RESUMO
BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor-α (PPAR-α) activation has been reported to reduce myocardial ischemia-reperfusion (I/R) injury by inhibiting cell apoptosis. However, the antiapoptotic mechanism of PPAR-α is still unknown. Fenofibrate is a PPAR-α agonist In the present study, we investigate the effects and relevant mechanism of fenofibrate on experimental myocardial ischemia-reperfusion (I/R) injury in rats. METHODS: Adult male Wistar rats were pretreated with fenofibrate (80 mg/kg) daily for a period of 7 days. After the treatment period, myocardial I/R injury model was made by left anterior descending coronary artery ligation for 45 min and reperfusion for 120 min. Myocardial infarct size, malondialdehyde (MDA) cleaved-caspase-9 protein expression, PPARα and uncoupling protein 2 (UCP2) mRNA levels in myocardial tissue were detected Cell apoptosis was detected by Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Serum lactate dehydrogenase and creatine kinase activities were measured in rats pretreated with fenofibrate The ultrastructure of myocardial tissues was observed. RESULTS: Significant increases in myocardial cell apoptosis, malondialdehyde (MDA) level and cleaved-caspase-9 protein expression level in myocardial tissue were observed, along with reductions of PPARα and uncoupling protein 2 (UCP2) mRNA levels in myocardial tissue of the experimental myocardial ischemia-reperfusion (I/R) injury in rats. Impaired mitochondria were also observed under electron microscopic. However, pretreatment of ischemia/reperfusion rats with fenofibrate brought the biochemical parameters and related genes expression levels to near normalcy, indicating the protective effect of fenofibrate against myocardial ischemia/reperfusion injury in rats. CONCLUSIONS: The PPAR-α activator fenofibrate conferred cytoprotective effect against myocardial ischemia-reperfusion (I/R) injury in rats. Associated mechanisms involved decreased cleaved-caspase-9 expression and decreased cell apoptosis.
