Acute inhalation of cigarette smoke increases lower respiratory tract nitric oxide concentrations

Abstract

These findings were unexpected in both their direction and time course. They suggest a novel mechanism for the handling of NO in the human lung. We hypothesise that NO is trapped in the epithelial lining fluid (ELF) of the normal human respiratory tract in bioequivalent forms such as S-nitrosothiols or peroxynitrite and that this trapping mechanism is sensitive to the redox state of the ELF. LRT NO concentrations will thus increase with oxidant exposure and decline as pulmonary antioxidant defence mechanisms take effect. These findings may have implications for the pathogenesis and diagnosis of oxidant mediated pulmonary disease.