S1P1R activation reduces the area of I/R-induced ischemic injury in WT but not in ALDH2*2 hearts. (A) Qualitative and (B) quantitative representation of 2,3,5-triphenyltetrazolium chloride (TTC) staining in 2-mm-thick left ventricle slices. WT and ALDH2*2 mouse hearts were subjected to 120 minutes of reperfusion (I/R, WT, n = 5; ALDH2*2, n = 7) with SEW2871 alone (0.1 μM WT, n = 6; ALDH2*2, n = 6) or in the presence of W146 (3 μM; WT, n = 6; ALDH2*2, n = 6). Other hearts were analyzed after IPC (WT, n = 5; ALDH2*2, n = 8). (A) Scale bar = 1 mm. Bars indicate mean ± S.E.M. of independent experiments. Pale areas indicate I/R-injured tissue; healthy tissue is colored in red. *P < 0.05; **P < 0.01; ***P < 0.001, by unpaired t test.