Fig. 2. Phosphorylation of p38-MAPK and Hsp-27 by CuCl₂. (A,C) Protein (A, 50 µg or C, 100 µg) from Rana ridibunda hearts perfused in the absence (Con) or presence of increasing concentrations of CuCl₂ (50–500 µmol l^–1) for 15 min was analysed by immunoblotting with anti-p38-MAPK (Ai) and anti-Hsp27 (C) phosphospecific antibodies. As a positive control, extracts from hearts perfused with 50 µmol l^–1 H₂O₂ for 2 min were included. Identical samples were assayed with an anti-actin antibody as a control for protein loading (Aii). (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.