فعالیت آنزیمهای آنتی‌اکسیداتیو کاتالاز و گلوتاتیون ردوکتاز گلبولهای قرمز خون در بیماران مبتلا به گرفتگی عروق کرونر

ABSTRACT Free radicals and lipid peroxidation have been proposed to play a role in the pathogenesis of atherosclerosis. Reactive Oxygen species can induce the oxidation of low-density lipoproteins and LDL oxidation has been shown to be responsible for plaque formation in the vessel wall. However living cells and organisms are very well equipped with defense systems against the damaging effects of radical oxygen species. Free radical scavenging enzymes are an important part of this system. The aims of this study were to evaluate the enzymatic activity of antioxidative enzymes of erythrocytes, catalase(CAT) and glutathione reductase(GR), that might be indicators of protective mechanisms involved in atherosclerosis, and also to evaluate the serum lipids and lipoproteins that thought to be correlated with these two antioxidative enzymes. The study comprised 90 patients with angiographically proved coronary stenosis in Tehran Rajai cardiovascular center and 30 subjects without and coronary heart disease used as controls. Glutathione reductase activity in erythrocytes was evaluated by a method of Goldberg & Spooner spectrophotometrically. Catalase activity in erythrocytes was assayed by the method described by Hugo Aebi with using a UV/visbile spectrophotometer. Serum lipids were measured by automated methods. Patients had similar glutathione reductase activities compared to the control subjects. However the catalase activity was decreased in erythrocytes of the atherosclerotic patients compared to the control subjects (P<0.05) and those with three vessels stenosis (P<0.008). In patients with atherosclerosis, the serum cholesterol, LDL-c and LDL-c/HDL-c (atherogenic index) were significantly increased compared to the control group (P<0.002). Atheroscleroticsmoker patients had similar catalase activity compared to the nonsmoker patients. However the glutathione reductase activity was decreased in erythrocytes of the atherosclertic smoker patients compared to the nonsmoker patients(P<0.003). No significant correlations were found between serum lipids and two antioxidative enzymes activity in patients and control subjects. However the activity of catalase was positively correlated to atherogenic index(r=o.49, P<0.005) within control group.