Oxidative stress in patients with primary pulmonary hypertension.

We studied the role of oxidative stress in the pathogenesis of primary pulmonary hypertension. In patients with primary pulmonary hypertension the content of malonic dialdehyde in the plasma was higher than in healthy volunteers (5.18 0.46 and 2.95 0.14 nmol/liter, respectively, p<0.01). However, glutathione peroxidase activity in the plasma decreased in these patients (0.50 0.17 vs. 1.19 0.14 U/ml in the control, p<0.05). By contrast, glutathione peroxidase activity in erythrocytes from patients surpassed the control (6.13 0.39 and 4.63 0.45 U/h hemoglobin). The increase in malonic dialdehyde content in the plasma and glutathione peroxidase activity in erythrocytes and the decrease in glutathione peroxidase activity in the plasma were most pronounced in patients with severe cardiac insufficiency and pulmonary hypertension. Our results indicate that antioxidant preparations improve the prognosis in patients with primary pulmonary hypertension.