Stress protein response and catalase activity in freshwater planarian Dugesia (Girardia) schubarti exposed to copper.

The hsp60 expression pattern and catalase activity in the freshwater planarian Dugesia schubarti exposed to copper under laboratory conditions were investigated. In the hsp60 induction experiments, planarians were exposed to a range of copper concentrations (0-960 microgCu/L) for 4 or 24h, to concentrations of 50 or 100 microgCu/L for 2, 4, 8, and 24h at 19 degrees C, and to heat shock at 27 degrees C for 24h. The concentrations of hsp60 in whole-body homogenates were determined immunochemically by Western blotting. Stress protein induction was detected only after 24h treatment at 27 degrees C. The tissue concentration of hsp60 remained unaltered in Cu-exposed planarians under the experimental conditions used. Catalase activity was significantly induced at concentrations of 40, 80, and 160 microgCu/L after 24h exposure. Our results suggest that catalase levels in planarians could represent biomarkers of interest for the estimation of copper effects in freshwater ecosystems.