[Changes in blood levels of nitric oxide, oxidation and lipoperoxidation in patients with silicosis]

To explore the relationship between nitric oxide, oxidation, lipoperoxidation and silicosis.

Blood plasma levels of nitric oxide (P-NO), vitamin C (P-VC), vitamin E (P-VE), beta-carotene (P-beta-CAR), lipoperoxidase (P-LPO), and erythrocyte activities of superoxide dismutase (E-SOD), catalase (E-CAT), glutathione peroxidase (E-GSH-Px) and lipoperoxidase (E-LPO) were measured in 73 patients with silicosis and 60 healthy subjects.

The average levels of P-VC, P-VE, P-beta-CAR, E-SOD, E-CAT and E-GSH-Px were significantly lower and the average levels of P-NO, P-LPO and E-LPO significantly increased in the silicosis with varied severity of the disease and lung function status more than in the controls. There was linear relationship between all the above indices and length of the disease. Stepwise regression analysis showed that the severity of the disease and lung function status correlated most closely with the levels of P-NO, P-VE, E-SOD and E-LPO.

Metabolism of nitric oxide was abnormal, balance between oxidation and antioxidation was disturbed seriously, and oxidation and lipoperoxidation reaction pathologically exacerbated in the bodies of the patient with silicosis.