Airway inflammation induced by xanthine/xanthine oxidase in guinea pigs.

Airway inflammation is suggested to play an important role in bronchial asthma. However, there is poor documentation about the effects of reactive oxygens on airway tissues in aspect of airway inflammation. Presently, we investigated whether aerosolized xanthine (X)/xanthine oxidase (XOD) induces airway inflammation in anesthetized guinea pigs. Inhalation of X for 5 min followed by inhalation of XOD for 5 min was performed with an ultrasonic nebulizer in anesthetized animals. Airway inflammation was assessed by airway vascular permeability using Pontamine sky blue. Inhalation of X/XOD produced a marked Pontamine sky blue exudation in the trachea, main bronchus and lungs. The X/XOD-induced increase in Pontamine sky-blue exudation was attenuated by pretreatment with inhaled catalase, but not by superoxide dismutase. Additionally, in the bronchus and lungs, the increase in Pontamine sky-blue exudation was significantly suppressed by deferoxamine. The above results indicate that hydrogen peroxide and hydroxyl radical converted from superoxide anion cause an intense airway inflammation.