The observation on the change of extracellular superoxide dismutase of acute coronary syndromes

XIE Xiao-bo; SU Jian-xin; LIU Jian-wei; PAN Qiao

Abstract：Objective:Toobservateplasmaexpressionlevelsofextracellularsuperoxidedismutase(ecSOD),amajoran-tioxidant enzyme in the cardiovascular system,in patients with acute coronary syndromes. Methods:Twenty consecutive patients with acute myocardial infarction( AMI),17 patients with unstable angina( UA),13 patients with stable angina,and 20 control subjects were studied. The levels of plasma ecSOD expression were assessed by the difference in plasma ecSOD concentrations before and after intravenous heparan injection. Results:In the patients with AMI,plasma ecSOD expression was significantly higher on day 1 after the onset of AMI(150 ± 8)ng/mL as compared with the control subjects(115 ± 4)ng/mL(P﹤0. 05). The plasma ecSOD expression returned to the normal range on day 7(104 ± 8)ng/mL,and that level persisted thereafter. The plasma ecSOD expression was also significantly higher in the patients with unstable angina( 158 ± 10 )ng/mL than in those with stable angina(124 ± 8)ng/mL or in the controls(115 ± 4)ng/mL(P﹤0. 05 each). Moreover,in the patients with AMI,higher levels of plasma ecSOD expression on day 1 were significantly associated with smaller myocardial infarct size( P﹤0. 05). Conclusion:This is the first clinical demonstration showing that plasma ecSOD may be upregulated in acute coronary syndromes in humans in vivo. ecSOD may play an important protective role against increased oxidative stress during acute is-chemic coronary events.