Interactions between copper and cadmium modify metal organ distribution in mature tilapia, Oreochromis mossambicus

Abstract

Sexually mature female tilapia were exposed to sublethal concentrations of waterborne Cu and/or Cd over 6 days, and

Cu Accumulation and Elimination in the Tissues of the Olive Flounder Paralichthys olivaceus

“…These authors proposed two hypotheses for their results: (a) there may be secondary Cu uptake from Cu excreted from the bile into the intestine, or (b) the intestine may serve as a possible excretion route for the metal (Mazon and Femandes, 1999). Pelgrom et al (1995) also observed similar results in tilapia exposed for 6 and 11 days to 20 and 100 µg/L Cu. Moreover, higher Cu concentrations in the intestines may be related to the fact that marine teleosts exhibit higher drinking rates than freshwater teleosts (Jobling, 1995).…”

“…These results support the hypothesis that the liver is the major storage and regulatory tissue involved in Cu homeostasis. Similar results have been observed in sea bream (Wong et al, 1999), rainbow trout (Handy, 1993;Miller et al, 1993), tilapia (Pelgrom et al, 1995;Ay et al, 1999), and the Senegales sole (Arellano et al, 1999). Therefore, after Cu exposure, the liver of olive flounder is clearly a more important storage tissue than other tissues.…”

“…However, Cu accumulation in the gills of olive flounder was lower than in the liver and intestines. Similar results have also been observed in rainbow trout (Miller et al, 1993;McGeer et al, 2000b), tilapia (Pelgrom et al, 1995), Senegales sole (Arellano et al, 1999), and sea bream (Wong et al, 1999). Mazon and Femandes (1999) suggested that these results were attributable to continuous Cu regulation, during which the gills absorb Cu and subsequently transfer it into the bloodstream.…”

“…Generally, the kidneys play a major role in the detoxification and excretion of toxins via the induction of metal-binding proteins such as MT (Roesijadi and Robinson, 1994), similar to the liver. Therefore, tissues such as the kidneys, which are major producers of MT, show high accumulation of Cu in fish (Pelgrom et al, 1995;Mazon and Femandes, 1999;McGeer et al, 2000b). However, Cu accumulation in the kidney of flounder was about an order of magnitude lower than in the intestine and liver.…”

“…Moreover, tissue-specific accumulation of metals may be a key indicator of chronic exposure (Bergman and Dorward-King, 1997). Although the subchronic toxic effects of Cu on fish are well documented, studies have primarily focused on freshwater fish (Pelgrom et al, 1995;Marr et al, 1996;De Boeck et al, 1997;Mazon and Femandes, 1999;McGeer et al, 2000a), whereas few studies have examined the effects of Cu on marine fishes. Therefore, the kinetics of Cu accumulation in fish tissues are of great importance, particularly for marine fish.…”