ABSTRACT
In this study, the changes in the combined plasma concentrations of nitrate and nitrite as an index of nitric oxide [NO] concentration as well as the changes in the concentrations of major serum antioxidants [ascorbic acids and methionine] in smokers after smoking a single cigarette were measured. The effect of smoking a single cigarette was studied in 30 smokers and 15 nonsmokers [controls]. Plasma were collected before 5 and 60 minutes after smoking a single cigarette to measure the plasma levels of NO metabolites and antioxidants. Smoking a single cigarette significantly decreased NO metabolites concentrations by 10.2 +/- 1.1 mumol/L compared with the plasma concentrations at pre-smoking [13.5 +/- 1.2 mumol/L. The concentrations of ascorbic acid and methionine were also significantly lower after smoking a single cigarette [39.7 +/- 3.3 mumol/L and 8.1 +/- 0.7 mumol/L, respectively] compared with the plasma concentrations at pre-smoking [51.8 +/- 4.2 mumol/L and 10.2 +/- 0.7 mumol/L, respectively, for both]. These parameters returned to the pre-experimental levels at 60 minutes after smoking cessation. In nonsmokers, the same results were obtained, except that the impairments of NO and antioxidant release from the endothelium are less than in nonsmokers