Preliminary report on the effect of nedocromil sodium on antigen-induced early and late reactions in allergic sheep.

Allergic sheep may be considered in many respects to be an animal model of human bronchial asthma. This study investigated the effects of pretreatment with nedocromil sodium and sodium cromoglycate on antigen-induced smooth muscle contraction in vitro, and antigen-induced early and late bronchial responses and inflammatory cell influx in allergic sheep in vivo. Nedocromil sodium was found to be more potent than sodium cromoglycate against the antigen-induced smooth muscle contraction in vitro. Both drugs appeared equally effective against acute antigen-induced bronchoconstriction in sheep; both gave protection against the late response, and both agents had a similar effect on the antigen-induced response in cells obtained by bronchoalveolar lavage.