Experimental studies have shown that the expression levels of angiotensin-converting enzyme, angiotensin (Ang) II, Ang II type 1 receptor, and Ang II type 2 receptor were significantly increased within a few hours in the myocardial ischemic area with reperfusion, indicating that activation of the cardiac local renin-angiotensin system may be important in the regulation of myocardial ischemia/reperfusion injury (35, 37). This evidence concerns the gene REN and myocardial ischemia.