The results of TTC staining showed that the myocardial infarction area in model group was (34.51 ± 3.63)%, however, in inactivated Lac groups it was (22.17 ± 3.19)% (P<0.05) and (14.37 ± 1.98)% (P<0.01) at low concentration and medium concentration, respectively (Figure 1B), which indicated the obvious reduction in infarct area. This evidence concerns the gene LCT and myocardial infarction.