The enzymes involved in the oxidative metabolism of pyruvate in mitochondria – such as isocitrate dehydrogenase (ICDH), alpha-ketoglutarate dehydrogenase (α-KGDH), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH) – showed reduced activity in rats with myocardial infarction (MI) compared to the control group. Here, MDH2 is linked to myocardial infarction.