Fig. 7. Phosphorylation of HSP27 by H₂O₂. Protein (100 µg) from hearts perfused with 30 µmol l^-1 H₂O₂ for 2 min in the absence or presence of 25 µmol l^-1 PD98059 or 1 µmol l^-1 SB203580 was assessed by immunoblot for phosphospecific anti-HSP27 antibody (A, top panel) or total anti-HSP antibody (A, bottom panel). As a positive control, extract from hearts perfused with 0.5 mol l^-1 sorbitol was included. Blots are representative of three independent experiments. (B) Densitometric analysis of phospho-HSP27 bands by laser scanning. Results are means ± S.E.M. for three independent experiments. P<0.001 vs control value. C, control; S, sorbitol.