(A) Area at risk ratio (%) in the experimental groups of hearts submitted to regional ischemia-reperfusion. (B) Infarct to risk ratio (%) in hearts submitted to regional ischemia-reperfusion after L2 or BNP perfusion alone or after pretreatment with the natriuretic peptide receptor antagonist isatin or the selective mitoKATP channel blocker 5-hydroxydecanote (5-HD). (C) Infarct to risk ratio (%) in hearts submitted to global ischemia-reperfusion after L2 or BNP perfusion. Myocardial infarction was induced by 30 min ischemia followed by 90 min reperfusion. Data are mean ± SEM. For number of animals see Table 2 and Table 3. *, p<0.05, **, p<0.01, ***, p<0.001 versus vehicle, ††, p<0.01 versus corresponding group not treated with antagonist.