Determination of Cadmium–Metallothioneins in Zebra Mussels Exposed to Subchronic Concentrations of Cd2

• Published in: Ecotoxicology and environmental safety Vol. 33; no. 3; pp. 246 - 252
• Main Authors: Tessier, Catherine, Blais, Jean-Simon
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.04.1996; Elsevier
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Binding, Competitive; Biological and medical sciences; Bivalvia - drug effects; Bivalvia - metabolism; Cadmium - metabolism; Cadmium Chloride - metabolism; Cadmium Chloride - toxicity; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Mass Spectrometry; Metallothionein - biosynthesis; Metallothionein - genetics; Metallothionein - metabolism; Mutagens - metabolism; Mutagens - toxicity; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity; Cadmium; Complexation; Subchronic; Ecotoxicology; Toxicity; Dreissena polymorpha; Heavy metal; Dose activity relation; Pollutant; Bivalvia; Invertebrata; Mollusca; Biological accumulation; Metallothionein
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1006/eesa.1996.0031

Metallothioneins have been detected and investigated in zebra mussels (Dreissena polymorpha) using high-performance liquid chromatography (size exclusion) coupled with microatomization–AAS or inductively coupled plasma mass spectrometry. The mussels were exposed to 0.2, 2, and 20 μg/liter Cd2+(as CdCl2) for 1 month under controlled temperature and dietary conditions. Elevated (relative to control) concentrations of tissue Cd2+were detected in all specimens exposed to 2 μg Cd/liter and more than 50% of the specimens exposed to 0.2 μg Cd/liter, demonstrating thatDreissenacannot regulate Cd2+at trace exposure concentrations. In most specimens, at least 85% of the measured Cd2+was bound to metallothioneins. After reduction and exposure to excess Cd2+, the metallothionein fraction of all extracts adsorbed similar quantities of Cd2+, indicating that the physiological concentration of metallothionein in the exposed specimens remained similar to the basal concentration in the control specimens. Thus, a short-term exposure to environmentally relevant concentrations of Cd2+did not produce a genetic induction of metallothionein biosynthesis as generally observed in specimens exposed to higher concentrations of d10metals.