CARDIOPROTECTION OF FIBRATES IN RAT MODEL OF MYOCARDIAL ISCHEMIA: REPERFUSION

The present study was designed to investigate the effect of Clofibrate, an agonist of peroxisome proliferator activated receptor-α (PPAR-α), on ischemia-reperfusion (I/R)-induced myocardial injury. The isolated Langendorff-perfused rat hearts were subjected to global ischemia for 30 min followed by reperfusion for 120 min. Myocardial infarct size was assessed by volume methods using triphenyltetrazolium chloride staining. Coronary effluent was analyzed for the release of lactate dehydrogenase (LDH) and creatine kinase (CK) to assess the degree of cardiac injury. Moreover, oxidative stress in the heart was assessed by measuring lipid peroxidation, superoxide anion generation and reduced glutathione. I/R was noted to produce myocardial injury, as assessed in terms of increase in myocardial infarct size, LDH and CK in coronary effluent. Moreover, oxidative stress was noted to be increased due to I/R injury as assessed in terms of decreased TBARS (thiobarbituric acid-reactive substance) and superoxide anion generation levels alongwith increase in reduced glutathione levels in the heart. Treatment with Clofibrate showed cardioprotection against I/R-induced myocardial injury in rat hearts as assessed in terms of reductions in myocardial infarct size, LDH and CK levels in coronary effluent. Moreover, I/R-induced oxidative stress was noted to be reduced by Clofibrate treatment. It may be concluded that the observed cardioprotective potential of Clofibrate against I/R-induced myocardial injury was due to the reductions in infarct size and oxidative stress .