The site of action of a β -receptor stimulating drug (Fenoterol) on antigen-induced bronchoconstriction.

The influence of Fenoterol administered to the upper and lower area of the air conducting system on antigen-induced bronchoconstriction was studied in 60 dogs. In small doses, Fenoterol administered to the upper airways blocked bronchoconstriction by antigen applied to upper but not to lower airways. The intravenous administration of the same dose was without effect. In large doses, Fenoterol blocked bronchoconstriction induced at both sites. Application of both doses of Fenoterol to lower airways blocked bronchoconstriction induced at both sites and was more effective than intravenous treatment. We concluded that there is an important local effect of Fenoterol on the upper respiratory tract in antigen-induced bronchoconstriction from this site as well as on the lower airways. [ABSTRACT FROM AUTHOR]