Figure 1.

Melatonin reduced cardiomyocyte apoptosis and improved cardiac function in diabetic mice but not in SIRT1^−/− diabetic mice. (A) Representative echocardiography images. (B) Left ventricular ejection fraction (LVEF). (C) Left ventricular fractional shortening (LVFS). (D) Left ventricular end‐systolic volume (LVESV). (E) Apoptosis index. (F) Myocardial caspase‐3 activity (fold over Con). (G) Representative photomicrographs of TUNEL‐stained and DAPI‐stained heart sections. Original magnification ×400. (H) Protein expression of SIRT1. Presented values are means ± SEM. DM, diabetes mellitus; Mel, melatonin. n = 8 in each group. **P < .01 vs Con. # P < .05, ## P < .01 vs DM. ^ P < .05, ^^ P < .01 vs DM+Mel