1. The bronchial response to α-adrenoreceptor stimulation has been investigated in normal and asthmatic subjects with a specific α-receptor agonist, methoxamine hydrochloride, after atropine and β-adrenergic blockade.
2. No significant changes in forced expiratory volume in 1 s (FEV1·0) were seen in normal subjects.
3. Methoxamine inhalation caused mild symptomatic wheezing and significant falls in FEV1·0 in asthmatic subjects. No change in FEV1·0 occurred after inhalation of distilled water as control.
4. It therefore appears that methoxamine causes bronchoconstriction in asthmatic subjects through its α-adrenergic-stimulating properties, since we were not able to detect any β-receptor-blocking activity of methoxamine on the airways.