Effects of sea water and stanniectomy on branchial Ca2+ handling and drinking rate in eel (Anguilla anguilla L.)

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Inland alkaline brackish water aquaculture of juvenile razor clam: survival, growth, physiology and immune responses

In this study, we investigated rearing and breeding razor clam (Sinonovacula constricta) in inland alkaline brackish water. During 45 days of the experiment in candidate target inland area brackish water (TBW), survival, growth, enzyme activity and immune responses were analysed. The results showed that shell length and weight were significantly inhibited in the TBW group (p <0.001). Although the cumulative mortality was 81.479 ± 7.028 (p < 0.001) at 15 days, it increased slowly to 92.915 ± 2.271 (p < 0.001) at 45 days. The enzyme activities of Na+/K+-ATPase, aspartate aminotransferase and superoxide dismutase peaked at 15 days, and juvenile S. constricta (JSC) may engaged in partial anaerobic metabolism or damage to gill tissue, which may explain the high mortality rate at this time. Additionally, the phagocytic ability of haemocytes was inhibited (p < 0.001), but the metabolic activity was enhanced (p < 0.001). This implies that 15 days was the peak of TBW stress, and stress gradually decreased by days 30 and 45. TBW affected metabolism, osmotic regulation, and immune responses. There was an independent ionic interaction perhaps effect on JSC, primarily through Na+/K+ rate. Approximately 7 % of animals adapted successfully to TBW after 45 days. In summary, S. constricta has a great potential in further anti-TBW conditions selective breeding research.info:eu-repo/semantics/publishedVersio

Histopathological alterations in Senegal sole, Solea Senegalensis, from a polluted Huelva estuary (SW, Spain)

As a component of a large research project to evaluate the effects of contaminants on fish health in the field, histopathological studies have been conducted to help establish causal relationship between pollutants (heavy metals and aromatic polycyclic hydrocarbons—PAHs) and histopathological responses in Senegal sole, Solea senegalensis, from an estuary of SW Spain. Heavy metals (As, Zn, Cd, Pb, Cu and Fe) and 16 PAHs (proprietary USEPA) concentrations in water, sediment and tissues (liver and gills) and histopathological alterations in S. senegalensis from three sampling sites of Ria de Huelva estuary during 2004–2006 years have been analysed. The histopathological studies revealed seasonal and spatial differences in the lesion grade of alterations observing the highest lesion grades in fish from Odiel River and autumn season. No significant differences were observed in the alterations prevalence between sampling sites, but significant differences were observed between seasons observing the highest prevalence in autumn season. However, calculated IPAT demonstrated a low–moderate impact of pollutants on health fish. Correlations between histopathological alterations and pollutants analysed were observed being heavy metals the group that presented a major number of correlations with alterations in several organs of S. senegalensis. In evaluating the general health of fish, the use of histopathological studies in recommended for making more reliable assessment of biochemical responses in fish exposed to a variety of environmental stressors. Statistical analysis using semiquantitative data on pathological lesions can help to establish correlation between cause (stressor) and effect (biomarker)

The effects of heavy metal cations and sulfhydryl reagents on degranulation from digitonin-permeabilized neutrophils

Digitonin-permeabilized neutrophils were exposed to micromolar levels of a variety of heavy metal cations and sulfhydryl oxidants to gain insight into the potential biochemical mechanisms underlying neutrophil degranulation. The results from this study suggest that the oxidation of intracellular sulfhydryl groups may play a role in neutrophil signal transduction. Evidence to support this conclusion is based on the observation that cupric phenanthroline and Cu2+/cysteine, agents reported to induce disulfide bond formation, evoke significant granule enzyme release when presented to permeabilized neutrophils. The stimulatory actions of these compounds occur in the absence of Ca2+ and are blocked by the sulfhydryl reducing agent, dithiothreitol. In addition, we observed marked potentiation of Ca2+-induced secretion by potentially physiological levels of Ni2+. Although we are unaware of any Ni2+-requiring enzymes in eukaryotic cells that are likely to be pertinent to degranulation, the ability of this divalent metal cation to lower the Ca2+ requirements for granule secretion suggests that it may play an important regulatory role in Ca2+-dependent processes. Finally, we observed significant granule release when permeabilized neutrophils were exposed to the heavy metal cations, Hg2+ and Ag+. The apparent stimulatory actions of these metals were the result of lysis rather than degranulation. Thus, the ability of these metals to lyse intracellular organelles such as lysosomal granules may contribute to their toxicological properties.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28020/1/0000456.pd

Behavioural and Physiological Responses of Gammarus pulex Exposed to Cadmium and Arsenate at Three Temperatures: Individual and Combined Effects

This study aimed at investigating both the individual and combined effects of cadmium (Cd) and arsenate (AsV) on the physiology and behaviour of the Crustacean Gammarus pulex at three temperatures (5, 10 and15°C). G. pulex was exposed during 96 h to (i) two [Cd] alone, (ii) two [AsV] alone, and (iii) four combinations of [Cd] and [AsV] to obtain a complete factorial plane. After exposure, survival, [AsV] or [Cd] in body tissues, behavioural (ventilatory and locomotor activities) and physiological responses (iono-regulation of [Na+] and [Cl−] in haemolymph) were examined. The interactive effects (antagonistic, additive or synergistic) of binary mixtures were evaluated for each tested temperature using a predictive model for the theoretically expected interactive effect of chemicals. In single metal exposure, both the internal metal concentration in body tissues and the mortality rate increased along metallic gradient concentration. Cd alone significantly impaired both [Na+] and [Cl−] while AsV alone had a weak impact only on [Cl−]. The behavioural responses of G. pulex declined with increasing metal concentration suggesting a reallocation of energy from behavioural responses to maintenance functions. The interaction between AsV and Cd was considered as ‘additive’ for all the tested binary mixtures and temperatures (except for the lowest combination at 10°C considered as “antagonistic”). In binary mixtures, the decrease in both ventilatory and locomotor activities and the decline in haemolymphatic [Cl−] were amplified when respectively compared to those observed with the same concentrations of AsV or Cd alone. However, the presence of AsV decreased the haemolymphatic [Na+] loss when G. pulex was exposed to the lowest Cd concentration. Finally, the observed physiological and behavioural effects (except ventilation) in G. pulex exposed to AsV and/or Cd were exacerbated under the highest temperature. The discussion encompasses both the toxicity mechanisms of these metals and their interaction with rising temperature

Cadmium inhibits plasma membrane calcium transport

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Cadmium inhibition of Ca2+ uptake in rainbow trout gills

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Kinetics of ATP- and Na+-gradient driven Ca2+ transport in basolateral membranes from gills of freshwater- and seawater-adapted tilapia

Contains fulltext : 10931.pdf (publisher's version ) (Open Access