CHANGES IN ANTIOXIDANT ENZYMES ACTIVITIES, AGGREGABILITY AND MALONYLDIALDEHYDE CONCENTRATION IN BLOOD-PLATELETS FROM PATIENTS WITH CORONARYHEART-DISEASE

In 41 patients with coronary heart disease (CHD) the concentrations of total blood platelet malonyldialdehyde (MDA: 2.11 +/- 0.25 nmol/109 p latelets) and MDA corresponding to thromboxane A2 (TXA2 0.84 +/- 0.13 nmol/109 platelets) were increased in comparison with values in blood platelets of healthy subjects (1.19 +/- 0.09 and 0.71 +/- 0.05 nmol/10 (9) platelets), respectively. The increased aggregability with ADP and thrombin of patient platelets was also observed. In relation to the b lood platelets of healthy subjects, the antioxidant enzymes activities of patient blood platelets were significantly (P < 0.001) decreased. Platelet glutathione peroxidase (GSH-Px) activity of the patients (11. 3 +/- 0.85 U/g protein) was significantly lower than controls (18.3 +/ - 1.12 U/g protein). In patients with CHD the activities of the other antioxidative platelet enzymes: catalase (Cat, 7.37 +/- 1.38 U/g prote in) and superoxide dismutase (SOD, 1529.4 +/- 167 U/g protein) were al so significantly decreased in comparison with values for healthy subje cts (Cat: 9.06 +/- 1.30 U/g protein and SOD: 1987 +/- 230 U/g protein, respectively). It is suggested that antioxidative defense in blood pl atelets may affect the haemostatic processes and lipid peroxidation in patients with CHD.