Plasma nitrite/nitrate and total thiols as markers of nitric oxide production and oxidative stress in patients with chronic obstructive pulmonary disease and chronic respiratory insufficiency

The physiopathology of various inflammatory processes is associated with an increased production of nitric oxide (NO) and a decrease in reduced thiol molecules, e.g. glutathione, by the associated oxidative stress. Chronic obstructive pulmonary disease (COPD) and chronic respiratory insufficiency (CRI) are conditions characterized by the presence of an inflammatory state. Since there is evidence that NO is rapidly converted into nitrite/nitrate, we measured the levels of its metabolites, nitrite and nitrate, and of total thiols, including reduced glutathione, in the plasma of patients with clinical exacerbation of COPD and CRI. Nitrite/nitrate values were significantly higher than those of the controls. In contrast, total thiols were significantly lower. There was a strong negative correlation coefficient between nitrite/nitrate levels and total thiols (r = -0.76). We conclude that nitrite/nitrate and total thiols may be a useful and practical marker for monitoring disease activity in COPD and CRI patients. Med Sci Res 26:375-376 (C) 1998 Lippincott-Raven Publishers.