1– 3, 9 Reflex tears are the functional response to an agent irritating to the eyes, including bright light, foreign particles, and irritant substances, as well as vomiting, coughing, and yawning maneuvres.
Moreover, cancers in the upper aerodigestive tract, such as the head and neck, esophagus, stomach, and lung, may be commonly influenced by direct exposure of irritant substances by tobacco smoking and alcohol consumption.
In addition, the HET-CAM and BCOP tests confirmed the non-irritancy of KT loaded in situ gels, and HET-CAM test demonstrated the ability of ocular protection against strongly irritant substances.
It is concluded that the rat tracheal peptidergic nerves are a sensitive indicator of inhaled irritant substances.
Irritant substances and promoting agents both produce cellular hypertrophy but the respective responses can be distinguished by the much greater incidence of degenerate cells associated with irritant treatment.
Irritant substances in ETS may induce chronic inflammation in the airways that could lead to a form of irritant-induced asthma (Tarlo 2003).
Respiratory irritation, by contrast, is a nonimmu-nological state of the respiratory tract that results from inhalation of irritant substances at doses sufficient to cause inflammation.
In subjects who adapted to the experimental setup, the most irritant substances (dryer sheets and glue) triggered a physiologic (skin conductance) response accompanied with symptomatic responses in many cases.
On the other hand, CS particles deposit and evaporate sensory irritant substances including nicotine in high local concentration, when they reach the trachea, which depends on their diameter and composition in the mainstream smoke (11).
