It has been reported that acetaldehyde may be a main factor of alcohol-induced bronchoconstriction in Japanese patients with asthma. The purpose of this study was to investigate the direct action of acetaldehyde on the airway in asthmatic and healthy nonasthmatic subjects. We investigated the bronchial response to inhalation of ascending doses (5, 10, 20, and 40 mg/ml) of acetaldehyde in nine asthmatic subjects, who were treated with placebo or terfenadine for 4 days in a double-blind, randomized, placebo-controlled, crossover fashion, and in nine age- and sex-matched healthy subjects. The bronchial responsiveness to inhaled methacholine was also measured in the same asthmatics on a separate day. Inhaled acetaldehyde caused marked (more than 20%) significant decrease in FEV1 in asthmatics after placebo, which was larger than that in asthmatics after terfenadine and in healthy subjects. There was no significant difference in the decrease in FEV1 between asthmatics treated with terfenadine and healthy subjects. There was a significant correlation between the methacholine and acetaldehyde concentrations producing a 20% fall in FEV1 in asthmatics. We conclude that acetaldehyde causes bronchoconstriction indirectly via histamine release in asthmatics, and that nonspecific bronchial hyperresponsiveness is a necessary precondition for the expression of acetaldehyde-produced bronchoconstriction.
Articles you may be interested inA combined nuclear dynamics and electronic study of the coupling between the internal rotation of the methyl group and the intramolecular proton transfer in 5-methyltropolone Coupling between the internal rotation of the methyl group and proton/deuteron transfer in jet-cooled 5-methyl-9hydroxyphenalenone(OH) and 5-methyl-9-hydroxyphenalenone(OD): Tunneling rate dependence of coupling potentialThe coupling of two large amplitude motions, the internal rotation of the methyl group and the intramolecular proton transfer, has been investigated for jet-cooled 5-methyltropolone, 5-methyltropolone-OD, and the 5-methyltropolone-(H 2 O) 1 1:1 hydrogen-bonded complex by measuring the fluorescence excitation, dispersed fluorescence, and hole-burning spectra in the S 1 -S 0 region. The vibronic bands in the excitation spectrum of 5-methyltropolone consist of four components originating from the transitions between the sublevels in the S 1 and S 0 states. The intensity of the bands, the frequencies, and the change in the stable conformation of the methyl group upon photoexcitation have been analyzed for 5-methyltropolone-(H 2 O) 1 by calculating the one-dimensional periodic potential function, which provides the correlation between the internal rotational levels of 5-methyltropolone-(H 2 O) 1 and the sublevels of 5-methyltropolone. It has been shown that the electronic transitions between the sublevels within the same symmetry are allowed in 5-methyltropolone. The tunneling splitting of the zero-point level in the S 1 state is 2.2 cm Ϫ1 for 5-methyltropolone. The corresponding splitting for 5-methyltropolone-OD is less than 0.5 cm Ϫ1 . A drastic decrease of the tunneling splitting for 5-methyltropolone as compared to that for tropolone ͑19.9 cm Ϫ1 ͒ is ascribed to a strong coupling between the two large amplitude motions in the S 1 state. The existence of a similar coupling has been suggested in the S 0 state of 5-methyltropolone. The excitation of the sublevel in the S 1 state considerably promotes proton tunneling. This effect has been explained by the delocalization of the wave function of the internal rotation of the methyl group. The two-dimensional potential energy surface along the proton transfer coordinate and the rotational angle of the methyl group has been calculated to explain the effects of the coupling on proton tunneling.
A combined nuclear dynamics and electronic study of the coupling between the internal rotation of the methyl group and the intramolecular proton transfer in 5-methyltropoloneCoupling between the internal rotation of the methyl group and proton/deuteron transfer in jet-cooled 5-methyl-9hydroxyphenalenone(OH) and 5-methyl-9-hydroxyphenalenone(OD): Tunneling rate dependence of coupling potential Tunneling in jet-cooled 5-methyltropolone and 5-methyltropolone-OD. Coupling between internal rotation of methyl group and proton transfer
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