PRINCIPLES UNDERLYING CILIARY ACTIVITY IN THE RESPIRATORY TRACT: III. INDEPENDENCE OF TRACHEAL CILIA IN VIVO OF DRUG AND NEUROGENOUS STIMULI

Abstract

Certain previous investigations of the responses of cilia and ciliated epithelia to chemical substances and drugs have involved bringing the cilia into direct contact with the experimental fluid being considered. This procedure is applicable when the cilia to be studied are bathed in their normal habitat by sea water, fresh water or body fluids but can hardly be indicated as an altogether desirable method for the study of ciliated epithelium of the respiratory tract. Moreover, the majority of these studies on the cilia of the respiratory tract have been made on excised tissue, which treatment may lead to error when it is sought to interpret the results in terms of functional behavior in situ. Evidence of the validity of this criticism, at least in one instance, has already been demonstrated by a comparative study made on the ciliary activity in the frog's mouth under in vivo and in vitro conditions.¹