Trace metals in the marine bivalve Macoma balthica in the Westerschelde estuary, The Netherlands : Part 3 : Variability of the role of cytosol in metal uptake by the clams
Clams Macoma balthica have been sampled every two months for two and a half years in the Westerschelde estuary and submitted to in vitro exposure to Cd, Cu and Zn. Total and heat-stable cytosolic metal concentrations have been measured before and after exposure to study the effects of the season on the metal uptake by the bivalve. Much higher uptakes of Cd and, to a lesser extent, of Cu are observed in winter than in summer, while Zn appears to be constantly regulated. These phenomena are amplified in the cytosol, especially for the non-essential Cd for which the concentrations after exposure can reach 3.5-4 micrograms/grams (dry weight) in winter, but only a maximum of 0.5 micrograms/gram in summer, all natural values being between 0.01 and 0.1 micrograms/gram on average. The contents (micrograms) of the various elements, either at the total or at the cytosolic level, are not constant, hence showing that the body weight seasonal fluctuations of the clams are not the only parameter responsible for the metal uptake variability. Furthermore, it is shown that the proportion of cytosolic metal is not constant, but increases with the absolute cytosolic concentration up to 35-40 %. Therefore, the cytosolic phase of the cells plays a growing role in Cd, Cu and Zn storage as long as their total concentration increases.
Bibliographic Reference: Article: The Science of the Total Environment (1995)
Record Number: 199511308 / Last updated on: 1995-11-23
Original language: en
Available languages: en