A Novel Clinical and Laboratory Based Approach to Coronary Heart Disease: Relationship Between Angiography Findings, Antioxidant Enzymes and NO

Authors: BÜLENT SÖZMEN, FEVZİYE UYSAL, DERVİŞ GAZİTEPE, LEYLA ASLAN, ESER YILDIRIM SÖZMEN

Abstract: Atherosclerosis is the most common manifestation of cardiovascular disease. However the exact mechanisms that take place in its pathogenesis have not yet been completely understood. Free radicals and lipid peroxidation may play an important role in the pathogenesis of atherosclerosis and endothelial dysfunction also may be an aggravating factor in this process. Unfortunately all of the previous studies have focused on the atherosclerotic tissue. Our aim was to establish a relationship between the antioxidant enzymes and plasma nitrate as an index of whole-body, endogenous nitric oxide production in coronary heart disease and also the relationship between these parameters and the severity of coronary disease. Thirty-three male patients referred to the Department of Cardiology for coronary angiography were considered for this study. Fifteen healthy men matched with patients for approximate age were selected as a control group. Plasma nitrite, nitrate levels, erythrocyte superoxide dismutase (SOD) and catalase activity were determined and serum lipid analysis was performed. Mean SOD and catalase activity in the patient group were significantly lower than in the controls (P<0.05, P<0.01, respectively). No significant difference was observed in nitrite or total nitrate levels. However nitrate values in patients were lower than in the controls (P<0.05). Although patients who were 55 or younger (n=14), had lower SOD and catalase activity than the control group (P<0.01, P<0.01), there was no significant difference between the nitrite, nitrate and total nitrate levels of these cases and the controls. In older patients (n=19), there was no significant difference in SOD, catalase, nitrite or total nitrate values when compared with the controls. In conclusion, hypercholesterolemia, increased oxygen free radicals, decreased antioxidant enzymes, increased ox-LDL and endothelial dysfunction caused by NO depletion are all intriguing mechanisms which act coherently in the progress of atherosclerosis. We proposed that the factors in the mechanism of atherosclerosis in younger patients is different from that in older ones. The insufficient antioxidant enzyme activity is a triggering factor to atherosclerosis. However it is not yet known if this decrease in antioxidant enzymes is a genetically determined primary factor or a secondary factor due to increased production of free radicals.

Keywords: NO, antioxidant enzymes, coromary heart disease.

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