Fig. 8. Effect of HOE642, ouabain, catalase, SOD, SP600125 (SP) and AS601245 (AS) on hyperthermia-induced cleavage of PARP (A: upper panel). Proteolytical processing of PARP was detected in extracts (50 µg of protein) from control hearts (0.5 h equilibration followed by 4 h perfusion at 25°C) or hearts perfused after equilibration for 4 h at 42°C in the presence or absence of HOE642 (5 µmol l^–1), ouab (100 µmol l^–1), catalase (150 U ml^–1), SOD (30 U ml^–1), SP (10 µmol l^–1) and AS (1 µmol l^–1). To confirm equal protein loading the membranes were re-probed with an anti-actin antibody (A: bottom panel). Densitometric analysis of the band corresponding to the fragment of PARP was performed by laser scanning (B). Western blots shown are representative of at least three independent experiments while data are means ± s.e.m. for at least three independent experiments. P<0.001 vs control hearts and ^*P<0.001 vs hearts perfused at 42°C.