Histograms of infarct size and HO-1 expression in hearts at 4 weeks after LAD ligation. From left to right: sham operated (n = 6), vehicle-treated MI (n = 16), CoPP-treated MI (n = 14) and CoPP + SnMP-treated MI rats (n = 6). A. Representative freshly-cut transverse sections used for determination of infarct size (upper) and quantitative results on infarct size (lower) expressed as mean ± SE percentage of left ventricle. RV: right ventricle; LVP: left ventricular posterior free wall; LVA: left ventricular anterior free wall. B. Representative western blots (upper) and quantitative results from densitometric analysis of HO-1 and β-actin expression (lower) of the corresponding regions shown in the areas outlined by the black boxes and labeled with letters in the representative freshly-cut transverse section: a) right ventricle wall; b) left ventricle posterior wall, opposite to LAD territory; c) border region to LAD area and d) central zone of the infarcted area. Histograms are expressed as ratio between HO-1 and the comparative protein β-actin.