Spectral analysis of exhaled air under airway hyperreactivity development

Abstract

Exhaled air gases were investigated in experimental animals using intraresonator laser acousto-optic sensor ILPA-1 and methane detector before and after sensitization with ovalbumin. Absorption lines typical for CO2 and NH3 were found in exhaled air of intact guinea pigs. After the challenge inhalation, absorption coefficients for СО₂ and NH₃ decreased and absorption lines for N₂O and NO₂ occurred. Methane flow decreased after sensitization. Reduction in CO₂ concentration could be due to lowering gas exchange between the alveolar air and the blood because of breathing disorders. Ammonium having alkaline properties can bind and precipitate bronchial secret due to pH shift to acidic media. N₂O и NO₂ are products of NO metabolism and could occur because of enhanced nitric oxide production by inducible NO-synthase. Methane flow reduction is thought to be due to inhibition of airway microflora.