(A). Activation of wild type, heterozygotes and homozygotes mutants of ALDH2 by Alda-1 (100 μM). Enzymatic activity of recombinant ALDH2 proteins (20μg each) are presented as percent of control [n=3, **p<0.01 vs. control; (5)]. Alda-1 reduces cardiac damage in an ex vivo model of ischemia and reperfusion injury (B). Top: Ex vivo cardiac ischemia model protocol. Myocardial infarct size, induced by 35 minutes ischemia followed by 60 minutes of reperfusion after 10 minutes pretreatment with Alda-1 (20 μM) or vehicle control using Langendorff apparatus, as in Fig. 1B, 2B [n=7, *p<0.01; (5)]. Representative cross-sectional slices derived from a single heart stained by TTC without (control) and with Alda-1 treatment (n=7). Infarct area is indicated by the light pink color and marked with dotted lines. Alda-1 reduces cardiac damage in an in vivo model of acute myocardial infarction (C). Top: In vivo cardiac ischemia model protocol. Reduction of infarct size by pretreatment of Alda-1 (8.5mg/kg) before LAD ligation was also determined in vivo (n=7, **p<0.01; SOM, Fig. S6A, B). Shown is TTC staining of representative cross-sectional slices (seven rats per group).