[Cathepsin L expression in plasma after acute myocardial ischemia and ischemia-reperfusion in rats]

To test cathepsin L as a biomarker of myocardial ischemia by examination of cathepsin L expression in plasma after myocardial ischemia and ischemia-reperfusion in rats.The rat models were established and divided in acute myocardial ischemia model (myocardial ischemia 30 min, 1 h, 2 h groups), ischemia-reperfusion model (ischemia-reperfusion group), and isoflurane-pretreated ischemia-reperfusion model (isoflurane-pretreated group), respectively. Normal control group and sham-operated group were established as contrast. The contents of cathepsin L in plasma were examined by ELISA and myocardial infarction areas were measured after TTC staining.No statistical significant changes were found among the experimental groups compared with the normal control group and sham-operated group (P0.05). The cathepsin L from the ischemia-reperfusion group increased to 2.37 times compared with the normal control group (P0.05). The cathepsin L and myocardium infarction size of isoflurane-pretreated group decreased compared with the ischemia-reperfusion group (P0.05).The cathepsin L in plasma is not a promising biomarker of acute myocardial ischemia. Isoflurane preconditioning can reduce the cathepsin L in plasma caused by ischemia-reperfusion injury.