van Koppen_1988_Arch.Int.Pharmacodyn.Ther_295_238

The hypothesis of an increased muscarinic receptor sensitivity in airway musculature of patients with asthma, chronic obstructive bronchitis and emphysema was investigated through methacholine-induced contraction of isolated airway smooth muscle strips. Contractile responses were recorded isotonically in tracheal smooth muscle preparations of 5 patients with chronic obstructive bronchitis, 2 patients with emphysema and 1 patient with allergic asthma, as well as in bronchial tissue preparations of 7 patients with chronic obstructive bronchitis. The responses were compared to those obtained in airway tissue preparations of 25 control subjects. The sensitivity to methacholine was normal in all groups of patients. This suggests that muscarinic receptor behaviour is normal in airway smooth muscle of patients with obstructive airway disease.