Background: Reactive oxygen species (ROS) have been proposed to play importantpathogenic roles, especially in harmful oxidative modifications of low-density cholesterol. Redox balancewithin the organism is largely determined by the activities of anti-oxidative enzymes of red blood cellsand by the total anti-oxidative capacity of the serum (TAS). Material/Methods: SOD and GPx activitiesand TAS in 13 men aged 42-65 years with coronary atherosclerosis (group I) were compared with those ofboth 15 clinically healthy pilots matched for age and lipid abnormalities (cholesterol and triglycerides)(group II) and 14 age-matched pilots without lipid abnormalities (group III). Results: There were statisticallysignificant differences in SOD and GPx activities and in TAS between the groups. Conclusions: 1. SODand GPx activities and TAS were lower in men with advanced coronary atherosclerosis that in age-matchedclinically healthy men with similar dyslipidemia and were even further decreased compared with clinicallyhealthy men without dyslipidemia. 2. The decrease in SOD and GPx activities and TAS in men with advancedcoronary atherosclerosis was more pronounced than the degree of hypercholesterolemia or hypertriglyceridemia.3. If hyperlipidemia and the activity of antioxidative enzymes and TAS were considered without referenceto other risk factors of atherosclerosis, it appeared that the decreases in SOD, GPx, and TAS may playa more important role in the development of the atherosclerotic process than isolated increases in freecholesterol or triglyceride levels.

Keywords: Aerospace Medicine, Antioxidants - metabolism, Case-Control Studies, Cholesterol - blood, Coronary Artery Disease - enzymology, Erythrocytes - enzymology, Glutathione Peroxidase - blood, Reactive Oxygen Species - blood, Superoxide Dismutase - blood, Triglycerides - blood