Myocardial infarction in rats causes partial impairment in insulin response associated with reduced fatty acid oxidation and mitochondrial gene expression

Objective Myocardial infarction leads to contractile dysfunction. In patients with diabetes, impaired contractility has been associated with the loss of insulin effects and mitochondrial dysfunction. We assessed cardiac insulin sensitivity and mitochondrial and contractile function in rats after ligation of the left coronary artery. Methods At 2 weeks after left coronary artery ligation, we performed echocardiography in vivo and assessed the substrate use and insulin response in the isolated working heart and the regulation of insulin (Akt, glucose transporter type 4) and mitochondrial signaling (p38 mitogen-activated protein kinase, peroxisome proliferator-activated receptor-γ coactivator 1α, mitochondrial transcription factor A) using polymerase chain reaction and Western blotting. Results The infarcted hearts were dilated and had a reduced ejection fraction (ejection fraction