The Expression Of Uncoupling Protein 2 In Acute Myocardial Ischemic-reperfusion Injury Of Rat Heart

Objectives: Acute myocardial Ischemic - reperfusion injury of heart causes increasing production of reactive oxygen species (ROS) and results in a serial of damages such as: lipid peroxidation, DNA injury and apoptosis etc. Recently, it has been reported that Uncoupling Protein 2(UCP₂) is widespread in mitochondrial inner membrane of tissue including cadiocyte, and can decrease the production of ROS. The present experiment is to investigate the expression of UCP₂ in acute myocardial ischemic-reperfusion injured rat heart. Methods: 24 SD rats were divided into three groups at random, 8 animals of each group: sham-operation group of (Sham group), 2 hour post-ischemic- reperfusion injury group (2h group); and 6 hour post-ischemic- reperfusion injury group (6h group). The left anterior descending coronary artery (LAD) was occluded 2mm from its origin with a 7-0 silk knot for 30 min, and then the knot was released, initiating reperfusion. Coronary occlusion was confirmed by ST elevation on ECG. At the end of the 2 or 6 hours of reperfusion period, the hearts were removed for UCP₂ analysis. The expression of UCP₂ was measured by Western Blotting and Immunohistochemistry. Results: (1) ST-T change on ECG was seen in rats occluded the left anterior descending coronary artery (LAD). (2) The immunohistochemistry showed that the brown positive granules were not expressed in Sham group, however, the...