PULMONARY CLEARANCE AND LUNG-FUNCTION - INFLUENCE OF ACUTE TOBACCO INTOXICATION AND OF VITAMIN-E

Cigarette smoking increases the alveolar epithelial permeability to sm all solutes, as assessed by the pulmonary clearance of aerosolized Tc- 99m-labeled diethylenetriaminepentaacetate. The involvement of lipid p eroxidation in this increased clearance was tested in eight asymptomat ic young smokers by investigating the effects of a 3-wk supplementatio n with oral vitamin E (1,000 IU/day) on pulmonary clearance according to a protocol designed as a single-blind crossover study. Indexes of a cute tobacco intoxication (exhaled CO, carboxyhemoglobin, and urinary cotinine) and lung function parameters [including Krogh factor (K-CO)] were also studied. Under control conditions, pulmonary clearance was abnormally increased (2.93 +/- 0.78%/min), whereas K-CO was in the nor mal range. Pulmonary clearance correlated strongly with expired CO (P < 0.04), HbCO (P < 0.005), urinary cotinine (P < 0.003), and K-CO (P < 0.004). Supplementation with vitamin E, a highly efficient antioxidan t, neither decreased the pulmonary clearance nor altered the above cor relations. However, the strong correlations observed between pulmonary clearance and indexes of acute tobacco intoxication, which reflect th e amount of inhaled smoke and the resultant oxidant stress, do not all ow exclusion of the involvement of lipid peroxidation in the pulmonary clearance increase observed in smokers.