Objective To study the regulatory effects of Ca 2+ , ATP, ADP and AMP on myocardial nuclear Ca 2+ ATPase activity after ischemia reperfusion injury Methods The model of myocardial ischemia reperfusion injury was established in rats Myocardial nuclei were purified using sucrose density gradient centrifugation The activity of Ca 2+ ATPase was measured with ascertaining phosphate Results Compared with the control, plasma levels of MDA and FFA after myocardial ischemia reperfusion injury increased significantly ( P