A New System for Quantitatively Exposing Laboratory Animals by Direct Inhalation

A system for quantitatively introducing cigarette smoke into the respiratory tract of spontaneously breathing laboratory animals has been developed. At the present time, its use is restricted to animals either with tracheotomies or capable of mouth breathing. The volume, frequency, and duration of cigarette puffing is programmed and not determined by the animal’s respiratory activity. Smoke is loaded into a holding tube and inhaled during normal inhalation. To prevent anoxia, animals are allowed fresh air between puffs. The system can be automated for simultaneously exposing four to eight animals. Except for modest loss of particulate material, the composition of smoke does not appear to be altered materially.