Fig. 2.

Nrf2 KO mice lose preconditioning induced cardiac protection. Wild type (WT) and Nrf2 KO mice at 8–10 weeks old were used for LAD coronary artery occlusion surgery. For preconditioning, mouse hearts were subjected to 5 min occlusion and 5 min release of the LAD coronary artery for 2 cycles (2× 5′I/5′R). For control group not having 2× 5′I/5′R or preconditioning group with 2× 5′I/5′R, the coronary artery was permanently occluded. At 24 h after permanent occlusion, the hearts and blood were collected for TTC staining to measure areas of infarction (A, B) and for cTnI concentration assay (C) respectively. A series of transverse sections of representative hearts downstream of the ligature are shown (A). Total myocardial areas or areas of infarct were quantified by using NIH Image J software. Each open circle represents the measurement from one animal and average means with standard deviations from 6 to 8 animals are shown with filled-in circles (B). ANOVA was used to determine the significant difference (p < 0.05) between the means. The means labeled “a” are significantly different from that labeled “b” or “c”, whereas the label “b” indicates significant difference from the mean labeled “c”.