[Reactivity of the respiratory tract in healthy humans and with beta-adrenergic blockade].

Airway resistance, FEV 1.0 and lung volumes were measured in 11 normal subjects before and after voluntary hyperventilation and after inhalation of salbutamol and hyperventilation. The measurements were repeated the following day two hours after taking 40 mg propranolol. Under propranolol there is only a minimal increase in inspiratory and expiratory resistance and no change in bronchoconstriction induced by hyperventilation, but the spasmolytic effect of salbutamol is reduced. Blockade of beta-receptors is without influence on airway irritability in subjects without bronchial asthma or chronic asthmatic bronchitis. Blockade of beta-receptors can however reduce the effect of beta-2-receptor stimulants.