Lipid peroxidation and antioxidant status following thrombolytic therapy for acute myocardial infarction.

We have investigated the timescale of increased lipid peroxidation following successful early thrombolytic therapy for acute myocardial infarction and report for the first time reciprocal changes in plasma chain-breaking antioxidants. Sixty-seven patients were recruited following a first acute myocardial infarction within 6 h of the onset of symptoms and received 70 or 100 mg of recombinant tissue plasminogen activator (Actilyse) as two intravenous bolus injections 30 min apart. Serial blood samples were taken before administration of thrombolytic therapy and after 30 min, 60 min, 90 min, 6 h and 24 h. Coronary artery patency was assessed at 90 min by coronary angiography. Malondialdehyde (MDA), a marker of lipid peroxidation, and the chain-breaking antioxidants alpha-tocopherol, retinol and ascorbate were measured by high performance liquid chromatography. When the coronary artery was patent there was an early rise in plasma MDA (time 0 0.91 +/- 0.05 mumol.l-1) with levels peaking at 90 min (1.02 +/- 0.06, P < 0.05) and returning to baseline by 6 h (0.85 +/- 0.06), accompanied by reciprocal decreases in alpha-tocopherol (time 0 7.13 +/- 0.34 mumol.mmol-1 cholesterol, 90 min 6.64 +/- 0.33, P < 0.05) and retinol (time 0 1.99 +/- 0.10 mumol.l-1, 90 min 1.81 +/- 0.08, P < 0.05). Ascorbate levels did not change significantly until 24 h (time 0 29.5 +/- 4.9 mumol.l-1, 24 h 22.6 +/- 4.4, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)