Abstract
In the 18th century, some medical practitioners considered the main pathological feature of asthma to be the production of mucus. Later, during the 19th century, airway smooth muscle contraction was recognized to be a possible cause of airflow obstruction. However, not until 1840 was the contractility of airway smooth muscle clearly established by Charles J.B. Williams, a famous London physician. In a number of innovative experiments in dogs, rabbits, livestock and even donkeys, he showed: 1) that airways contract in response to electrical stimulation; 2) that the observed contractions are almost totally abolished by belladonna and stramonium (anticholinergics); 3) that the responses faded over time; and 4) that morphine inhibited the observed responses. Application of irritant fluids into the tracheal lumen produced similar responses. These interesting observations made by Williams will be reviewed, and related to current theories concerning modulation of airway smooth muscle responsiveness.
