Fig. 5. Phosphorylation of p38-MAPK and Hsp27 by the combined effects of CuCl₂ and hyperthermia (42°C). (A,C) Phosphorylated p38-MAPK (A,top) and Hsp27 (C) levels were detected in extracts (50 and 100 µg of protein, respectively) from Rana ridibunda hearts perfused for 15 min with normal bicarbonate-buffered saline maintained at 25°C (Con) or at 42°C, either in the absence or presence of 500 µmol l^–1 CuCl₂. As a positive control, extracts from hearts perfused with 50 µmol l^–1 H₂O₂ for 2 min were included. Identical samples were analysed using an actin antibody as a control for protein loading (A,bottom). (B,D) Densitometric analysis of phospho-p38-MAPK (B) and phospho-Hsp27 (D) bands by laser scanning. Results are means ± s.e.m. for three independent experiments. ^*P<0.05, ^**P<0.01, P<0.001 vs control value.