A GUINEA-PIG MODEL OF ULTRASONICALLY NEBULIZED DISTILLED WATER-INDUCED BRONCHOCONSTRICTION

Ultrasonically nebulized distilled water-induced bronchoconstriction ( UNDW-IB) is specific to asthma, The mechanisms underlying UNDW-IB are not fully understood, and no reproducible animal model has been report ed, The purpose of this study was to develop a guinea-pig model of UND W-IB, Ultrasonically nebulized distilled water (UNDW) was inhaled 20 m in after an aerosolized antigen challenge in passively sensitized and artificially ventilated guineapigs, UNDW was also inhaled 5 and 20 min after 0.1 mg.mL(-1) methacholine inhalation in nonsensitized animals, In addition, 0.1 mg.kg-l S-1452, a thromboxane A(2) antagonist, or sa line was given intravenously 5 min before UNDW inhalation in sensitize d animals. The inhalation of UNDW caused bronchoconstriction, when inh aled 20 min after an antigen challenge in sensitized guinea-pigs. UNDW inhalation did not produce bronchoconstriction after saline inhalatio n in nonsensitized or sensitized guineapigs, or after antigen inhalati on in nonsensitized animals, Methacholine-induced bronchoconstriction did not evoke UNDW-IB,Neither did S-1452 reduce the UNDW-IB, In conclu sion, the guinea-pig model of ultrasonically nebulized distilled water -induced bronchoconstriction developed in this study suggests that all ergic reaction, but not bronchoconstriction, can induce bronchial hype rresponsiveness to ultrasonically nebulized distilled water, and that thromboxane A(2) is not involved in ultrasonically nebulized distilled water-induced bronchoconstriction.