Abstract

LEMUS, Mairin; EUCARIS, Evaristo; SALAZAR-LUGO, Raquel  and  CHUNG, Kyung. Modulation of metallothionein synthesis in perna viridis pre exposed to copper and exposed to cadmium. Saber [online]. 2014, vol.26, n.1, pp.10-17. ISSN 1315-0162.

The metallothioneins (Mts) have been used as biomarkers because toxic metals such as Hg, Cd, Cu can induce their synthesis; however, environmental factors and the presence of other xenobiotics can determine the magnitude of the response in future exposures to metal ions. Metallothionein concentration was determinate in the soft tissue of Perna viridis juveniles pre-exposed to Cu and exposed to Cd (Cu/Cd) for 21 days. For this, three experimental groups were established: exposed to Cd, pre-exposed to Cu and exposed to Cd and the control group (no metal). Cadmium accumulation in tissues of P. viridis was significantly higher in pre-exposed organisms to Cu, with an average value of 6.6 ± 1.9 mg/g, while in those exposed to Cd, was 4.7 ± 2.4 mg/g. Mts concentrations were also higher in the Cu/Cd experimental group, with a value of 1.36 ± 0.52 mg/g in relation to those exposed to Cd which had a value of 0.79 ± 0.47 mg/g. The relationship between Mts and bioaccumulation of Cd was significant in the group exposed to Cd, but not in the exposed Cu/Cd. These results suggest that Cu possibly acted as an inducer of Mts in the body, which led to increased accumulation of Cd in P. viridis and increase in Mts concentration. Tolerance and bioaccumulation of Cd in P. viridis was determined by previous exposure of the organism and hence its response on levels of MTs also depends on it.

Keywords : Cu; Cd; bivalve; metal toxicity.

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