and age (partial r=-0.39, P=0.02), suggesting reduction in liver Zn levels in old age. Liver CYP2E1 protein abundance correlated with age-adjusted Cd load (partial r=0.37, P=0.02) whereas kidney CYP4F2 protein abundance showed a positive correlation with age-adjusted Cd loads (partial r=0.40, P=0.02). These findings suggest that Cd may be an inducer of renal CYP4F2 and hepatic CYP2E1 and that increased renal CYP4F2 expression may implicate in Cd-linked renal tubular dysfunction and high blood pressure, involving CYP4F2-dependent arachidonic acid metabolism.     

Bioaccumulation of cadmium in an experimental aquatic food chain involving phytoplankton (Chlorella vulgaris), zooplankton (Moina macrocopa), and the predatory catfish Clarias macrocephalus x C. gariepinus

The accumulation of cadmium (Cd) was studied in an experimental aquatic food chain involving the phytoplankton Chlorella vulgaris as the primary producer, the zooplankton Moina macrocopa as the primary consumer, and the catfish Clarias macrocephalus x Clarias gariepinus as the secondary consumer. C. vulgaris was first exposed to Cd solutions at 0.00, 0.35, and 3.50 mg l(-1), referred to as control group and experimental groups 1 and 2, respectively. Subsequently, each group was fed to three corresponding groups of M. macrocopa. Finally, three groups of catfish were fed these corresponding groups of M. macrocopa. After C. vulgaris was exposed to 3.50 mg l(-1) Cd (experimental group 2), the residual Cd in solution was only 4.01 microg l(-1), lower than the maximum allowable limit of Cd in natural water sources (5 microg l(-1)). Cd concentrations in C. vulgaris were 0.01+/-0.00 microg g(-1) (dry wt) in the control group, 194+/-1.80 microg g(-1) (dry wt) in experimental group 1, and 1140+/-20.06 microg g(-1) (dry wt) in experimental group 2. The Cd concentrations in M. macrocopa were 0.01+/-0.00 microg g(-1) (dry wt) in the control group, 16.48+/-2.23 microg g(-1) (dry wt) in experimental group 1, and 56.6+/-3.23 microg g(-1) (dry wt) in experimental group 2. The Cd concentrations in catfish muscle increased with increasing Cd concentrations in the food. After 60 days of fish culture, the mean concentrations of Cd in fish muscle were 0.01+/-0.00 microg g(-1) (dry wt) in the control group, 0.61+/-0.02 microg g(-1) (dry wt) in experimental group 1 and 1.04+/-0.06 microg g(-1) (dry wt) in experimental group 2. Cd concentration in fish muscle of experimental group 2 was equal to the permissible limit. Cd accumulation affected fish growth: at the end of the study, the mean fresh weight (12.81 g) of catfish in the control group, was significantly higher than those experimental group 1 (10.43 g) and experimental group 2 (10.00 g). The results showed that the measurement of Cd concentration in water does not necessarily give a measure of the safety of aquatic organisms as human food. Hence, heavy metal contamination is a matter for concern when organisms are harvested, for fish and human consumption, from natural water sources.     

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman,Turkey

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (< 0.05 and 0.1 microg/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as microg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulation's residue limits, the cadmium level determined in fish tissues was high (0.1 microg/g) and the lead level, especially in liver tissue, was high in August (1 microg/g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.     

Estimation of the dietary intake of cadmium, lead, mercury, and arsenic by the population of Santiago (Chile) using a Total Diet Study.

Dietary intake of arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) by the population of Santiago (Chile) was determined using a Total Diet Study in the market basket modality. After conducting a survey of the foods consumed in the last 24 h, the most consumed food products were included in the basket. Subsequently, they were cooked or prepared according to typical Chilean procedures and grouped into 17 food categories according to their chemical characteristics. The fish and shellfish group had the highest contents of As (1351 ng/g wet weight, ww), Cd (277 ng/g ww), and Hg (48 ng/g ww), while the sugar group had the highest content of Pb (251 ng/g ww). For a person with a body weight of 68 kg, the dietary intakes of As (77 microg/day), Cd (20 microg/day), Hg (5 microg/day), and Pb (206 microg/day) are lower than the provisional tolerable weekly intake values established by the FAO/WHO. Consequently, the total intakes of As, Cd, Hg, and Pb in Santiago (Chile) are within the limits estimated as safe.     

The effects of long-term cadmium exposure on the growth and survival of juvenile bull trout (Salvelinus confluentus)

Bull trout (Salvelinus confluentus) have been listed recently as threatened in the United States under the federal Endangered Species Act. This species currently resides, or historically resided, in several waterways that either are impacted or are under threat of impact from metals mining activities. We conducted a 55-day sub-chronic (i.e. sublethal) cadmium (Cd) exposure in water at 30 mg l(-1) (as CaCO(3)) hardness, pH 7.5, and 8 degrees C. Exposures were conducted using six replicate exposure tanks for each of the six treatments (five Cd concentrations and one control). Measured Cd concentrations were <0.013 (control), 0.052, 0.089, 0.197, 0.383, and 0.786 microg Cd l(-1). Exposure to 0.786 microg Cd l(-1) caused increased mortality (37%) and reduced growth (28% reduction in weight change) in fish exposed for 55 days. All Cd exposure concentrations caused significant whole body accumulation of Cd compared with controls. Our results indicate that even though fish are significantly accumulating Cd in each non-control treatment, growth reductions in bull trout occurred only at Cd concentrations that also caused significant mortality. The Cd concentration that reduced growth and survival in this long-term exposure (0.786 microg Cd l(-1)) is greater than the recently-revised US federal aquatic life criteria (ALC) value for the corresponding hardness concentration (ALC=0.62 microg Cd l(-1) for acute effects and 0.11 microg Cd l(-1) for chronic effects).     

Relationship between exposure duration,tissue residues,growth, and mortality in rainbow trout (Oncorhynchus mykiss) juveniles sub-chronically exposed to copper

We conducted a 56-day sub-chronic test on the effects of Cu on rainbow trout (Oncorhynchus mykiss) fry at a nominal water hardness of 100 mg l(-1) (as CaCO(3)). Response measures were growth, whole body Cu concentrations, and mortality. Significant mortality was observed in fish exposed to 54.1 microg Cu l(-1) (47.8%) and 35.7 microg Cu l(-1) (11.7%). Growth was dose-dependent over the range of Cu treatments (0-54 microg Cu l(-1)), and was modeled as a function of Cu exposure concentration and exposure duration. Calculated inhibition concentrations (based on change in wet weight through a 56-day Cu exposure) were IC(50)=54.0 microg Cu l(-1), IC(20)=21.6 microg Cu l(-1), IC(10)=10.8 microg Cu l(-1), and IC(01)=1.1 microg Cu l(-1). Measured whole body Cu was also dose-dependent, and growth of trout fry was readily modeled as a function of tissue Cu and exposure duration. This model was virtually identical to a model previously developed for rainbow trout exposed to Cu at a hardness of 25 mg l(-1). Following the 56-day exposure period, we performed a 96-h acute challenge to Cu and Cd to evaluate the effects of Cu acclimation on acute Cu and Cd toxicity. Sensitivity to Cu was dependent on the 'acclimation dose'; trout previously held in control aquaria (i.e. not acclimated to Cu) suffered over 80% mortality, whereas trout previously exposed to 35.7 microg Cu l(-1) for 56 day suffered 20% mortality. These fish also showed somewhat reduced sensitivity to Cd, suggesting acclimation to Cu can enhance tolerance to other metals. Finally, the relationship between growth response and hardness (derived from several studies) appeared to have a different slope than the hardness relationship previously observed for lethality responses.     

Bioaccumulation of trace metals in the copepod Calanoides acutus from the Weddell Sea (Antarctica): comparison of two-compartment and hyperbolic toxicokinetic models

Bioaccumulation of Cd, Co, Cu, Ni, Pb and Zn in the Antarctic calanoid copepod Calanoides acutus (Giesbrecht, 1902) was investigated during a cruise of RV 'Polarstern' to the Weddell Sea. Main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. Except for Cd, the organisms accumulated metals upon exposure. It was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic uptake study. The model verification was extended in a third uptake study with increasing external metal dosing. We found a linear increase of net uptake with external waterborne metal exposures up to 80 microg Pb l(-1), with excellent predictions of the two-compartment model. For Co both models give reasonable predictions up to 20 microg Co l(-1). Regarding Cu, Ni and Zn only hyperbolic model predictions were in good agreement with measured values up to 150 microg Cu l(-1), 80 microg Ni l(-1) and 290 microg Zn l(-1). Due to a decrease of Cd body burden in the experiments, only the hyperbolic model was applicable, leading to reliable predictions up to 20 microg Cd l(-1). These concentrations largely determine the range for which these models may serve as a predictive tool.     

Anti-estrogen prevents xenoestrogen-induced testicular pathology of eelpout (Zoarces viviparus)

Estrogenic alkylphenols have been shown to affect the reproductive system of male fish causing induction of vitellogenin synthesis and altered testis structure. However, it is still unknown whether the histopathological effects on the testes is mediated by the estrogen receptor or if it represent general toxicopathological effects. In the present study, the effects of different concentrations of the estrogenic chemical 4-tert-octylphenol on vitellogenin (Vtg) synthesis and testicular structure were investigated in the eelpout Zoarces viviparus during spermatogenesis. Adult male eelpout were exposed to 4-tOP (nominal concentrations: 10, 50 or 100 microg l(-1)) or 17beta-estradiol (E2; 0.5 microg l(-1)) in a continuous flow-through system for 3 weeks. A group of fish were exposed to 4-tOP (50 microg l(-1)) concomitantly with the anti-estrogen ZM 189,154 (20 microg g(-1) week(-1), i.p.). The Vtg concentration in plasma was measured by enzyme-linked immunosorbent assay. The testicular structure was examined by light microscopy and gamma-glutamyl transpeptidase (gamma-GTP) activity was measured in the testes. The testicular localization of gamma-GTP was analysed by enzyme histochemistry. A marked increase in the plasma Vtg concentration was observed after exposure to the actual concentration of 35 microg l(-1) 4-tOP (nominal concentration, 50 microg l(-1)), 63 microg l(-1) 4-tOP (nominal concentration, 100 microg l(-1)) or E2. Co-treatment with ZM 189,154 totally abolished the 4-tOP-dependent induction of Vtg synthesis. Exposure to 4-tOP or E2 caused a marked reduction in the testis mass and severely affected the testicular development and structure including the Sertoli cells (based on histology and gamma-GTP activity), resulting in impairment of spermatogenesis and degeneration of lobular structures. Other cellular abnormalities such as accumulations of yellowish-brown pigmented cells and increased interstitial fibrosis in the testes was also observed in the exposed fish. In the groups exposed to the nominal concentrations of 50 or 100 microg l(-1) all fish had severely affected testes, while both normal, moderately and severely affected testes were found in the group exposed to the nominal concentration of 10 microg l(-1). Co-treatment with ZM 189,154 abolished part of these 4-tOP-induced effects on the testicular growth and histological structure. The study demonstrates that an anti-estrogen can abolish effects on the testis caused by estrogenic chemicals, providing evidence that some of the effects are mediated by the estrogen receptor.     

Bioaccumulation of trace metals in the Antarctic amphipod Paramoera walkeri (Stebbing, 1906): comparison of two-compartment and hyperbolic toxicokinetic models

Bioaccumulation of Cd, Pb, Cu and Zn in the Antarctic gammaridean amphipod Paramoera walkeri (Stebbing, 1906) was investigated at Casey station (Australian Antarctic Territory). The main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. The organisms accumulated metals upon exposure and it was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic study. However, the application of hyperbolic models appears to be more promising as a predictive tool for metals in amphipods compared to compartment models, which have failed to adequately predict metal accumulation in experiments with increasing external exposures in previous studies. The following kinetic bioconcentration factors (BCFs) for the theoretical equilibrium were determined: 150-630 (Cd), 1600-7000 (Pb), 1700-3800 (Cu) and 670-2400 (Zn). We find decreasing BCFs with increasing external metal dosing but similar results for treatments with and without natural UV radiation and for the combined effect of different exposure regimes (single versus multiple metal exposure) and/or the amphipod collective involved (Beall versus Denison Island). A tentative estimation showed the following sequence of sensitivity of P. walkeri to an increase of soluble metal exposure: 0.2-3.0 microg Cd l(-1), 0.12-0.25 microg Pb l(-1), 0.9-3.0 microg Cu l(-1) and 9-26 microg Zn l(-1). Thus, the amphipod investigated proved to be more sensitive as biomonitor compared to gammarids from German coastal waters (with the exception of Cd) and to copepods from the Weddell Sea inferred from literature data.     

Comparative study of bioconcentration and EROD activity induction in the Japanese flounder, red sea bream, and Java medaka exposed to polycyclic aromatic hydrocarbons

Japanese flounder (Paralichthys olivaceus), red sea bream (Pagrus major), and Java medaka (Oryzias javanicus) were exposed to water borne polycyclic aromatic hydrocarbons (PAHs) for 10 days to compare PAH bioconcentration and P450 enzyme induction by ethoxyresorufin-O-deethylase (EROD) activity for use in oil spill biomonitoring in Asian waters. Target exposure concentration for phenanthrene, pyrene, and chrysene were 30 microg/L each, while benzo[a]pyrene was 3.0 microg/L. Phenanthrene and pyrene were accumulated in the flounder and red sea bream; chrysene was found only in the livers of the red sea bream, while Java medaka accumulated the high molecular weight benzo[a]pyrene along with the other PAHs. Total PAH concentrations increased with duration of exposure in the red sea bream from 184+/-37 ng/g wet weight (w.w.) in day 2 to 572+/-72 ng/g (w.w.) in day 10; It, however, decreased in the other two species. Among the three fish species, Java medaka had the highest initial total PAH concentration of 388+/-62 ng/g (w.w.); this was, however, reduced to the lowest final concentration of 52.3+/-3 ng/g (w.w.). It also had the highest EROD activity of 4.2+/-2.8 n mol/min/mg protein compared to the lowest of 0.11+/-0.03 n mol/min/mg protein in the Japanese flounder. Java medaka with high EROD activity induction and bioaccumulation of all PAHs will be suitable for PAH biomonitoring in Asian waters. Due to its high PAH bioconcentration red sea bream is also recommended for consideration for biomonitoring and PAH chronic toxicity tests.     

Bioaccumulation of trace metals in the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea

The objective of the present study is to evaluate the suitability of the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea as a biomonitor for the trace metals Cd, Pb, Cu, and Zn and to analyse whether the two-compartment model sensu OECD could be used as a predictive tool to assess environmental quality. The tested decapods accumulated Cd and Pb upon exposure and it was possible to estimate significant model parameters of two-compartment models, while they did not respond to waterborn Cu and Zn. Kinetic BCFs at theoretical equilibrium were 860 for Cd and 750 for Pb. A tentative estimation showed the following sensitivity of C. crangon to an increase of soluble metal exposure: 0.4 microg Cd l(-1) and 0.9 microg Pb l(-1). Available information can be used to quantify a measure of agreement or disagreement between bioaccumulation in various decapods. This can be regarded as an important step in the calibration of biomonitors, which is necessary to assess the potential for bioaccumulation on different temporal and geographical scales.     

Effect of smoking on cadmium and lead concentrations in human amniotic fluid

The amniotic fluids of 155 pregnant women, non-smokers (n = 128) and smokers (n = 27), were investigated on their cadmium (Cd) and lead (Pb) concentrations. The mean +/- s range of Cd in the amniotic fluid of non-smokers amounted to 2.58 +/- 1.36 ng/l, that of smokers to 7.29 +/- 2.39 micrograms/l. Moreover, there was a correlation between the extent of daily cigarette consumption and Cd levels. With Pb, higher concentrations were found ranging between 23.98 +/- 9.41 ng/l for non-smokers and 21.53 +/- 7.16 micrograms/l for smokers. No correlations were seen between age, week of pregnancy, blood pressure, disorders of pregnancy and the amniotic Cd or Pb concentrations. Thus, the maternal and fetal risks of the higher Cd levels in the amniotic fluid of smoking women remain unanswered.     

Observations on the interaction of zinc and cadmium uptake rates in crustaceans (amphipods and crabs) from coastal sites in UK and France differentially enriched with trace metals

This paper presents results on the possible interaction of zinc and cadmium uptake rates in crustaceans. Zn and Cd uptake rates were measured in amphipods (Orchestia gammarellus) and crabs (Carcinus maenas and Pachygrapsus marmoratus) from five coastal sites in Britain and France subjected to different degrees of trace metal enrichment. The presence or absence of 100 μg l(-1) of one metal (1.53 μM l(-1) Zn, 0.89 μM l(-1) Cd) had an inconsistent effect on the rate of uptake of the other metal by O. gammarellus. The presence or absence of 50 μg l(-1) of either zinc (0.76 μM l(-1)) or cadmium (0.45 μM l(-1)) had no effect on the rate of uptake of the other metal by C. maenas (from Millport, Scotland). Zinc and cadmium uptake rates were correlated in individual amphipods and crabs of both species from the five sites. These correlations indicate that zinc and cadmium might share common routes of uptake from solution by crustaceans, but the metals do not consistently interact competitively or synergistically at the exposure concentrations investigated. Regression coefficients of the relationship between zinc and cadmium uptake rates in amphipods and crabs showed occasional, but inconsistent, differences between sites and over time. All three crustaceans take up zinc from solution at a higher rate than cadmium for the same total dissolved metal molar concentration, but at a lower rate than cadmium per free metal ion molar concentration.     

Effects of CP-99, 994, a tachykinin NK(1) receptor antagonist, on abdominal afferent vagal activity in ferrets: evidence for involvement of NK(1) and 5-HT(3) receptors.

The effect of CP-99, 994, a tachykinin NK(1) receptor antagonist, on abdominal vagal afferent nerve activity in the ferret was investigated. Substance P (1 microg/kg, i.v.) increased vagal afferent activity by 449.0+/-51.9% and this was reduced to 145.9+/-5.7% (p<0.01) by pre-treatment with CP-99, 994 (1 mg/kg, i.v.), and to 149.5+/-1.5% (p<0.001) by granisetron (1 mg/kg, i.v.), a 5-HT(3) receptor antagonist. In addition, the increase in vagal nerve activity induced by 5-HT (25 microg/kg, i.v., 552.0+/-57.0% increase from pre-injection level) was significantly reduced (401.3+/-10.6% increase from pre-injection level, p<0.05) by CP-99, 994 (100 microg/kg, i.v.). These results provide evidence for an involvement of peripheral NK(1) and 5-HT(3) receptors in substance P-induced vagal afferent activation. While the functional consequences (if any) of such peripheral effects were not investigated, they could contribute either directly (e.g. by blockade of receptors on vagal afferents) or indirectly (e.g. modulation of 5-HT release or reduction of local inflammatory response) to the antiemetic effects of CP-99, 994 against cisplatin and other emetic agents acting primarily via the vagus.     

Intake of chemical contaminants through fish and seafood consumption by children of Catalonia, Spain: health risks.

The intake of arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenylethers (PBDEs), polychlorinated diphenylethers (PCDEs), hexachlorobenzene, and polycyclic aromatic hydrocarbons through fish and seafood consumption by children of Catalonia, Spain, was assessed. In 2005, samples of the 14 most consumed marine species in Catalonia were randomly acquired in various cities of the country. Analysis of the above chemical contaminants were determined according to the appropriate analytical techniques and the daily intakes were estimated. For most pollutants, intake was higher in boys than in girls. Average exposure of children to contaminants through fish and seafood consumption did not exceed the respective tolerable daily intake of those pollutants for which it has been already established (metals, PCDD/Fs plus dioxin-like PCBs, HCB, and PAHs). In relation to body weight, intake by children of most contaminants was higher than that found for other age groups of the general population of Catalonia.     

Human exposure to PCDD/Fs and PCBs through consumption of fish and seafood in Catalonia (Spain): Temporal trend

The concentrations of PCDD/Fs and 18 PCBs (DL- and NDL-) were analyzed in 16 fish and seafood species widely consumed in Catalonia (Spain). The exposure of these pollutants was subsequently estimated according to various groups of population. The concentrations of PCDD/Fs and PCBs showed an important decrease in relation to the baseline study (2000) and our last survey (2008). Sardine and red mullet were the species showing the highest pollutant concentrations, while canned tuna and cuttlefish presented the lowest levels. Sardine was the main contributor to the exposure of PCDD/Fs and PCBs. In contrast, swordfish was the species with the lowest contribution to the exposure of PCDD/Fs, DL-PCBs, and PCDD/Fs+DL-PCBs, while clam was the minor contributor for NDL-PCBs and total PCBs. For all groups of population, the current intakes of PCDD/Fs and PCBs were lower than the TDI (1–4 pg WHO-TEQ/kg body weight/day), being children the group with the highest exposure. However, this exposure should not mean a health risk for this group of population. The current intake of PCDD/Fs and PCBs through fish and seafood consumption was similar or even lower than most values reported in recent studies all over the world.