Nolte D, Berger D, Förster E
Dtsch Med Wochenschr. 1979 Feb 2;104(5):172-4. doi: 10.1055/s-0028-1103865.
25 asthma patients regularly showed an increase in respiratory resistance, as measured by the oscillation method, after propellant from a dosage aerosol had been sprayed into their buccal or nasal cavity. This effect, which was also seen in three laryngectomised patients, could be blocked by ipratropium bromide, an anticholinergic agent. Evidently it is due to a bronchoconstrictor reflex elicited by the local low-temperature stimulus produced by the propellant.