Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?
The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system.
Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz, Spain; Departamento Central De Investigación (DCI), Universidad Laica Eloy Alfaro de Manabí, Vía San Mateo, Manta, Ecuador. Electronic address: dayanara.macias@uleam.edu.ec.
Dayanara
D
Macías-Mayorga
Departamento de Física Aplicada, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz, Spain.
Irene
I
Laiz
Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz, Spain.
Ignacio
I
Moreno-Garrido
Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz, Spain.
Julián
J
Blasco
D000818:Animals; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D049896:Crassostrea / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation; D041981:Gastrointestinal Tract / Q000187:drug effects; D005880:Gills / Q000187:drug effects; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D008668:Metallothionein / Q000032:analysis / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity
D014874:Water Pollutants, Chemical; D002104:Cadmium; D008668:Metallothionein; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione
Crassostrea angulata; Enzymatic activity; Glutathione; Integrated biomarker response; Kinetics; Metallothionein