Effect of intravenous Nitroglycerin on lipid peroxidation after thrombolytic therapy for acute myocardial infarction

Free oxygen radicals are produced after coronary artery occlusion and reper fusion. Polyunsaturated fatty acids are oxidized by free radicals to lipid peroxides. Measurements of plasma malondialdehyde (MDA) formed by the break down of lipid peroxides are often used as markers of lipid peroxidation. Th e effect of intravenous nitroglycerin on plasma MDA levels was studied in 4 3 patients who received thrombolytic therapy for acute myocardial infarctio n. Plasma MDA levels in patients were elevated on admission to the hospital compared with healthy controls, and normalized within 48 hours. A greater increase in plasma MDA concentrations after thrombolysis was found in patie nts with noninvasive signs of reperfusion than in patients judged to have a persistent occlusion. In the 23 patients receiving immediate intravenous n itroglycerin infusion, plasma MDA levels did not change from baseline to 90 minutes (0.92 +/- 0.22 and 0.92 +/- 0.23 mu mol/L, p = 0.99), whereas a si gnificant increase was found in the 20 control patients who did not receive nitroglycerin (from 0.83 +/- 0.22 to 1.01 +/- 0.30 mu mol/L, p = 0.0004) ( p = 0.036 for the difference between groups). Successful reperfusion after thrombolytic therapy entails increased lipid peroxidation. Intravenous nitr oglycerin reduces lipid peroxidation during myocardial ischemia and reperfu sion. (C) 1998 by Excerpta Medica, Inc.