Effects of ozone on influenza virus-induced airway hyperreactivity in rats / 천식및알레르기

ABSTRACT

BACKGROUND: Ozone is one of the most ubiquitous oxidant in urban air and may exacerbate respiratory diseases such as asthma. OBJECTIVE: We examined whether ozone can influence airway hyperresponsiveness induced by influenza virus-infection. SUBJECT AND METHOD: Rats were exposed to ozone, acutely to 1.0ppm and 0.25ppm for 23.5hrs. At 2hrs post cessation of ozone exposure, animals were infected with rat-adapted influenza virus intra-nasally. On day 3 post-virus inoculation, pulmonary mechanics were measured during an intravenous challenge with acetylcholine . Cumulative doseresponse functions were obtained by doubling the rate of the intravenous infusion every 2min. RESULTS: ACh increased airway resistance in a dose-dependent manner. Neither of the concentrations of ozone altered the airway responses to ACh. Animals infected with virus developed hyperresponsiveness to ACh as was expected. Pre-exposure to 1.0ppm ozone for 23.5hrs aug- mented the virus-induced airway hyperresponsiveness, while 0.25ppm did not. CONCLUSION: Acute exposure to ozone can synergistically act on virus-induced airway hyperreactivity.