Role of matrix metalloproteinaseª²9 in the diagnosis of myocardial reperfusion injury

    SHAN Yan, WU Guoª²Hua, ZHANG Qian

    1Department of Clinical Medicine, Nursing College, 2Department of Surgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China

    ¡¾Abstract¡¿ AIM: To study the roles of matrix metalloproteinaseª²9 (MMPª²9) in the myocardial reperfusion injury. METHODS: Forty patients treated by open heart surgery during cardiopulmonary bypass (CPB) were randomly divided into 2 groups: group ¢ñ(cold crystalloid cardioplegia, n=20) and group ¢ò( warm blood cardioplegia, n=20). The blood samples were taken at preoperative 3, 6, 24, 48 and 72 h after aortic unclamping to measure the levels of plasma MMPª²9 and TNFª²¦Á. The cross clamp time, CPB time and the time to extubation were recorded respectively. Myocardial samples were obtained 10 min before aortic clamping and 30 min after aortic unclamping to observe the changes of the myocardial ultrastructure. RESULTS: MMPª²9 and TNFª²¦Á levels were normal before operation but increased remarkably following aortic unclamping. MMPª²9 and TNFª²¦Á levels reached the peak 24 h after operation and decreased progressively to be normal at 72 h in the two groups. The plasma MMPª²9 and TNFª²¦Á levels were significantly lower in group ¢ò than those in group ¢ñ and positive correlations of plasma MMPª²9 concentration to TNFª²¦Á concentration and cross clamp time were observed. CONCLUSION: MMPª²9 is clinically valuable in evaluating the myocardial injury degree, prognosis and myocardial protective effect in open heart surgery during CPB. ......