Increased nitric oxide metabolites in exhaled breath condensate after exposure to tobacco smoke
2001; BMJ; Volume: 56; Issue: 6 Linguagem: Inglês
10.1136/thorax.56.6.456
ISSN1468-3296
Autores Tópico(s)Chronic Obstructive Pulmonary Disease (COPD) Research
ResumoBackground-Cigarette smoking reduces the level of exhaled nitric oxide (NO) in healthy subjects, although the mechanism is unclear.NO is a highly reactive molecule which can be oxidised or complexed with other biomolecules, depending on the microenvironment.The stable oxidation end products of NO metabolism are nitrite and nitrate.This study investigated the eVect of smoking on NO metabolites in exhaled breath condensate.Methods-Fifteen healthy current smokers were recruited together with 14 healthy non-smokers.Measurement of exhaled NO, lung function, and collection of exhaled breath condensate were performed.Nitrite, nitrite + nitrate, S-nitrosothiols, and nitrotyrosine levels were measured.The eVect of inhaling two cigarettes in smokers was also evaluated.The mean level of exhaled NO in smokers was significantly lower than in nonsmokers (4.3 (0.3) ppb v 5.5 (0.5) ppb, p<0. 05).Results-There was no diVerence in the levels of nitrite, nitrite + nitrate, S-nitrosothiols, and nitrotyrosine in the exhaled breath condensate at the baseline visit between smokers and non-smokers.After smoking, nitrite + nitrate levels were significantly but transiently increased (from 20.2 (2.8) µM to 29.8 (3.4) µM, p<0.05).There was no significant change in the levels of exhaled NO, nitrite, S-nitrosothiols, or nitrotyrosine 30 and 90 minutes after smoking.Conclusions-These findings suggest that acute smoking can increase the level of nitrate, but not nitrite, S-nitrosothiols, or nitrotyrosine in breath condensate.The deleterious eVect of oxidant radicals induced by smoking may contribute to the epithelial damage of airways seen in smokers.
Referência(s)