[The place of attack of beta-2 receptor stimulating bronchodilators. Fenoterol (Berotec) in allergic airway obstruction in dogs, hypersensitive to Ascaris suum].

On dogs sensitive against Ascaris suum extract an increase of the airway resistance can be caused by challenge alone on the upper part or the lower part of the airways by Ascaris suum extract. Fenoterol as beta 2-receptor stimulator is capable to decrease this reaction by deposition of this drug on the upper part as on the lower part of the airways. The effect of Fenoterol on the upper part of the airways is much stronger and lasts much longer than on the lower part of the airways or by intravenous route. A direct effect of the beta 2-receptor stimulator Fenoterol on the sensoric part of the reflex way of the reflex bronchoconstriction must be considered. It will be also discussed that the local application of Fenoterol on the upper part of the airways may influence also the reaction of the bronchial muscles in the lower part of the airways without a direct resorptive-systemic effect. The relationship of these findings for the clinical situation on man has to be investigated.