ABSTRACT
The potential use of metallothioneins (MTs) as biomarkers of trace metal contamination was evaluated for the first time in the Algerian mouse (Mus spretus). Mice were collected seasonally in an abandoned mining area (Aljustrel) and in a reference area, both located in southern Portugal. MT levels were quantified in liver and kidney by differential pulse polarography and hepatic elemental concentrations (Mn, Fe, Cu, Zn, Se) were determined by particle-induced X-ray emission. Hepatic iron and selenium concentrations were elevated in mice from Aljustrel mine when compared to reference animals. MTs levels were averagely higher in mice from Aljustrel than those originated from the reference area. A season-dependent significant effect was found on the hepatic and renal MT concentrations, characterized by higher levels in winter and lower in autumn. In contaminated mice positive relationship between liver elemental contents (Cu in autumn and Fe in winter) and MTs were found. The seasonal variation of MT suggests that probably physiological and environmental factors could influence hepatic and renal MT induction. Results seem to imply that some environmental disturbance occur in the vicinity of the Aljustrel mine. Therefore, for the management purposes MT levels should be followed in liver of M. spretus, especially in winter. Furthermore, other physiological factors that could influence MT expression and turnover in Algerian mouse should also be monitored.
Subject(s)
Ecosystem , Environmental Monitoring/methods , Metallothionein/analysis , Metals, Heavy/analysis , Mice , Soil Pollutants/analysis , Animals , Biomarkers/analysis , Body Weight/drug effects , Kidney/metabolism , Liver/metabolism , Metals, Heavy/toxicity , Mice/metabolism , Mice/physiology , Mining , Organ Size/drug effects , Portugal , Seasons , Soil Pollutants/toxicityABSTRACT
Heavy metals accumulation in parallel with the evaluation of physiological and biochemical effects resulting from continued metal exposure were considered here using for the first time the great white-toothed shrew Crocidura russula as an in vivo model. Shrews were originated from an abandoned lead/zinc mining area and from a reference area, both in Alentejo, southern Portugal. Hepatic contents of nickel, copper, zinc, cadmium, mercury and lead were quantified by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Haematological parameters (white blood cells, red blood cells, haemoglobin and haematocrit) were obtained in a Coulter Counter Analyser and biochemical markers of the redox balance (glutathione S-transferase, glutathione peroxidase, and glutathione reductase) activities were measured spectrophotometrically using a Duo-50 spectrophotometer. Compared with control animals, significantly higher concentration of hepatic cadmium (9.29 vs. 1.18 micorg/g dry weight) and nickel (1.56 vs. 0.343 microg/g dry weight) were detected in the shrews collected in the mining area. However, no significant changes were observed on haematological or enzymatic parameters in animals exposed to metal pollution. The obtained results show that shrews are good bioaccumulators of toxic heavy metals, but very tolerant to their effects, revealing an interesting long-term adaptation to polluted environments. In addition, this study provides reference values for haematological parameters and antioxidant enzymes levels in C. russula, which may be relevant for comparative purposes in further studies.
