Fig. 2

The cardiac ultrastructure was measured by TEM. a Representative images of the hearts obtained from TEM are shown. Scale bars: 2 µm and 500 nm. Arrows indicate mitochondria with vacuolization. b Mitochondrial area, c aspect ratio, d degree of branching and e number of mitochondria with vacuolization were analysed. Values are presented as the means ± SDs. *P < 0.05, **P < 0.01, ***P < 0.001 vs CON group by one-way ANOVA; ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 vs DM group by one-way ANOVA