Changes in antioxidant enzymes activities, aggregability and malonyldialdehyde concentration in blood platelets from patients with coronary heart disease.

In 41 patients with coronary heart disease (CHD) the concentrations of total blood platelet malonyldialdehyde (MDA: 2.11 +/- 0.25 nmol/10(9) platelets) and MDA corresponding to thromboxane A2 (TXA2 0.84 +/- 0.13 nmol/10(9) 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 blood 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 protein) and superoxide dismutase (SOD, 1529.4 +/- 167 U/g protein) were also significantly decreased in comparison with values for healthy subjects (Cat: 9.06 +/- 1.30 U/g protein and SOD: 1987 +/- 230 U/g protein, respectively). It is suggested that antioxidative defense in blood platelets may affect the haemostatic processes and lipid peroxidation in patients with CHD.