EFFECTS OF AEROSOL ADMINISTRATION OF A THROMBOXANE RECEPTOR ANTAGONIST (S-1452) ON EXPERIMENTAL ASTHMA IN GUINEA-PIGS

The importance of thromboxane A(2) (TXA(2)), one of the arachidonate m etabolites, in the pathogenesis of bronchial asthma has been emphasize d recently. Because aerosolized administration of antiasthmatic drugs is effective and safe, this study examined the effect of aerosolized T XA, receptor antagonist (S-1542) on allergic bronchoconstriction in pa ssively sensitized and mechanically ventilated guinea pigs. Under the cover of antihistamine, antigen-induced bronchoconstriction was marked ly inhibited by pretreatment with aerosolized S-1452 inhalation in a d ose-dependent manner. Although aerosolized S-1452 itself provoked weak bronchoconstriction for its partial agonist effect, bronchial respons iveness to inhaled histamine did not change 10 min after S-1452 inhala tion. These results indicate that aerosolized S-1452 may be useful in treating bronchial asthma.