Oxygen free radicals and the effect of a free radical scavenger in patients with intermittent claudication

Oxygen free radicals (OFRs) are implicated in tissue injury during postisch emic reperfusion and play an important role in the pathogenesis of atherosc lerosis. In patients with intermittent claudication the ischemia-reperfusio n phenomenon could be reproduced after exercise, thus influencing the evolu tion of chronic peripheral arterial occlusive disease (CPAOD). The aim of t his study was to investigate the behavior of OFRs and the effect of a free radical scavenger in patients with stage IIB CPAOD, Malondialdehyde (MDA), a reliable index of OFRs production, was measured in the serum of 19 patien ts with stage IIB CPAOD and 42 healthy controls. The blood samples were col lected from a foot vein in resting condition and during reperfusion after 5 minutes of provoked ischemia. These measurements were repeated after 3 and 12 weeks of oral treatment with the free radical scavenger trimetazidine h ydrochloride (60 mg daily). Statistical analysis of the findings revealed t hat resting MDA was significantly higher in claudicants when compared to th e healthy controls (1.247 +/- 0.25 mu mol/L vs 1.021 +/- 0.278 mu mol/L, p < 0.005). During postischemic reperfusion (PIR) the MDA levels were signifi cantly increased in claudicants (resting vs PIR: 1.247 +/- 0.25 vs 4.60 +/- 0.86 mu mol/L, p < 0.001). The administration of trimetazidine led to a si gnificant: reduction of the PIR MDA levels (before treatment 4.60 +/- 0.86 mu mol/L vs 3 weeks 3.93 +/- 0.63 mu mol/L and vs 12 weeks of treatment 2.9 8 +/- 0.29 mu mol/L, p < 0.001 and p < 0.001, respectively). These findings indicate that claudicants are at increased risk of oxidative damage after exercise. Long-term administration of the free radical scavenger trimetazid ine attenuates reperfusion injury in patients with stage IIB CPAOD.